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  • 1990-1994  (30)
  • 1985-1989
  • 1980-1984
  • 1965-1969  (12)
  • 1890-1899
  • 1992  (30)
  • 1968  (12)
  • 1895
  • Kidney
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Erscheinungszeitraum
  • 1990-1994  (30)
  • 1985-1989
  • 1980-1984
  • 1965-1969  (12)
  • 1890-1899
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    The glomerular mesangium: capillary support function and its failure under experimental conditions (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. 843-856 
    Details
    ISSN: 1432-1440
    Schlagwort(e): Kidney ; Glomerulus ; Mesangium ; Mesangial failure ; Electron microscopy ; Animal models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We present a structural analysis of the ability of the biomechanical unit consisting of mesangium and glomerular basement membrane to maintain normal capillary architecture in the face of mechanical challenges due to high intraglomerular pressures. Capillary support function may be considered in terms of the stabilization of local form (development of wall tension against capillary dilation) and global form (centripetal fixation of capillary loops to maintain higher order form). The pathologic consequences of the loss of this support are illustrated by way of experimental models of mechanical mesangial failure. Such failure may express itself as mesangial widening, increased transmesangial macromolecule “traffic,” ballooning of capillary segments, and unfolding of capillary loops. Mechanisms are described by which these structural changes may lead to segmental glomerular sclerosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00180755
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  • 2
    Digitale Medien
    Digitale Medien
    Carvedilol and the kidney (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. S127 
    Details
    ISSN: 1432-1440
    Schlagwort(e): Carvedilol ; Kidney ; Hypertension ; Renal hemodynamics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Antihypertensive drugs have differing effects on renal hemodynamics, tubular function, plasma electrolytes, and hormonal responses. Nonselective β-blockers without intrinsic sympathomimetic activites, such as propranolol, have been reported to reduce renal blood flow and to cause a modest decrease in glomerular filtration rate. Carvedilol is a new multiple action agent displaying nonselective β-blockade without intrinsic sympathicomimetic activity, α1-adrenoceptor blockade (probably responsible for its vasodilator activity), and possibly also calcium antagonist properties. The presence of these different pharmacodynamic properties results in a different effect on the kidney as compared with, e.g., propranolol. In the dog, intrarenal infusion of carvedilol resulted in a renal vasodilator response with preservation of renal blood flow and without inducing sodium retention; in contrast, propranolol induced a renal vasoconstrictor response and sodium retention in this model. A renal vasodilator response to carvedilol was also reported in spontaneously hypertensive rats (SHR) and in DOCA-salt SHR. In contrast to labetalol, i.v. infusion of hypotensive doses of carvedilol in conscious SHR did not cause sodium retention. Carvedilol was effective in controlling hypertension and preserving renal function in a rat model of progressive hypertensive renal disease. In patients with essential hypertension, carvedilol was reported to reduce renal vascular resistance in the presence of reduced perfusion pressure, allowing for normal renal autoregulation of renal blood flow. Although a small reduction in glomerular filtration rate was seen after acute administration, renal function was preserved during chronic treatment. It is concluded from these studies that renal perfusion and renal function are well maintained during acute and chronic treatment with carvedilol. The compound does not appear to cause sodium retention, and preliminary animal test data suggest the possibility of a renoprotective effect.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00207623
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  • 3
    Digitale Medien
    Digitale Medien
    Renal potassium bicarbonate release in humans exposed to an acute volume load (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. 692-697 
    Details
    ISSN: 1432-1440
    Schlagwort(e): Kidney ; Urine concentration ; Volume regulation ; Potassium ; Bicarbonate ; Aldosterone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cells of the renal medulla regulate their volume by transmembrane ion movements when exposed to large changes in osmolality. Since renal cells in culture release KHCO3 in response to hypotonic stress [11], we investigated the effect of an acute water load on urinary KHCO3 excretion in 5 healthy individuals. Water diuresis was induced by the ingestion of 1.51 hypoosmolal fluid (22 mosm/kg H2O) over 15 min. The rate of urinary volume excretion increased from an initial value of 1.4 ml/min to 9.3 ml/min after 75 min. Urinary osmolality dropped from an initial value of 940±32 mosm/kg H2O to 74±4 mosm/kg H2O (n = 5). The decrease of osmolality was accompanied by the transient release of potassium and bicarbonate. Peak values of KHCO3 excretion were observed between 30 and 45 min after the onset of the experiment corresponding to the drop of urinary osmolality. The magnitude of renal potassium release correlated significantly (r=0.93; P 〈 0.05) with endogenous plasma aldosterone concentrations measured prior to the experiment in the 5 volunteers. We conclude that medullary epithelial cells release KHCO3 when exposed to hypotonic stress. The volume regulatory response is upregulated by aldosterone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00180288
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  • 4
    Digitale Medien
    Digitale Medien
    Caries susceptibility and renal excretion of calcium (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. 735-739 
    Details
    ISSN: 1432-1440
    Schlagwort(e): Kidney ; Calcium ; Phosphate ; Sodium ; Caries
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Clearance studies were performed for 2 days in two groups of age-matched young female volunteers: those with low caries prevalence and those with high caries prevalence. Both groups were kept on a low-calcium diet for 1 week and received 0.5 g calcium at the beginning of the second day. In both groups, glomerular filtration rate, urinary flow rate and renal excretions of sodium, calcium, and phosphate were subject to significant circadian variations. In both groups the administration of calcium led to a significant increase in renal excretion of sodium and calcium and a significant decrease in that of phosphate. On the first day, calcium excretion was significantly greater in those with low caries prevalence than in those with high caries prevalence, pointing to altered calcium homeostasis in this group.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00180739
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  • 5
    Digitale Medien
    Digitale Medien
    Activation of β2-adrenoceptors by isoprenaline and adrenaline enhances noradrenaline release in cortical kidney slices of young spontaneously hypertensive rats (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 345 (1992), S. 25-32 
    Details
    ISSN: 1432-1912
    Schlagwort(e): 3H-noradrenaline release ; SHR ; Kidney ; Prejunctional β-adrenoceptors ; Adrenaline ; Isoprenaline ; cAMP
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The aim of the present study was to investigate β-adrenoceptor modulation of noradrenaline release from sympathetic nerves in superfused cortical kidney slices of 4-week-old spontaneously hypertensive rats (SHR) and age-matched controls (WKY). After preincubation with 3H-noradrenaline the kidney slices were electrically stimulated in superfusion chambers. The stimulation induced (S-I) outflow of radioactivity was mainly composed of unmetabolized 3H-noradrenaline in both strains and thus taken as an index of noradrenaline release. There was a frequency-dependent (1.25–20 Hz) increase in the S-1 outflow of radioactivity. At all stimulation frequencies tested S-I outflow of radioactivity was similar or even slightly lower in SHR than in WKY kidney slices in either the absence or presence of cocaine (10 μmol/l). The non-selective β-adrenoceptor agonists isoprenaline (0.l gmol/1) and adrenaline (0.01 and 0.1 μmol/l) enhanced S-I outflow of radioactivity. The facilitatory effects of isoprenaline (0.1 μmol/l) and adrenaline (0.1 μmol/l) were blocked by the selective β2-adrenoceptor antagonist ICI 118551 (0.1 μmol/l) but not by the selective β1-adrenoceptor antagonist atenolol (0.3 μmol/l). The cell-permeable CAMP analogue 8-bromo-cAMP (300 μmol/l) enhanced S-1 outflow of radioactivity to a similar extent in both SHR and WKY kidney slices. A combination of 8-bromo-cAMP (300 μmol/l) and adrenaline (0.1 μmol/l) did not enhance S-1 outflow of radioactivity to a greater extent than 8-bromo cAMP (300 μmol/l) alone in both strains. However, the facilitatory effects of isoprenaline (0.1 μmol/l) and adrenaline (0.1 μmol/l) but not that of adrenaline (0.01 μmol/l) were significantly greater in SHR than in WKY. The results suggest that stimulation of prejunctional β2-adrenoceptors by adrenaline even in the absence of a-adrenoceptor blockade enhances noradrenaline release in kidney cortex of young SHR and WKY. This β2-adrenoceptor mediated effect may possibly be dependent on cAMP formation. The greater facilitatory effects of isoprenaline (0.1 μmol/l) and adrenaline (0.1 μmol/l) in SHR as compared to WKY are in accord with receptor binding studies which show a higher density of β2-adrenoceptors in SHR than in WKY kidney cortex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00175465
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  • 6
    Digitale Medien
    Digitale Medien
    Influence of antihypertensive therapy on renal function (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. S120 
    Details
    ISSN: 1432-1440
    Schlagwort(e): Hypertension ; Kidney ; Antihypertensive drugs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Antihypertensive therapy influences kidney function by different mechanisms depending on the mode of action of the drug used. The GFR is improved by calcium entry blockers and ACE inhibitors, unaffected by vasodilators, α-blockers and centrally acting sympatholytics and impaired by β-blockers. The same is true for renal blood flow and is due to changes of renal vascular resistance. Renal sodium excretion is impaired mostly by vasodilators, by α-blockers, sympatholytics and β-blockers; in contrast, calcium entry blockers and ACE inhibitors acutely induce natriuresis. The RAAS is stimulated by vasodilators, unaffected by α-blockers and sympatholytics and suppressed by β-blockers. Plasma catecholamines are stimulated by vasodilators and suppressed by centrally acting sympatholytics and unaffected by the others. Induction of acute renal functional impairment is reported for ACE inhibitors under conditions of compromised renal perfusion pressure such as in renal artery stenosis. These data from the literature reviewed are supported by our own experimental data on sodium balance under different drugs and micropuncture data in experimental renal artery stenosis. To achieve effective antihypertensive treatment with a low profile of side effects, careful monitoring of renal function seems to be mandatory.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00207622
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  • 7
    Digitale Medien
    Digitale Medien
    Ca2+ uptake by endoplasmic reticulum of renal cortex. II. Effects of uninephrectomy and parathyroidectomy (1992)
    Springer
    Calcified tissue international 51 (1992), S. 42-47 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Kidney ; Endoplasmic reticulum ; Calcium ; In vivo
