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  • 1965-1969  (26)
  • 1968  (26)
  • Psychopharmacology  (14)
  • Kidney  (12)
  • 1
    ISSN: 1432-2072
    Keywords: Benzodiazepines ; Psychopharmacology ; Antianxiety ; Drug Tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Oxazepam has two opposing actions on behavior: a responsedecreasing or depressant action and a response-increasing or disinhibitory action. The course of the two actions in chronic dosing was determined in rats in a test in which punished and unpunished schedules of reinforcement were alternated. The depressant action (measured by a decrease in the rate of unpunished behavior) was observed to undergo tolerance after 3–4 doses, while the disinhibitory action (measured by an increase in the rate of punished behavior) failed to show tolerance and even increased throughout the chronic series. The selective tolerance of the depressant action is probably due to neuronal adaptation, but changes in metabolism also may be involved. The increase in the rate of punished behavior is attributed, at least in part, to a progressive unmasking of the disinhibitory action as tolerance to the depressive action develops.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 13 (1968), S. 118-128 
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Diagnosis ; Sampling Studies ; Statistics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Theoretical models for sample selection by diagnosis using one, one-out-of-two, two, two-out-of-three, and three concurring opinions are illustrated. These models are then applied to two categories, schizophrenia and depressive disorders, for an actual sample of patients diagnosed by multiple observers. The conclusion is reached that sample selection by a single opinion is not sufficiently reliable for research studies. The choice of alternative methods of selection depends on the needs of a particular study. Samples chosen on the basis of two-out-of-three concurring opinions provide the least total error. When erroneous inclusions are particularly undesirable, higher degrees of consensus—e.g. agreeing pairs or triplets—are necessary.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 13 (1968), S. 129-139 
    ISSN: 1432-2072
    Keywords: Electroencephalography ; Psychopharmacology ; Imipramine ; Amphetamine ; Physostigmine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The results of the interaction of imipramine, physostigmine and d/l amphetamine in various intravenously administered dosages were studied on the cortical and subcortical electrical activity of cats. Imipramine was shown to cause a cortical synchronization, hippocampal desynchronization, rise in the threshold of electrocortical arousal and limbic convulsive activity which was potentiated by amphetamine. Imipramine increased the amount of physostigmine, but decreased the amount of amphetamine needed for cortical desynchronization. The possible significance of these findings for the neuropsychopharmacological action of imipramine is briefly discussed.
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  • 4
    ISSN: 1432-2072
    Keywords: Indoleamine Metabolism ; Psychopharmacology ; Antidepressive Drugs ; Amphetamine Derivatives (Chlorinated) ; Depression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary CMA (p-chloro-N-methylamphetamine) lowers the cerebral 5-HT concentration in test animals but has virtually no effect on the catecholamine concentrations. Moreover, this compound was found to behave in depressive patients like an antidepressive drug, not like a central stimulant of the amphetmine type. The study described was conducted in order to establish whether CMA influences the overall metabolism of indoleamines in man. Such an influence was clearly demonstrable. Our findings are consistent with the hypothesis that CMA releases 5-HT from its depots. It has not been explained why a considerable proportion of the released 5-HT is excreted unchanged and why the increase in 5-HIAA excretion is so small: the overall activity of MAO was found not to be inhibited. No indications of abnormal 5-HT degradation were found at this time. Patients with vital depressions who improved on CMA medication showed a lower 5-HIAA excretion before treatment than did patients who were refractory to CMA treatment. This is consistent with earlier observations. The possible cause of this phenomenon is discussed. Among the various possibilities considered, an abnormal 5-HT metabolism is regarded as the most plausible. Pertinent investigations are being continued.
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  • 5
    ISSN: 1432-2013
    Keywords: Kidney ; Aldosterone ; Tubular Sodium Reabsorption ; Proximal Tubule ; Sodium Chloride Loading ; Niere ; Aldosteron ; tubuläre Natriumresorption ; proximaler Tubulus ; Natriumchloridbelastung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 6
    ISSN: 1432-2013
    Keywords: Kidney ; Concentration ; Dialysis ; Urea ; Electrolytes ; Niere ; Konzentrierung ; Dialyse ; Harnstoff ; Elektrolyte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 7
    ISSN: 1432-2013
    Keywords: Kidney ; Concentration ; Infusion ; Urea ; Electrolytes ; Niere ; Konzentrierung ; Infusion ; Harnstoff ; Elektrolyte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 8
    ISSN: 1432-2013
    Keywords: Tubules ; Kidney ; Intraluminal Oil Injection ; Ultrastructure of Kidney ; Proximales Tubuluskonvolut ; Rattenniere ; intraluminale Ölinjektion ; Ultrastruktur der Niere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
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  • 9
    ISSN: 1432-2013
    Keywords: Kidney ; Experimental Hypertension ; Tubular Sodium Reabsorption ; Tubular Water Reabsorption ; Henle's Loop ; Niere ; experimenteller Hochdruck ; tubuläre Natriumresorption ; tubuläre Wasserresorption ; Henlesche Schleife
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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).
    Notes: 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).