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Calcium uptake by the endoplasmic reticulum (ER) is important for cellular calcium homeostasis, yet its regulation in nonmuscle cells is poorly understood. We reported that Ca2+ uptake by a light fraction of canine renal cortical ER (LER) is stimulated by protein kinase C in vitro. Here we describe conditions in vivo that stimulated renal cortical LER Ca2+ uptake. Thirty minutes after contralateral nephrectomy in the dog, 45Ca2+ uptake into renal cortical LER was increased 42% above control LER. There was no difference in LER Ca2+ uptake 24 hours after uninephrectomy. Acute denervation did not reproduce the increase in LER 45Ca2+ uptake seen at 30 minutes after uninephrectomy, nor did prior thyroparathyroidectomy abolish it. Forty-eight hours after thyroparathyroidectomy, 45Ca2+ uptake activity into renal cortical LER was decreased ≈sevenfold. In a proximal tubular cell line (LLC-PK1), 30-minute incubation with 12-O-tetradecanoylphorbol-13-acetate doubled 45Ca2+ uptake into a nonmitochondrial pool. Pretreatment with epidermal growth factor halved ER Ca2+ uptake, whereas insulin-like growth factor and growth hormone, alone or in combination, had no effect. Our data suggest that Ca2+ uptake into renal cortical ER is stimulated acutely during compensatory renal growth, perhaps through protein kinase C, and is stimulated chronically by parathyroid hormone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00296216
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  • 8
    Digitale Medien
    Digitale Medien
    Arteries and veins formed within renal vessels: a previously neglected observation (1992)
    Springer
    Virchows Archiv 420 (1992), S. 301-304 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Kidney ; Blood vessels ; Arterialisation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An abnormality of blood vessels was noted in a biopsy of a renal transplant. This took the form of apparent development of a new artery inside and concentric with the old, with elastic laminae and a muscular media, separated from the old internal elastic lamina by poorly cellular tissue. In a systematic study of material from another 119 renal transplants, 13 nephrectomy specimens for chronic pyelonephritis and hydronephrosis, 28 renal biopsies showing interstitial nephritis, and 18 renal biopsies showing small vessel vasculopathy of accelerated hypertensive type, similar arterial changes were seen in another 10 renal transplants that showed chronic vascular rejection, 1 case of chronic interstitial nephritis, and 3 cases of vasculopathy, 2 with accelerated hypertension and 1 with systemic sclerosis. One renal transplant also showed apparent development of new muscular veins inside old veins. Immunohistological study for smooth muscle actin confirmed that the apparently new arterial and venous structures contained smooth muscle cells. The arterial abnormality may be called arterialisation of intrarenal arteries. This change appears to be not rare, is distinctive, and has scarcely been previously recognised or reported as a response of intrarenal blood vessels to damage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01600208
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  • 9
    Digitale Medien
    Digitale Medien
    The renin-secreting cell and the glomerular peripolar cell in renal artery stenosis and Addison's disease (1992)
    Springer
    Virchows Archiv 420 (1992), S. 533-537 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Peripolar cell ; Renin ; Juxtaglomerular apparatus ; Kidney
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The glomerular peripolar cell may be a secretory component of the juxtaglomerular apparatus. To investigate this hypothesis we studied kidneys with the renin-angiotensin system activated by two different stimuli in order to compare the responses of peripolar cells and renin-secreting cells. We examined 10 human kidneys, removed for renal artery stenosis and 11 autopsy cases of Addison's disease with appropriate controls. We counted granulated peripolar cells in serial paraffin-embedded sections and renin-containing cells were quantified using an immunoperoxidase technique with an antiserum to human renin. There was a five-fold increase in the number of renin-containing cells in both renal artery stenosis and in untreated, but not in treated, Addison's disease. Peripolar cells were increased in number in three cases of renal artery stenosis, but were unaltered in both treated and untreated Addison's disease. Therefore, neither a reduction in renal perfusion pressure (renal artery stenosis), nor sodium depletion (Addison's disease) consistently affect peripolar cells in humans. These findings do not support the hypothesis that the peripolar cell is part of the juxtaglomerular apparatus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01600259
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  • 10
    Digitale Medien
    Digitale Medien
    Analysis of kidney volume growth during the fetal period in humans (1992)
    Springer
    Urological research 20 (1992), S. 271-274 
    Details
    ISSN: 1434-0879
    Schlagwort(e): Kidney ; Fetal kidney ; Renal volume ; Renal growth ; Fetal urology ; Renal anomalies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The growth of fetal kidney volume was studied in 290 specimens taken from 145 fresh human fetuses (85 males and 60 females) with gestational age ranging from 13 to 36 weeks postconception (WPC). Normative equations and curves of the growth of renal volume were obtained for male and female fetuses and for the whole sample in the second trimester (13–24 WPC) and in the third trimester (25–36 WPC) of gestation. There was no difference between the growth in volume of the right and left kidneys. Fetal kidney volume increases with a more intense rhythm in the early fetal period (13–24 WPC). During the second trimester, there was no difference between the values for renal volume of male and female fetuses. In the third trimester, male fetuses had renal volumes significantly greater than the female fetuses. The normative parameters of renal volume could have practical applications in detection and monitoring of renal anomalies in fetal and perinatal urology.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300257
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  • 11
    Digitale Medien
    Digitale Medien
    Effect and distribution of intravenously injected 125I-endothelin-1 in rat kidney and lung examined by electron microscopic radioautography (1992)
    Springer
    Anatomy and embryology 185 (1992), S. 87-96 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Kidney ; Endothelium ; Glomerular mesangium ; Lung ; Autoradiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The morphological effect of endothelin-1 (ET-1) and the distribution of endothelin-binding sites on the kidney and lung was investigated ultrastructually by intravenous injection of [125I]-ET-1 into rats. About 10% decrease of the diameter of glomeruli was observed at 10 min after the injections of ET-1 or [125I]-ET-1 (1.3–2.4 nmole/kg). When localization of [125I]-ET-1 in the kidney was examined by light and electron microscopic radioautography, silver grains were preferably localized on the fenestrated endothelial cells of glomeruli and peritubular capillary endothelial cells. Some grains were also localized on the interdigitating processes of urinary tubules. Quantitative analysis of silver grains in the glomeruli showed that 83% of grains were located on the fenestrated endothelial cells, 12% on the podocytes of visceral cells, and 5% on mesangial cells at 10 min. After 60 min, 50% of silver grains were incorporated into the cytoplasm of fenestrated endothelial cells. In contrast to glomeruli, silver grains were rare on the arteries and large arterioles. However, a few silver grains were often observed on the smooth muscle cells of small arterioles (8–20 μm in diameter). In the lung, 70% of silver grains were located on the alveolar capillary endothelial cells. These results indicate the abundance of ET receptors on the glomerular fenestrated endothelium, peritubular fenestrated endothelium and alveolar capillary endothelium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213604
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  • 12
    Digitale Medien
    Digitale Medien
    Development of the metanephros in the chick: maturation of glomerular size and nephron length (1992)
    Springer
    Anatomy and embryology 185 (1992), S. 291-297 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Kidney ; Nephron development ; Chick
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In the avian kidney three nephron types may be identified: mammalian-type nephrons with long (MTN-I) and short (MTN-II) loops of Henlé, and reptilian-type nephrons (RTN). By the method of microdissection the maturation of the nephrons of domestic fowl kidney has been studied. From the 14th day of incubation it is possible to isolate the MTN-I which appear first; all three nephron types may be isolated after 18 days of incubation. The thin limb of Henlé's loop in MTN-I appears after hatching, and the length of this segment in 1-day-old chicks is 0.1–0.13 mm. In 60-day-old chicks its length has approximately doubled. The transition of the thin segment to the thick segment is situated in the descending part of Henlé's loop. In the course of development, the relative length of all nephron segments in MTN-I increases uniformly, while in MTN-II and in RTN the relative length of the proximal and distal convoluted tubules increases. At all stages of development, MTN-I are the longest among the three groups of nephrons and have the largest glomeruli. The comparison between developing avian and mammalian kidneys shows great similarities in the process of maturation in analogous nephron types in these two classes of vertebrates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00211828
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  • 13
    Digitale Medien
    Digitale Medien
    Structural relationships between the endothelial actin system and the underlying elastic layer in the distal interlobular artery of the rat kidney (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 467-476 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Artery ; Endothelial cell ; Stress fiber ; Elastic fiber ; Kidney
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The structure of the intracellular actin filaments and the extracellular matrices was studied in the distal interlobular arteries in the rat kidney, employing three different morphological techniques, including rhodamin-phalloidin staining of cryosections, resorcin-fuchsin staining of paraffin sections, and a cold dehydration procedure for electron microscopy. The endothelial cells possess longitudinally running stress fibers. The inner elastic layer is composed of meshworks of elastic fibers encompassing numerous pores. The smooth muscle cells containing abundant actin filaments are arranged circumferentially around the vascular axis. The endothelial stress fibers are found mainly in the basal half of the endothelial cells, and anchor onto the basal cell membranes. The elastic meshworks send off longitudinal branch fibers to contact the endothelial cell membranes at the anchoring sites of stress fibers. In addition circumferential branches run toward the smooth muscle cells. The functional significance of the intracellular contractile apparatus and the extracellular tensile component in small arteries was discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00185460
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  • 14
    Digitale Medien
    Digitale Medien
    Transient increase in renal insulin-like growth factor binding proteins during initial kidney hypertrophy in experimental diabetes in rats (1992)
    Springer
    Diabetologia 35 (1992), S. 589-593 
    Details
    ISSN: 1432-0428
    Schlagwort(e): Kidney ; hypertrophy ; insulin-like growth factors ; insulin-like growth factor binding proteins ; streptozotocin ; diabetes ; rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The insulin-like growth factors, insulin-like growth factor I and insulin-like growth factor II are bound to six distinct classes of insulin-like growth factor binding proteins (IGFBPs) in the circulation and in extracellular fluids. Diabetic renal hypertrophy is preceded by a transient increase in kidney insulin-like growth factor I suggestive of a renotropic function for insulin-like growth factor I. In order to examine a possible involvement of IGFBPs in initial diabetic kidney growth and in kidney insulin-like growth factor I accumulation, we studied rat kidney IGFBPs by ligand blotting during the first 4 days after induction of diabetes. Six distinct bands were identified in kidney and liver tissue with apparent molecular weight values of 38–47 (doublet), 34, 30, 24 and 20 kDa. The 38–47 kDa doublet band probably corresponds to the insulin-like growth factor binding subunit of IGFBP-3, the 24 kDa band to IGFBP4 and the 30 kDa band to IGFBP-1 and/or IGFBP-2, as these IGFBPs in rats have similar molecular weight. In untreated diabetic rats a transient increase in the kidney 30 kDa band was demonstrable 24 h after induction of diabetes with a maximal rise (two-fold) after 48 h, followed by a decrease to baseline values after 4 days. In untreated diabetic rats the 38–47 kDa doublet band also increased (two-fold) in kidney during the first 2 days after induction of diabetes, followed by a subsequent decrease. Insulin-treatment prevented both the increase in the 30 kDa and in the 38–47 kDa bands. Kidney weight in untreated diabetic rats increased by 26 % after 4 days. In conclusion, the present study shows a transient increase in the 30 kDa and the 38–47 kDa IGFBP species in hypertrophying diabetic kidneys, contemporarily with the previously described transient increase in extractable kidney insulin-like growth factor I content. These findings support the concept that IGFBPs may be involved in the action of insulin-like growth factor I and possibly in the diabetic kidney insulin-like growth factor I accumulation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00400489
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  • 15
    Digitale Medien
    Digitale Medien
    Renal arteries: anatomic study for surgical and radiological practice (1992)
    Springer
    Surgical and radiologic anatomy 14 (1992), S. 113-117 
    Details
    ISSN: 1279-8517
    Schlagwort(e): Kidney ; Renal artery ; Multiple renal arteries ; Renal transplantation ; Renal angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé La vascularisation artérielle du rein a été analysée à partlr de 266 dissections provenant de 133 sujets d'anatomie. Les résultats anatomiques sont les suivants: une seule artère hilaire est présente dans 53,3% des cas; une artère hilaire associée à une branche polalre supérieure extrahilaire dans 14,3% des cas; deux artères hilaires dans 7,9% des cas; trois artères hilaires dans 1,9% des cas; une artère polaire supérieure dans 6,8% des cas; une artère polaire inférieure dans 5,3% des cas; enfin d'autres variations dans 8,5% des cas. Sont envisagées les applications urologiques et radiologiques de ces constatations dans la transplantation rénale, la pathologie hypertensive d'origine rénale, la traumatologie rénale, la radiologie interventionnelle, la chirurgie conservatrice et l'oncologie.
    Notizen: Summary The renal arterial supply was analyzed in 266 kidneys dissected from 133 fixed adults subjects. The anatomical findings are presented: 1 hilar artery in 53.3% of the cases, 1 hilar artery with 1 superior pole extra-hilar branch in 14.3%, 2 hilar arteries in 7.9%, 3 hilar arteries in 1.9%, superior polar artery in 6.8%, inferior polar artery in 5.3% and other variations in 8.5%. The urological and radiological implications of these findings in kidney transplantation, renovascular hypertension, renal trauma, interventional radiology, conservative surgery and oncologic surgery are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01794885
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  • 16
    Digitale Medien
    Digitale Medien
    Ca2+ uptake by endoplasmic reticulum of renal cortex. I. Ionic requirements and regulation in vitro (1992)
    Springer
    Calcified tissue international 51 (1992), S. 35-41 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Kidney ; Endoplasmic reticulum ; Calcium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary A subcellular fraction enriched in cytochrome c reductase (7.9-fold) and relatively de-enriched (0.64-fold) in Na+/K+-ATPase was prepared from canine kidney cortex by sucrose density gradient ultracentrifugation. It was shown by electron microscopy to consist primarily of a light fraction of endoplasmic reticulum (LER). LER vesicles displayed ATP-dependent 45Ca2+ uptake that was insensitive to 10 mM KCN or NaN3, and was promptly released by 20 μM A23187 or ionomycin. Inositol-1,4,5-trisphosphate (IP3) appeared to produce a time-dependent release of 45Ca2+. Vanadate inhibited 45Ca2+ uptake with a Ki≈0.3 mM, further suggesting that the activity resided in the ER rather than the plasma membrane. 45Ca2+ uptake by LER, at 5 μM total [Ca2+], displayed a strong dependence on divalent cations (Mg2+〉Co2+〉Mn2+≫Ba2+≥Cd2+≥Sr2+, present at 2 mM) as well as on monovalent cations (Na+≥K++Na+ 〉K+〉Li+〉choline+), and anions (Cl-〉acetate-≥NO3 -≥F-〉H2PO4 -≫gluconate-≥oxalate=≫SO4 =). It had a fairly narrow pH optimum (7.25–7.50). Preincubation (10 min) of LER vesicles with 12-O-tetradecanoylphorbol-13-acetate (TPA) stimulated LER Ca2+ uptake; this effect was enhanced in the presence of renal cytosol [5% (vol/vol)]. However, Ca2+ uptake was not affected by preincubation with dibutyryl cyclic AMP, calmodulin, or 1,25-(OH)2-vitamin D3, either in the absence or presence of renal cytosol. Thus, the Mg2+-ATP dependent 45Ca2+ uptake activity of this canine renal cortical LER fraction displays modulation by IP3, TPA, and pH that appears to be physiologically relevant.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00296215
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  • 17
    Digitale Medien
    Digitale Medien
    Pharmacokinetics and tolerance of Gd-DOTA (DOTAREM) in healthy volunteers and in patients with chronic renal failure (1992)
    Springer
    European radiology 2 (1992), S. 326-329 
    Details
    ISSN: 1432-1084
    Schlagwort(e): Gd-DOTA ; Contrast media ; Kidney ; Renal failure ; Pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The aim of this study was to assess the pharmacokinetics and tolerance of Gd-DOTA (DOTAREM) in non-dialysed patients with chronic renal failure. Eight patients with chronic renal failure (creatinine clearance between 10 and 60 ml/min) and four healthy volunteers were given i.v. Gd-DOTA (0.1 mmol/kg). Blood and urine samples were collected. Gd-DOTA tolerance was also studied (vital signs, biological parameters, adverse reactions). In healthy volunteers, Gd-DOTA was rapidly distributed in the extracellular space and almost totally eliminated in the urine (glomerular filtration, 93.3±4.7% of the dose 24 h post injection). In patients with chronic renal failure, a delayed and almost total urinary elimination observed with a correlation between Gd-DOTA clearance and plasma creatinine clearance (r = 0.964). Tolerance was good with no significant modification of renal function or other parameters. These results confirm previous studies and indicates that DOTAREM can be used safely for patients with chronic renal failure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00175436
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  • 18
    Digitale Medien
    Digitale Medien
    Ethical and psychological aspects of living donorship and life with a donated organ (1992)
    Springer
    European journal of pediatrics 151 (1992), S. S76 
    Details
    ISSN: 1432-1076
    Schlagwort(e): Ethics ; Psychology ; Living organ transplantation ; Paediatrics ; Kidney
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract There is far-reaching consent in the literature that public and consensual agreements on the basics of the different aspects of medical ethics are inalienable before the instigation of any innovative transplant procedure. In the case of a certain method and/or of an individual patient, however, the ultimate ethical evaluation can most likely never be entirely complete before this application. Ethical evaluation depends on the actual criteria used, the present knowledge regarding the risk-benefit-balance as well as on the ethical evaluation of the patient's and his family's own feelings and expectations which are not entirely conscious. In relation to the so-called “fundamental and constant ethical guidelines” and under a psychological perspective potential, ethical conflict constellations are presented which have to be dealt with in the process of ethical and psychological evaluation before living organ transplantation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02125808
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  • 19
    Digitale Medien
    Digitale Medien
    Cell proliferation induced in the kidneys and livers of rats and mice by short term exposure to the carcinogen p-dichlorobenzene (1992)
    Springer
    Archives of toxicology 66 (1992), S. 503-507 
    Details
    ISSN: 1432-0738
    Schlagwort(e): Kidney ; Liver ; Cell proliferation ; Rat ; Mouse ; p-Dichlorobenzene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Cell proliferation in the kidneys and livers of rats and mice exposed short-term to p-dichlorobenzene (p-DCB) was evaluated by immunohistochemical measurement of bromodeoxyuridine (BrdU) incorporation into nuclei of DNA-synthesizing cells. p-DCB was given by gavage at two doses up to 600 mg/kg body weight for 4 days. The cumulative fraction of proliferating cells was increased in the proximal tubule epithelial cells of male rats at the high dose, but not at the low dose nor in females at either dose using gamma-glutamyl transferase reaction to identify tubular cells. Also, no increase in cell proliferation was found in mouse kidneys. The fractions of proliferating cells in the livers of rats and mice of both sexes were also increased. The increased cell proliferation in only male rat kidney and in the livers of mice of both sexes correlates with the reported carcinogenic effects of p-DCB in those tissues. However, the finding that p-DCB also induced cell proliferation in the livers of rats of both sexes, which were not a site of p-DCB-induced tumors in bioassays, and in female mice at the low dose, which was not affected by an increase in tumors, reveals a lack of concordance and indicates that acute induction of cell proliferation is not sufficient to lead to carcinogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01970676
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  • 20
    Digitale Medien
    Digitale Medien
    Renal transplantation in infants, a therapeutic option? (1992)
    Springer
    European journal of pediatrics 151 (1992), S. S13 
    Details
    ISSN: 1432-1076
    Schlagwort(e): Kidney ; Transplantation ; Infant ; Uremia ; Development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Renal transplantation is widely accepted as the treatment of choice for endstage renal failure in childhood. Since dialysis is regularly applied to infants with renal failure, the question logically arises, can infants also receive renal transplants and what are the outcomes? A review of the literature and the clinical experience at the University of Minnesota supports the performance of renal transplantation in infancy. Present patient and graft survival rates for infants are indistinguishable from those of older children. While living adult donors are preferred, adult cadaveric kidneys have also been successfully transplanted. Following successful transplantation, the infants have generally enjoyed “catch-up” growth and accelerated psychomotor development. While there may be problems related to fluid and electrolyte balance in these smallest patients, the majority of the problems encountered mirror those seen in any child undergoing transplantation. Renal transplantation is regularly successful in infancy and should be considered an integral component of the therapy for any child with chronic renal failure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02125797
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  • 21
    Digitale Medien
    Digitale Medien
    Sodium-taurine cotransport in reptilian renal brush-border membrane vesicles (1992)
    Springer
    Pflügers Archiv 421 (1992), S. 168-175 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Taurine ; Kinetic ; Stoichiometry ; Amino acid transport ; β-Amino acid ; Membrane vesicle ; Kidney ; Sodium-coupled transport
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The coupled transport of Na+ with taurine into snake renal brush-border membrane vesicles (BBMV) was studied using 5-s uptake conditions. Taurine transport into snake renal BBMV involved two parallel processes, one saturable (Na+-dependent) and one (Na+-independent) that behaved like passive diffusion. Below 1 mM taurine concentration, the Na+-dependent system accounted for 60% of total taurine uptake. Over both low (0.001–0.80 mM) and high (0.8–5.0 mM) taurine concentration ranges, the Na+-dependent taurine uptake within each range showed Michaelis-Menten kinetics, suggesting the presence of two independent saturable Na+-dependent transport systems for taurine. The high-affinity, low-capacity system saturated above 100 μM with a K m of 71.4±45.7 μM and a maximum velocity (V max) of 21.9±3.77 pmol (mg protein)−1 (5 s)−1. The low-affinity, high-capacity system saturated above 1 mM, with a K m of 1.11±0.63 mM and a V max of 252±47 pmol (mg protein)−1 (5 s)−1. The stoichiometric relationship between external Na+ concentration and taurine uptake (at 10 μM) by the high-affinity BBMV transport system was examined by the activation method under short-circuited conditions. The 5-s rate of taurine transport was a sigmoid function of increasing extravesicular Na+ concentration. Kinetic analysis of the interaction of Na+ with the high-affinity taurine transport system suggested that 3 Na+ ions (3.2±0.7) may be involved with 1 taurine molecule in the transport event. The data suggest the presence of a highly efficient and high-affinity reabsorptive taurine transport system on the luminal membrane of the kidney of the garter snake, a species that can secrete taurine in vivo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00374824
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  • 22
    Digitale Medien
    Digitale Medien
    Distribution of histamine in the rat kidney during pregnancy and development (1992)
    Springer
    Cell & tissue research 267 (1992), S. 233-239 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Development, ontogenetic ; Kidney ; Glomerulus ; Distal convoluted tubule (DCT) ; Histamine ; Immunohistochemistry ; Hybridization, in situ ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An antiserum against conjugated histamine and two oligonucleotide probes that detect the mRNA encoding L-histidine decarboxylase (HDC) involved in histamine synthesis were used to study the appearance of histamine and its location in the kidneys of fetal, newborn and young postnatal rats and in the kidneys of pregnant rats. On embryonic days 16 and 18 (E16 and E18), some HA-immunoreactive (HA-ir) cells were found within the largest S-shaped bodies. Histamine was found to appear rapidly between the 18th and 20th embryonic days in the convoluted tubules of the kidneys. On postnatal day 0 (P0), the distal convoluted tubules and collecting ducts exhibited bright fluorescence, the intensity of which decreased quickly so that it was faint on day P4 and absent at later stages. In kidneys of pregnant rats HA-ir was found in the epithelium of both the Bowman's capsule, collecting ducts and in a few cells within the tubules. Nonuniform HA-ir was also detected within glomeruli. No evidence for the presence of L-histidine decarboxylase mRNA in kidneys of fetuses or pregnant rats was seen. It is concluded that distinct structures in the developing rat kidney contain histamine during a period around birth from day E20 to day P4. In the pregnant rat, the epithelium that is in direct contact with the urine flow is immunoreactive for histamine from day 16 to 20 of pregnancy. The results suggest that histamine is not synthesized locally in the kidneys but rather originates from other tissues.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00302960
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  • 23
    Digitale Medien
    Digitale Medien
    Total numbers of glomeruli and individual glomerular cell types in the normal rat kidney (1992)
    Springer
    Cell & tissue research 270 (1992), S. 37-45 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Kidney ; Glomerulus ; Stereology ; Morphometry ; Disector ; Quantitative methods, structural ; Rat (Sprague Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Alterations in numbers of glomeruli and glomerular cells occur in various renal disorders. Although values for these parameters have previously been reported for several species, the estimates have often been biased due to assumptions regarding glomerular and/or nuclear size and shape. Other studies have used tedious serial-section reconstruction methods. In the present study, unbiased stereological methods were used to estimate total numbers of glomeruli and individual glomerular cell types in normal rats. The kidneys of seven adult Sprague-Dawley rats were perfused with 4% paraformaldehyde and 1% glutaraldehyde in phosphate buffer and embedded in either glycolmethacrylate (for light microscopy, LM) or Epon/Araldite (for transmission electron microscopy, TEM). Total glomerular number was estimated using an LM physical disector/fractionator combination; the total number of cells per average glomerulus was estimated using an LM optical disector/ Cavalieri combination; and TEM physical disectors were used to count individual cell types. The normal rat kidney was found to contain 31764±3667 (mean±SD) glomeruli. An average glomerulus contained 674±129 cells, of which 181±53 were epithelial cells (podocytes), 248±53 were endothelial cells, and 245±45 were mesangial cells. An average renal corpuscle contained 117±27 parietal epithelial cells. Following sectioning and staining, less than 6.5 h was needed to obtain the above estimates for a single animal, with coefficients of variation (SD as a percent of the mean) ranging from 10% to 25%. The unbiased stereological methods used in the present study constitute an unbiased, precise and cost-efficient set of quantitative tools for assessing glomerular morphology in health and disease.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00381877
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  • 24
    Digitale Medien
    Digitale Medien
    Confocal microscopic and other observations on the distal end of the thick limb of the human loop of Henle (1992)
    Springer
    Cell & tissue research 267 (1992), S. 11-16 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Kidney ; Distal tubule ; Tamm-Horsfall protein ; Cytokeratin ; Immunohistochemistry ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Various antibodies and lectins were used in a histological study of the human renal tubule, particularly of the distal end of the thick limb of the loop of Henle. The thick limb, identified by antibody to Tamm-Horsfall protein, ended abruptly, either at the macula densa or at a variable distance after it. At this point there was an abrupt change in cell size. Confocal microscopy and other techniques showed that this point marked an abrupt beginning of tubular staining by the cytokeratin antibody PKK 2 and the lectin UEA 1, with an abrupt end of staining by the lectin DBA. Distal from this point, there were gradual changes in staining of the tubule by various reagents including other antibodies to cytokeratins. These structural findings suggest that there is a fundamental change in the tubule at the end of the thick limb. The abrupt end to the thick limb in man resembles that seen in the rat and the rabbit.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318686
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  • 25
    Digitale Medien
    Digitale Medien
    Immunohistochemical localization of transthyretin in glomerular peripolar cells of newborn sheep (1992)
    Springer
    Cell & tissue research 267 (1992), S. 193-197 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Transthyretin ; Kidney ; Peripolar cells ; Sheep, newborn
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Purified transthyretin has been isolated from sheep serum. Antiserum raised against this protein has been used with an indirect immunoperoxidase histochemical technique to identify transthyretin in newborn lamb kidney tissue. Transthyretin was found in proximal tubule cells and in glomerular peripolar cells. Preabsorption studies using purified transthyretin protein indicate that the immunoreactivity of the antiserum is specific to transthyretin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318704
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  • 26
    Digitale Medien
    Digitale Medien
    Non-granulated peripolar cells exist in the rat glomerulus (1992)
    Springer
    Cell & tissue research 268 (1992), S. 567-570 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Peripolar cell ; Glomerulus ; Kidney ; Cytoplasmic granules ; Scanning electron microscopy ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The peripolar cell is a unique cell type in the mammalian glomerulus. Peripolar cells are said to be identifiable during light microscopy by their cytoplasmic granules and by their position at the vascular pole; and during scanning electron microscopy by their distinctive surface morphology. We used both techniques to count peripolar cells in 6 normal rat kidneys. Scanning microscopy revealed that 55(±5)% of glomeruli contained at least one peripolar cell whereas light microscopy revealed granulated peripolar cells in only 4(±2)% of glomeruli. Vascular poles which contained peripolar cells previously identified by scanning were then examined by light and by transmission electron microscopy. Serial sections through these peripolar cells demonstrated the absence of cytoplasmic granules. Our observations suggest that the majority of peripolar cells in the rat contain no granules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319164
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  • 27
    Digitale Medien
    Digitale Medien
    The structure and biochemistry of the vacuolar H+ ATPase in proximal and distal urinary acidification (1992)
    Springer
    Journal of bioenergetics and biomembranes 24 (1992), S. 351-359 
    Details
    ISSN: 1573-6881
    Schlagwort(e): Kidney ; collecting tubule ; intercalated cells ; urinary acidification ; acid-base balance ; proton pump ; V-ATPase ; regulatory proteins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Physik
    Notizen: Abstract Vacuolar H+ ATPases participate in renal hydrogen ion secretion in both the proximal and distal nephron. These plasma membrane forms of the vacuolar H+ ATPase are regulated physiologically to maintain the acid-base balance of the organism. Proton transporting renal cells have requirements for constitutive acidification of intracellular compartments for normal endocytic and secretory functions. Recent experiments have begun to reveal how the kidney regulates these proton pumps independently. Vacuolar H+ ATPases are a family of structurally similar enzyme which differ in the composition of specific subunits. Cytosolic regulatory enzymes are present in renal cells which may affect vacuolar H+ ATPases in certain membrane compartments selectively. The vacuolar H+ ATPase in the plasma membrane of intercalated cells resides in a specialized proton-transporting apparatus that translocates the enzyme between an intracellular membrane pool and the plasma membrane in response to physiologic stimuli.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00762528
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  • 28
    Digitale Medien
    Digitale Medien
    Traumatische Ruptur eines Nierentransplantats in eine chronische Lymphozele (1992)
    Springer
    Langenbeck's archives of surgery 377 (1992), S. 222-225 
    Details
    ISSN: 1435-2451
    Schlagwort(e): Lymphocele ; Kidney ; Transplantation ; Rupture ; Trauma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Lymphozelen sind eine seltene Komplikation nach Nierentransplantationen (in unserem Krankengut 2,2%) und treten typischerweise in den ersten 3–4 Monaten nach der Transplantation auf. Im späteren Verlauf sind sie eine Rarität. Die traumatische Ruptur eines Nierentransplantats ist in unserem Krankengut mit über 1200 Nierentransplantationen bisher einmalig. Es wird der Fall eines 28jährigen Marines geschildert, der 19 Jahre nach der Transplantation eine traumatische Nierentransplantatruptur erleidet. Durch das Trauma wird eine vorbestehende chronische Lymphozele klinisch manifest. Die Histologic der Lymphozelenwand zeigt Fett- und Bindegewebe mit ausgeprägter Fibrose. Das diagnostische und therapeutische Vorgehen wird beschrieben und mögliche Zusammenhänge den beiden seltenen Ereignisse diskutiert.
    Notizen: Summary The lymphocele is a seldom complication after kidney transplantation (2.2% of our patients). This manifestation occurs typically 3–4 months after transplantation, as a late complication it's a rarity. The rupture of a kidney graft because of a trauma is unique in our clinical experience, which contains more than 1200 kidney transplantations. We report the case of a 28-year-old man who had 19 years after transplantation a traumatic rupture of the kidney graft. Because of the trauma a preexistent chronic lymphocele got clinically manifest. The histology of the lymphocele wall shows fatty and collagen tissue with a strong fibrosis. The diagnostic and therapeutic procedure is described. There are different possible relations between the rare problems: — the tight lymphocele carries over the force on the graft — the lymphocele has grown together with the graft at the lower pole and ruptures in this place — a little graft rupture makes a clinical manifest bleeding in the lymphocele because the deficiency of perirenal tissue.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210277
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  • 29
    Digitale Medien
    Digitale Medien
    Cutaneous ion exchange, and renal and extrarenal partitioning of acid and ammonia excretion in the larval tiger salamander, Ambystoma tigrinum, following ingestion of ammonium salts (1992)
    Springer
    Journal of comparative physiology 162 (1992), S. 416-423 
    Details
    ISSN: 1432-136X
    Schlagwort(e): Acid-base balance ; Cutaneous ion exchange ; Kidney ; Ammonia ; Amphibian, Ambystoma tigrinum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The skin/gills and the kidneys of aquatic amphibians are potential sites of acid-base regulation. The roles of these organs in acid-base balance were examined in larval Ambystoma tigrinum following gastric infusion of ammonium salts. A single dose of 1.75 mEq NH4Cl·100 g-1 produced a mixed acidosis by 1 h after gavage. By 8 h after ingestion, pH and HCO 3 − had increased and PCO2 had decreased as the animals recovered. A prolonged acidosis was developed in a second group by gavage of an initial dose (1.5 mEq·100 g-1), followed by periodic maintenance doses (0.25 mEq·100 g-1) to prolong the disturbance for 8 h. The magnitude of the acidosis during this period was similar to that seen at 1 h after ingestion in the time-course study. A third group of larvae were given NaCl as a control for salt loading, which induced a small but significant respiratory acidosis. Unidirectional fluxes of Na+ and Cl- were examined during these serial ingestions. Salt loading inhibited the influx of the ingested ion. Na+ influx increased during the NH4Cl-induced acidosis. A fourth group of larvae were used to partition acid and ammonia excretion between the skin and the kidneys. These animals were given (NH4)2SO4 to allow re-examination of Cl- flux rates under non-Cl--loaded conditions. The ensuing acidosis had a reduced respiratory component and, therefore, pH did not decrease as much. Cl- influx rates did decrease significantly under these conditions. In both control and acidotic conditions, the majority of the acid efflux was as ammonia and the skin was the primary site of acid excretion. However, both the skin and the kidneys increased total acid excretion, although the efflux across the skin showed a much greater increase. This suggests a primary role for the skin in acid-base regulation in aquatic amphibians.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00258963
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  • 30
    Digitale Medien
    Digitale Medien
    Morphology of the kidney of the platypus (Ornithorhynchus anatinus: Monotremata) (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 234 (1992), S. 348-358 
    Details
    ISSN: 0003-276X
    Schlagwort(e): Morphology ; Kidney ; Urinary biology ; Ultrastructure ; Glomerulus ; Nephron ; Platypus ; Ornithorhynchus anatinus ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: The platypus kidney shows morphological similarities to those of other mammals. Macroscopically, the cortex is easily distinguishable from the fairly wide medulla. Within the medulla, no clear border is observed between the inner and outer zones. Light and transmission electron microscopically, the glomeruli show quite similar architecture to those of other mammals; however, the glomerular lobulation is very clear. The glomerular tufts are rather simple, but capillary lumen varies widely in size, which is one of the unique features of the platypus kidney. The urinary tubule is generally similar to that of human and other mammals in shape and segmentation; however, the staining specificities of histochemical reactions and the shape of epithelial cells of the Henle's loop differ from those ofother mammals. The most conspicuous features are: 1) although no protein casts are found in the tubular lumina, epithelial cells of the proximal convoluted tubule (PCT) have numerous electron-dense vesicles as in human nephrotic kidneys; and 2) the platypus Henle's loop consists of the thick epithelial cells similar to the mammalian type nephron of birds. As compared to those of other mammals such as humans and rats, our observations suggest that the platypus kidney is less developed, in terms of evolution.© Willey-Liss, Inc.
    Zusätzliches Material: 13 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ar.1092340306
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  • 31
    Digitale Medien
    Digitale Medien
    Wirkung von Aldosteron auf die Natrium-und Wasserresorption im proximalen Tubulus bei chronischer Kochsalzbelastung (1968)
    Springer
    Pflügers Archiv 300 (1968), S. 148-160 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Kidney ; Aldosterone ; Tubular Sodium Reabsorption ; Proximal Tubule ; Sodium Chloride Loading ; Niere ; Aldosteron ; tubuläre Natriumresorption ; proximaler Tubulus ; Natriumchloridbelastung
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Ratten erhielten 4 Wochen lang isotone Kochsalzlösung als Trinkflüssigkeit. Glomerulumfiltrat und Passagezeit von Lissamin-Grün im proximalen Tubulus blieben unverändert. Die spezifische Resorptionskapazität des Tubulusepithels — gemessen mit der „gespaltenen-Tropfen-Methode“ — nahm signifikant ab. Daraus ergab sich eine Verminderung der fraktionellen Natrium-und Wasserresorption im proximalen Tubulus von 51 auf 38% der gefilterten Menge. Die Na+-Ausscheidung stieg von 0,06 (Kontrollen) auf 1,25% der gefilterten Menge. Diese Veränderungen waren rückgängig zu machen durch Injektion von d-Aldosteron. Durch Bestimmung des TF/P-Inulin-Quotienten am Ende des proximalen Konvolutes wurden die Ergebnisse bestätigt. Es wird angenommen, daß die Resorptionshemmung im proximalen Tubulus bei chronischer Kochsalzbelastung durch verminderte Sekretion von Mineralocorticoiden bedingt und letzten Endes Ursache der vermehrten Na+-Ausscheidung ist. Ein Teil der proximalen Resorptionshemmung wird anscheinend in weiter distal gelegenen Nephron-Abschnitten kompensiert.
    Notizen: Summary Rats were kept on isotonic saline as drinking fluid for a period of 4 weeks. Glomerular filtration rate and proximal transit time of Lissamine green remained unchanged. The intrinsic reabsorptive capacity of the proximal tubular epithelium—measured by the “shrinking-droplet-method”—decreased significantly. As a result, fractional proximal reabsorption of sodium and water decreased from 51 to 38 per cent of the filtered load. Sodium excretion rose from 0.06 (controls) to 1,25 per cent of the filtered load. These changes were reversible by injection of d-aldosterone. The results were confirmed by measuring the TF/P ratio of inulin at the end of the proximal convolution. The results indicate that in rats chronically loaded with salt, the inhibition of fractional proximal reabsorption is due to a decreased secretion of mineralocorticoids, and is the cause of the higher sodium excretion. Apparently, the decreased proximal reabsorption is partly compensated in more distal parts of the nephron.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00362546
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  • 32
    Digitale Medien
    Digitale Medien
    Die Konzentrierfähigkeit der Säugetierniere für Elektrolyte und Harnstoff bei Variation der Plasmaharnstoffkonzentration durch ämodialyse (1968)
    Springer
    Pflügers Archiv 301 (1968), S. 259-269 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Kidney ; Concentration ; Dialysis ; Urea ; Electrolytes ; Niere ; Konzentrierung ; Dialyse ; Harnstoff ; Elektrolyte
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Um den Einfluß des Plasmaharnstoffspiegels auf die Konzentrierfähigkeit der Niere zu untersuchen, wird der Blutkreislauf von Ratten an eine Dialysiervorrichtung angeschlossen und der Harnstoffspiegel des Blutes für 3 Std durch Dialyse gegen eine harnstoffreie Spüllösung gesenkt. Gleichzeitig wird der Harnfluß der Tiere durch eine Regelanordnung konstant gehalten. Die Regelung wird dadurch erreicht, daß dem Blutkreislauf bei zu hohem Harnfluß automatisch Flüssigkeit entzogen und bei zu niedrigem Harnfluß Flüssigkeit zugeführt wird. Es wird gefunden, daß die Harnstoffkonzentrationen im Harn linear mit dem Plasmaharnstoffspiegel abfallen bzw. ansteigen. Die Summe der Elektrolytkonzentrationen fällt dagegen mit dem Plasmaharnstoffspiegel nur wenig ab. Falls ein völliger Harnstoffentzug möglich wäre, würde auch dann noch eine Konzentrierung der Elektrolyte auf mehr als doppelt isoton möglich sein. Die Ergebnisse der Untersuchung lassen sich am einfachsten mit der Annahme interpretieren, daß in der Niere der Ratte zwei unterschiedlich arbeitende Konzentrierungsmechanismen wirksam sind, von denen der eine im wesentlichen Elektrolyte, der andere im wesentlichen Harnstoff konzentriert. Der Konzentrierungsmechanismus für Elektrolyte könnte im äußeren Mark, der für Harnstoff im inneren Mark lokalisiert sein.
    Notizen: Summary To investigate the influence of plasma urea levels on the concentrating power of the kidney, the blood circulation of rats was connected to a dialyser; with dialysis against a urea-free cleaning solution, the urea level of the blood was lowered for three hours. During this, the urine flow of the animals was kept constant by a regulating arrangement. This control was achieved by removing fluid from the blood circulation in the case of too high urine flow and by putting in fluid in the case of too low urine flow. It was found that the concentration of urea in the urine had a direct linear relationship with the plasma urea level. The total electrolyte concentration fell only slightly compared to the plasma urea level falls. If the urea could have been completely removed, high concentrating of the electrolyte, to more than double isotonic, would still have been possible. The simplest way to interpret the results of this research is by the hypothesis that two different concentrating mechanisms are at work in the rat kidney, the one essentially concentrating electrolytes, and the other principally urea. The concentrating mechanism for electrolytes could be localised in the outer medulla, and for urea in the inner medulla.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00363773
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  • 33
    Digitale Medien
    Digitale Medien
    Die Harnstoff- und Elektrolytkonzentrationen im Nierenmarkgewebe nach zweitägiger Infusion hypertoner Harnstoff- und NaCl-Lösungen (1968)
    Springer
    Pflügers Archiv 301 (1968), S. 270-279 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Kidney ; Concentration ; Infusion ; Urea ; Electrolytes ; Niere ; Konzentrierung ; Infusion ; Harnstoff ; Elektrolyte
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Um die gegenseitige Beeinflussung von Harnstoff und NaCl bei der Bildung eines konzentrierten Harns zu untersuchen, werden Ratten 2 Tage lang NaCl-Lösungen mit wechselndem Harnstoffgehalt infundiert. Sodann werden der Harn sowie das Gewebe der Nierenrinde, des äußeren Marks und des inneren Marks auf ihren Gehalt an Kalium, Natrium und Harnstoff analysiert. Es wird gefunden, daß die Konzentrierfähigkeit der Rattenniere unter diesen Versuchsbedingungen für NaCl bei gleichzeitiger Zufuhr von Harnstoff geringer wird. In der Niere steigen NaCl und Harnstoffkonzentrationen unter allen Infusionsbedingungen von der Nierenrinde zur Nierenpapille hin an. Bei Infusion reiner NaCl-Lösungen entsprechen die NaCl- und Harnstoffkonzentrationen im Harn denen in der Papille. Bei Infusion von harnstoffhaltigen NaCl-Lösungen sind im Harn die NaCl-Konzentrationen höher und die Harnstoffkonzentrationen niedriger als im Papillengewebe. Diese Ergebnisse schließen aus, daß die hohen Harnstoffkonzentrationen im Nierenmarkgewebe durch einfache Diffusion des Harnstoffes aus den Sammelrohren in das Nierenmarkgewebe zustande kommen. Es wird die Möglichkeit diskutiert, daß die Harnstoffkonzentrierung unter den hier wiedergegebenen Versuchsbedingungen durch Gegenstromdiffusion in dem Vasa recta-System verursacht wird. Der Konzentriereffekt hierfür könnte durch einen Wasserfluß aufgrund osmotischer Kräfte von dem Blutgefäßsystem in die Henleschen Schleifen zustande kommen, wenn der Harn in den Henleschen Schleifen durch Aufnahme von NaCl, das aus den Sammelrohren stammt, hyperton wird.
    Notizen: Summary To investigate the mutual interdependence of urea and sodium in producing concentrated urine, solutions of different concentrations of sodium and urea were infused into the stomach of rats. After two days' infusion, the urine and tissues from the different zones of the kidneys were analysed for sodium, potassium and urea content. It was found that the efficiency of the rat kidney in producing urine with high sodium content was diminished if urea was infused together with the sodium chloride. Under all conditions sodium and urea concentrations increased from the cortex to the papilla of the kidneys. When pure sodium chloride solutions were infused, sodium and urea concentrations in the urine were nearly equal to the corresponding concentrations in the papilla. Infusion of solutions containing NaCl and urea caused production of urine with a higher sodium concentration and lower urea concentration than in the papilla. These results show that the high concentration of urea in the medulla of the kidney does not arise by passives diffusion of urea from the collecting ducts into the medullary tissue. The possibility that the concentration of urea in the inner medulla is produced by counter current diffusion of urea in the vasa recta is discussed. The concentration effect necessary for this counter current multiplication could be created by an osmotic flow of water from the vasa recta into loops of Henle, if the urine in the loops becomes hypertonic by taking up sodium chloride from the collecting ducts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00363774
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  • 34
    Digitale Medien
    Digitale Medien
    Licht-und elektronenmikroskopische Untersuchungen am proximalen Tubuluskonvolut der Rattenniere nach intraluminaler Ölinjektion (1968)
    Springer
    Pflügers Archiv 302 (1968), S. 149-165 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Tubules ; Kidney ; Intraluminal Oil Injection ; Ultrastructure of Kidney ; Proximales Tubuluskonvolut ; Rattenniere ; intraluminale Ölinjektion ; Ultrastruktur der Niere
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Light- and electronmicroscopic evaluation of proximal convolutions of the rat kidney were made following injection with either mineral oil or castor oil. The following observations were made: 1. Injection of mineral oil does not result in a complete blockade of the tubular lumen and leads to morphological lesions of epithelial cells. 2. Injection of the more viscous castor oil, in contrast, leads to a dilatation of the tubular lumen and a compression of the brush border of proximal tubular cells. Thus a better blockade of longitudinal flow is achieved. A toxic effect of castor oil on the tubular epithelium could not be detected. Mechanical lesions, similar to those observed after mineral oil injection, were less frequent. They consisted in a penetration of oil into the cells, perhaps as consequence of the tubular dilatation. 3. In oil-injected proximal tubular segments the following cytologic phenomena were observed: a) a cessation of the normal pinocytosis, which is induced in the presence of tubular fluid, b) simultaneously the “large resorption vacuoles” disappear, indicating that they originate from confluence of pinocytotic vesicles, c) in dilated tubules protein resorption vacuoles are found to have ruptured towards the tubular lumen suggesting a high hydrostatic pressure within the vacuoles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00586867
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  • 35
    Digitale Medien
    Digitale Medien
    Natrium- und Wasserresorption in den verschiedenen Abschnitten des Nephrons beim experimentellen renalen Hochdruck der Ratte (1968)
    Springer
    Pflügers Archiv 304 (1968), S. 322-335 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Kidney ; Experimental Hypertension ; Tubular Sodium Reabsorption ; Tubular Water Reabsorption ; Henle's Loop ; Niere ; experimenteller Hochdruck ; tubuläre Natriumresorption ; tubuläre Wasserresorption ; Henlesche Schleife
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung 4 Wochen nach Klammerung einer Nierenarterie war der Perfusionsdruck der geklammerten Niere normal, während der arterielle Mitteldruck auf 188 mm Hg angestiegen war. Die Ausscheidung von Natrium und Wasser im Harn der geklammerten Niere war normal, im Harn der ungeklammerten Niere erheblich höher als normal. Glomerulumfiltrat (pro g Niere), intratubulärer Druck, Tubulusweite, Passagezeit von Lissamingrün und die fraktionelle Resorption von Natrium und Wasser waren im proximalen Tubulus sowohl in der geklammerten wie in der ungeklammerten Niere normal. In der ungeklammerten Niere war die Passagezeit durch die Henlesche Schleife stark verkürzt und die Resorption von Natrium und Wasser in der Schleife erheblich vermindert. Diese Veränderungen — obwohl zum Teil kompensiert durch vermehrte Resorption im distalen Tubulus und im Sammelrohr — sind verantwortlich für die höhere Wasser- und Natriumausscheidung der ungeklammerten Niere. Die Ursache ist wahrscheinlich eine stärkere Durchblutung des Nierenmarkes. Im Nephron der geklammerten Niere war die fraktionelle Natrium- und Wasserresorption nicht signifikant von normalen Werten verschieden mit der Ausnahme einer niedrigeren Natriumresorption im distalen Tubulus und einer höheren Natriumresorption im Sammelrohr. Der Natrium-Transport im distalen Tubulus ist anscheinend gestört; TF/P−Na+ betrug im Mittel 0,6 bis zum Ende des distalen Tubulus. Die Ergebnisse können die unterschiedliche Harnausscheidung erklären, die beim Hypertoniker mit einseitiger Nierenarterienstenose beobachtet wird (Howard-Test).
    Notizen: Summary Four weeks after clamping one renal artery, the perfusion pressure of the clamped kidney was normal whereas the mean arterial pressure had increased to 188 mm Hg. Urinary excretion of sodium and water of the clamped kidney had not changed while that of the untouched kidney increased considerably. Glomerular filtration rate (per g kidney), intratubular pressure, tubular diameter, transit time of Lissamine green and fractional sodium and water reabsorption of the proximal tubule were normal in both the clamped and the untouched kidney. In the untouched kidney, the transit time through Henle's loop was shortened and the sodium and water reabsorption in it was significantly reduced. These changes, although partly compensated by higher reabsorption in the distal tubule and collecting duct, are responsible for the increased sodium and water excretion of the untouched kidney. They are probably due to an increased medullary blood flow. In the clamped kidney, fractional sodium and water reabsorption of the whole nephron did not differ significantly from normal values. However, sodium reabsorption was lower in the distal tubule and higher in the collecting duct. Sodium transport in the distal tubule seemed to be impaired; throughout its length sodium TF/P ratio averaged 0.6. These results may explain the different urinary excretion found in human hypertension following unilateral renal artery stenosis (Howard-Test).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00587708
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  • 36
    Digitale Medien
    Digitale Medien
    Tubuläre Wasser- und Substanzbewegungen infolge artifizieller transcellulärer osmotischer Gradienten bei Rana ridibunda (1968)
    Springer
    Pflügers Archiv 303 (1968), S. 249-261 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Kidney ; Fluxes ; Osmotic Gradients ; Niere ; Flüssigkeits-Substanzbewegungen ; osmotische Gradienten
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Durch artifizielle osmotische Druckdifferenzen von 150 mOsmol/l zwischen Lumen- und Blutseite der Tubulusepithelien von Rana ridibunda wird Flüssigkeit im Richtungssinne der Reabsorption oder — in geringerem Maße — der Sekretion längs des osmotischen Gradienten bewegt. Na+ wird in jedem Fall „trocken” reabsorbiert. Bei mit Furosemid blockiertem aktiven Na+-Transport läuft isoton Flüssigkeit längs des osmotischen Gradienten aus dem Tubuluslumen in das blutseitige Medium. Bei umgekehrt gerichtetem Gradienten wird das Filtrat so verändert, als ob es durch Einstrom reinen Wassers verdünnt würde. Die Tubulusepithelien verhalten sich so, als besäßen sie — im Zustand des blockierten aktiven Na+-Transportes — ein „Rückschlagventil” für Na+. Wenn der osmotische Gradient so gerichtet ist, daß Wasser oder Flüssigkeit aus dem Lumen in das blutseitige Medium läuft, dann kommt es bei umgekehrt gerichtetem Na+-Konzentrationsgradienten nicht zum Einstrom von Na+ in das Tubuluslumen. Die Na+-Harnkonzentration sinkt beträchtlich unter die des Perfusates, was als Ausdruck einer Na+-Reabsorption gegen den Konzentrationsgradienten gedeutet wird. Bei Blockierung des Na+-Transportes durch Furosemid kommt es wiederum zum Einstrom reinen Wassers in die Tubuluslumina. Die Versuche mit durch Furosemid blockiertem Na+-Transportmechanismus sind beweisend, daß die Tubuli für Na+ im Richtungssinne der Sekretion impermeabel sind. Die „Verdünnung” des Tubulusinhaltes durch einen osmotischen Gradienten, der Wasser in die Tubuli hineinlaufen läßt, kommt also nicht durch ein Überwiegen der Reabsorption über die „Sekretion” zustande. Wird statt des leicht penetrierenden Na-Chlorids das schwer penetrierende Natriumcyclohexansulfamat angeboten, dann wird absolut gegenüber den Versuchen mit Na-Chlorid weniger Na+ transportiert. Im übrigen zeigen die Nieren jedoch das gleiche Verhalten wie bei Angebot von Na-Chlorid.
    Notizen: Summary Osmotic gradients of 150 mosmol/l between intratubular fluid and blood in the kidney of Rana ridibunda induce a fluid movement down the osmotic gradient which is stronger into the tubule than out of it. In either case Na+ is reabsorbed “dry”. If the active Na+-transport is blocked by Furosemid an osmotically downhill movement of isotonic fluid out of the tubule obtains. Reversal of the osmotic gradient induces a reversal of flow but the inward moving fluid is diluted. The tubular cells seem to inhibit the backwash of Na+. If the osmotic gradient induces an outflow of fluid out of the tubule no influx of Na+ occurs even in the presence of a concentration gradient for Na+ in the opposite direction. The Na+-concentration in the urine falls considerably below that of the perfusion fluid. This finding indicates Na+-reabsorption against a concentration gradient. Upon blocking of the Na+-transport by Furosemid water enters the tubules. The results of the experiments in which the Na+-transport was blocked by Furosemid prove that the tubules are impermeable for Na+ in the direction of secretion. The “dilution” of the tubular fluid as a result of an osmotic gradient which induces an influx of water isnot due to a reabsorption outbalancing “secretion”. If instead of the easily penetrating NaCl the slowly penetrating Na+-cyclohexanesulphamate is used, less Na+ is transported. However, in every other respect the results obtained are similar to those described above.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01890904
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  • 37
    Digitale Medien
    Digitale Medien
    Mikropunktionsuntersuchung am distalen Tubulus beim Goldblatt-Hochdruck der Ratte (1968)
    Springer
    Pflügers Archiv 304 (1968), S. 336-350 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Kidney ; Experimental Hypertension ; Distal Tubular Sodium Reabsorption ; Distal Osmolality ; Tubular Potassium Secretion ; Niere ; experimenteller Hochdruck ; distale Natrium resorption ; distale Osmolalität ; tubuläre Kaliumsekretion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Vier Wochen nach Klammerung einer Nierenarterie wurde die Funktion des distalen Tubulus untersucht. In der ungeklammerten, unter dem hohen Blutdruck stehenden Niere blieb die Tubulusflüssigkeit bis 90% distaler Tubuluslänge hypoton. Dies wird auf eine erhöhten Flüssigkeitseinstrom aus der Henleschen Schleife zurückgeführt; eine verminderte Wasserpermeabilität des distalen Tubulus konnte nicht nachgewiesen werden. In der geklammerten Niere war mit Ausnahme des frühdistalen Abschnittes die Natriumkonzentration on jeder Stelle des distalen Konvolutes signifikant höher als in der ungeklammerten Niere und in Kontrollnieren. Auch fehlte im distalen Tubulus der geklammerten Niere eine Nettokaliumsekretion. die distale Gleichgewichtskonzentration für Natrium war auf der geklammerten Seite erhöht, auf der ungeklammerten Seite normal. Der isotone Natriumausstrom (Methode des gespaltenen Tropfens) war in der geklammerten Niere vermindert, in der ungeklammerten Niere erhöht. Die frühdistale Harnstoffkonzentration war in der ungeklammerten Niere gegenüber der geklammerten Niere und Nieren von Kontrollratten erniedrigt. Spätdistal war TF/P-Harnstoff in beiden Nieren gleich. Beide Nieren hatten ein normales Glomerulumfiltrat und normale tubuläre Passagezeiten mit Ausnahme einer verkürzten Schleifenzeit in der ungeklammerten Niere. Die Befunde werden dahingehend interpretiert, daß der aktive Natriumtransport im distalen Tubulus der beiden Nieren voneinander verschieden ist, möglicherweise infolge des unterschiedlichen Reningehaltes der beiden Nieren.
    Notizen: Summary Four weeks after constricting one renal artery distal tubular function was studied using the micropuncture technique. In the untouched kidney tubular fluid remained hypotonic up to 90% distal tubular length. We believe this to be the result of the high inflow of tubular fluid from Henle's loop. A reduced permeability for water could not be demonstrated. Except for the early part of the distal tubule there was a marked increase in sodium concentration in the clamped kidney as compared to values obtained in the untouched one and in kindneys of control animals. In addition no potassium secretion could be observed in the clamped kidney. The distal steadystate concentration for sodium was increased in the clamped kidney and normal in the untouched one. Reabsorptive half-time, measured by the split droplet technique, was prolonged in the clamped kidney and shortened in the untouched one. Early distal urea concentration was lower in the untouched kidney than in the clamped one and in control kidneys, while at the end of the distal tubule urea concentrations did not differ significantly. Both kidneys had normal glomerular filtration rates and proximal tubular transit times, whereas a shortened transit time through Henle's loop of the untouched kidney was found. The results indicate that active sodium transport in the distal tubule of the clamped kidney differs from that of the untouched one, possibly due to the different renin concentration in both kidneys.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00587709
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  • 38
    Digitale Medien
    Digitale Medien
    Passage of plasma through the kidney studied by external counting and autoradiography (1968)
    Springer
    Pflügers Archiv 305 (1968), S. 96-104 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Blood Circulation Time ; Kidney ; Plasma ; Radioautography ; Radioisotope Dilution Technique ; Regional Blood Flow ; Mittlere Kreislaufzeit ; Niere ; Plasma ; Autoradiographie ; Isotopenverdünnungstechnik ; Regionale Nierendurchblutung
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary At different times after injection into the renal artery of131I-albumin, the distribution of the tracer in kidneys of the rabbit and the dog was illustrated by a series of autoradiograms. In order to determine the mean circulation time for albumin in the kidney, the radioactivity over the kidney was simultaneously registered by external monitoring. A short mean circulation time was measured for albumin (plasma) passing cortex, and a longer one for that fraction of the albumin that passed through medulla, papillae, and capsule. The investigation rendered probable that the mean circulation time for blood through the kidney determined by the external technique applies to blood passing cortex. The circulation times for blood through medulla, papillae, and capsule are not included in the calculation of the mean circulation time.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00586398
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  • 39
    Digitale Medien
    Digitale Medien
    Beziehung zwischen chronisch-toxischer Knochenschädigung und Fremdmetallbindung an Serum-Proteine (1968)
    Springer
    Archives of toxicology 23 (1968), S. 245-249 
    Details
    ISSN: 1432-0738
    Schlagwort(e): Bone ; Strontium poisoning ; Parathormone ; Kidney ; Knochen ; Strontiumvergiftung ; Parathormon ; Niere
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Restitution des strontiumgeschädigten Skelets wachsender Sprague Dawley Ratten ist von einem Anstieg der dialysablen Strontium- und Calciumfraktion des Serums begleitet. Die Ergebnisse legen eine Beeinflussung der renalen Manipulation von Kationen bei Knochenschädigungen durch Fremdmetalle nahe.
    Notizen: Summary Restitution of skeletal damage caused by strontium in growing Sprague Dawley rats is accompanied by an increase in the dialysable serum fractions of strontium and calcium. The results suggest that the renal manipulation of cations is influenced in bone lesions caused by foreign metals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00577404
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  • 40
    Digitale Medien
    Digitale Medien
    Zum extrahepatischen Stoffwechsel von Aldosteron (1968)
    Springer
    Clinical and experimental medicine 145 (1968), S. 270-277 
    Details
    ISSN: 1591-9528
    Schlagwort(e): Aldosterone ; Kidney ; Stop flow dog ; Aldosteron ; Niere ; Stop flow-Hund
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Mit Stop flow-Versuchen an Hunden konnten wir nach Infusion von 1,2-3H-18-Aldosteronglucuronid im Gegensatz zur Infusion von freiem 1,2-3H-Aldosteron keine proximale Sekretion von 1,2-3H-18-Aldosteronglucuronid nachweisen. Daraus kann geschlossen werden, daß in Hundenieren die proximalen Tubuluszellen wohl 18-Aldosteronglucuronid aus Aldosteron bilden und an das Tubuluslumen abgeben, während im Nierenarterienblut vorhandenes 18-Aldosteronglucuronid nur glomerulär filtriert und ausgeschieden wird.
    Notizen: Summary In stop flow experiments during infusion of 1,2-3H-18-aldosterone glucuronide there was no proximal tubular secretion of this metabolite in contrary to experiments during infusion of 1,2-3H-aldosterone. The discrepancy must be explained by formation of 1,2-3H-aldosterone glucuronide out of3H-aldosterone in proximal tubular cells, while the 1,2-3H-18-aldosterone glucuronide in the plasma of the renal artery blood is only filtered in the glomerulum.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02044618
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  • 41
    Digitale Medien
    Digitale Medien
    Zum extrahepatischen Stoffwechsel von Aldosteron (1968)
    Springer
    Clinical and experimental medicine 146 (1968), S. 336-345 
    Details
    ISSN: 1591-9528
    Schlagwort(e): Aldosterone ; Kidney ; Man ; Aldosteron ; Niere ; Mensch
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Auf Grund eines Vergleiches der Verhältnisse von 1,2-3HTetrahydroaldosteronglucuronid zu 1,2-3H-18-Aldosteronglucuronid im Plasma von drei Normalpersonen und zwei nephrektomierten Patienten nach einer Injektion von 1,2-3H-Aldosteron haben wir folgende Schlüsse in Betracht gezogen: 1. Das im Blutplasma vorhandene 1,2-3H-18-Aldosteronglucuronid wird nur glomerular filtriert. 2. Die renale Clearance von 18-Aldosteronglucuronid, die etwa das Fünffache der Inulinclearance beträgt [13, 15], mu\ zu vier Fünfteln auf Bildung von 18-Aldosteronglucuronid durch die proximalen [15] Tubuluszellen zurückgeführt werden. 3. Das Ausma\ der renalen Bildung von 18-Aldosteronglucuronid liegt in einer Grö\enordnung von 80% der Gesamtmenge 18-Aldosteronglucuronid im 24 StdUrin.
    Notizen: Summary After an intravenous injection of 1,2-3H-aldosterone the ratios of 1,23H-tetrahydroaldosterone glucuronide to 1,2-3H-aldosterone glucuronide in the blood plasma of three normal and two nephrectomized persons were compared. In the three normal persons the ratios were of the same magnitude as in the two nephrectomized persons. On the basis of glomerular filtration of tetrahydroaldosterone glucuronide, as previously demonstrated by renal clearance studies in man [13, 15] and stop flow experiments in dogs [6], we made the following deductions: 1. 18aldosterone glucuronide in blood plasma is only filtered in the glomerulum. 2. The renal clearance of 18-aldosterone glucuronide, as investigated during aldosterone infusion in man [13, 15], therefore must be explained by glomerular filtration of only one fifth and by formation of four fifth of 18-aldosterone glucuronide by proximal [15] tubular cells. 3. This means that about 80% of 18-aldosterone glucuronide excreted in urine is formed by the kidneys.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02045932
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  • 42
    Digitale Medien
    Digitale Medien
    Die arteriovenösen Differenzen der gesamten und der einzelnen freien Fettsäuren am Herzen, am Skeletmuskel und an der Niere bei verschieden hoher arterieller Konzentration (1968)
    Springer
    Clinical and experimental medicine 146 (1968), S. 67-82 
    Details
    ISSN: 1591-9528
    Schlagwort(e): Plasma FFA composition ; Individual FFA extraction in heart ; Skeletal muscle ; Kidney ; Plasma-FFS-Zusammensetzung ; Extraktion der Einzel-FFS in Herz ; Skeletmuskel ; Niere
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei narkotisierten Hunden wurden die arteriovenösen Differenzen der gesamten und der einzelnen freien Fettsäuren (FFS) am Herzen, am elektrisch stimulierten Skeletmuskel (M. gastrocnemius) und an der Niere bei verschieden hoher arterieller FFS-Konzentration untersucht. Die Konzentration der gesamten FFS wurde titrimetrisch, ihre Zusammensetzung wurde gaschromatographisch bestimmt. Bei einer Steigerung der FFS-Konzentration durch Noradrenalininfusionen stiegen die Anteile der öl- und der Palmitinsäure an, und die Anteile der Stearin- und der Linolsäure sanken ab. Bei einer Senkung der FFS-Konzentration durch Glucoseinfusionen nahmen die Anteile der öl- und der Palmitoleinsäure ab, und die Anteile der Palmitin- und der Stearinsäure nahmen zu. Unter Kontrollbedingungen entfielen am Herzen 44% der gesamten FFS-Extraktion auf die öl- und 24% auf die Palmitinsäure, am Skeletmuskel entfielen 43% auf die öl- und 29% auf die Palmitinsäure. Bei einer Steigerung der arteriellen FFS-Konzentration durch Noradrenalin extrahierten Herz- und Skeletmuskel nur noch öl-, Palmitin- und Palmitoleinsäure. Gleichzeitig wurde im Herz Stearin- und Linolsäure und im Skeletmuskel Stearinsäure produziert. In der Niere entfielen unter Kontrollbedingungen je 40% der Gesamt-FFS-Extraktion auf die Palmitin- und die ölsäure. Es wird gefolgert, daß die öl-, die Palmitin- und die Palmitoleinsäure gegenüber den anderen FFS bevorzugt als Energiequellen benutzt werden, weil bei gleicher arterieller Konzentration höhere Extraktionen für diese drei FFS gemessen wurden. Noradrenalin bewirkt, wahrscheinlich durch Aktivierung von Lipase, im Herzen und im arbeitenden Skeletmuskel einen Abbau von gespeicherten oder im Plasma transportierten Triglyceriden.
    Notizen: Summary The arteriovenous differences of total and individual free fatty acids (FFA) have been determined in the myocardium, in the electrically stimulated skeletal muscle (gastrocnemius) and in the kidney of closed chest anesthetized dogs. The concentration of total FFA was determined by titration, their composition was determined by gaschromatography. When the arterial concentration of total FFA was increased by norepinephrine infusions the percentage of olic and of palmitic acid increased and the percentage of stearic and linolic acid decreased. When the concentration of total FFA was decreased by glucose infusions the percentage of olic and palmitolic acid decreased and the percentage of palmitic and stearic acid increased. Under control conditions in the myocardium 44% of the total FFA extraction were related to olic and 24% to palmitic acid and in the skeletal muscle 43% were related to olic and 29% to palmitic acid. During norepinephrine induced increases of arterial FFA concentration myocardium and skeletal muscle extracted only olic, palmitic and palmitolic acid. At the same time in the myocardium stearic and linolic acid and in the skeletal muscle stearic acid was produced. In the kidney under control conditions 40% of the total FFA extraction were related to palmitic and 40% to olic acid. Since the extraction of olic, palmitic and palmitolic acid was higher than the extraction of other FFA at comparable arterial concentrations, it is concluded, that these three FFA are used in preference to other FFA as energy sources. Norepinephrine causes, probably via activation of lipase, in the myocardium and in the working skeletal muscle a breakdown of stored or in plasma transported triglycerides.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02048475
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