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  • 10
    ISSN: 1432-2013
    Keywords: Kidney ; Fluxes ; Osmotic Gradients ; Niere ; Flüssigkeits-Substanzbewegungen ; osmotische Gradienten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 304 (1968), S. 336-350 
    ISSN: 1432-2013
    Keywords: Kidney ; Experimental Hypertension ; Distal Tubular Sodium Reabsorption ; Distal Osmolality ; Tubular Potassium Secretion ; Niere ; experimenteller Hochdruck ; distale Natrium resorption ; distale Osmolalität ; tubuläre Kaliumsekretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 12
    Electronic Resource
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    Springer
    Pflügers Archiv 305 (1968), S. 96-104 
    ISSN: 1432-2013
    Keywords: Blood Circulation Time ; Kidney ; Plasma ; Radioautography ; Radioisotope Dilution Technique ; Regional Blood Flow ; Mittlere Kreislaufzeit ; Niere ; Plasma ; Autoradiographie ; Isotopenverdünnungstechnik ; Regionale Nierendurchblutung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
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  • 13
    Electronic Resource
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    Archives of toxicology 23 (1968), S. 245-249 
    ISSN: 1432-0738
    Keywords: Bone ; Strontium poisoning ; Parathormone ; Kidney ; Knochen ; Strontiumvergiftung ; Parathormon ; Niere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 14
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    Psychopharmacology 12 (1968), S. 384-399 
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Tranquilizing Agents ; Chlordiazepoxide ; Frustration ; Animal Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This experiment investigated the possibility that chlordiazepoxide (CDP) has unique properties that account for state dependent learning, and prevention of conflict-induced behavior fixations. One group of rats were given a discrimination problem on a Lashley jumping stand, but on even days all responses were punished. Another group were treated the same way except than on even days all responses were rewarded. Each of these groups were subdivided, half of the Ss were given CDP on even days, the other half no drug. The results showed that punishment on even days for the response to be learned disrupted learning more than reward for responses that were to be avoided. CDP practically eliminated these disruptive effects and aided learning for the punishment group, but led to a slower rate of learning for the reward group. These findings confirmed the hypothesis that CDP attenuates the effects of negative incentives, and that this property accounts for the drug's cue value in discrimination learning and for its fixation prevention characteristics.
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  • 15
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    Psychopharmacology 12 (1968), S. 371-383 
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Cholinergic Blocking Drugs ; Animal Behavior ; Scopolamine ; Conditioned Reflex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Atropine or scopolamine improved conditioned avoidance behavior for most rats which performed poorly, in spite of extensive training, in a shuttle-box procedure. As previously reported, d-amphetamine also improved performance in many of these animals, but there was no particular relationship between a rat's responses to the cholinergic blocking agents and to d-amphetamine. The effect of any one of the 3 agents was, for the most part, reversible after the drug effect had dissipated. Physostigmine was quite potent in disrupting avoidance behavior in rats that performed well in the shuttle-box, even in animals that were overtrained. This impairment was antagonized by atropine or scopolamine, partly antagonized by d-amphetamine, and not antagonized by methyl atropine. Poor performers were found to be very sensitive to the disruptive effects of physostigmine, losing much of their escape behavior after relatively small doses. The results are interpreted as evidence for a central cholinergic system with inhibitory influences for modulating stimulus-response patterns. Under normal circumstances this inhibitory system probably functions in an integrated manner with the adrenergic mobilizing system for the central control of learned behavior. Centrally-active anticholinergic drugs of the muscarinic type appear to influence behavioral responses by inducing a response disinhibition.
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  • 16
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Electrophysiology ; Arousal ; Animal Behavior ; Brain Biogenic Amines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have studied the interactions of reserpine and the monoamine oxidase inhibitors, nialamide and isocarboxazid, in rabbits. EEG recordings were made from animals with acute and chronically implanted electrodes. Gross behavioral observations were made in freely moving rabbits and brain amine concentrations of norepinephrine and serotonin were also determined. Emphasis was placed on observing drug effects over periods of time ranging up to 13 days. Rabbits given isocarboxazid or nialamide alone exhibit a phenomenon rarely seen in the control animals, namely partial activation, an EEG pattern in which slow waves of high amplitude are maintained in the cortex while fast activity appears in subcortical structures. This effect was also observed in rabbits treated with nialamide and reserpine in combination. By appropriate dosage schedules in which reserpine was administered to animals pretreated with monoamine oxidase inhibitors it was possible to maintain extended periods of frank arousal or EEG activation over a period of several days. The absolute concentrations of brain amines bore little or no relationship to the EEG effects observed, however, increased ratios of serotonin to norepinephrine were observed in conjunction with EEG activation and signs of behavioral excitement.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 12 (1968), S. 414-423 
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Barbiturates ; Phenothiazines ; Animal Behavior ; Motor Coordination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The rotarod test of motor coordination in mice was modified by increasing the rotation speed every 30 sec until the animals fell off. This procedure yielded a stable, proficient level of performance within four brief trials; the approximately normal distribution of performance times provided an equivalent measure of either improvement or impairment caused by drugs and permitted the use of parametric statistical tests. A total of 240 mice were assigned to 20 different groups of 12 each, administered oral doses of placebo or different drugs, prior to trial 4. The use of a ratio score (performance time in trial 4 divided by the same animal's time in trial 3) provided a measure of drug-induced changes, controlling for individual differences among animals in over-all level of performance. Two phenothiazines (chlorpromazine and perphenazine) impaired performance at low doses, with a progressively greater decrement at increasing doses (4, 8, 16 mg/kg); 2 barbiturates (pentobarbital and amobarbital) showed an all-or-none effect, with no significant decrement at the lower doses (20 and 40 mg/kg) but almost complete incapacitation at the highest dose of 80 mg/kg. Performance superior to the placebo condition was found with the 2 lower doses of pentobarbital and with 3 d-amphet-amine doses (4, 8, 16 mg/kg). An analysis of individual differences gave evidence that the animals which were inferior in prior performance were more susceptible to both improvement and impairment of performance under the influence of drugs.
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  • 18
    ISSN: 1432-2072
    Keywords: Central Nervous System ; Psychopharmacology ; DDT ; Parathion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The offspring of female mice treated with 2.5 mg/kg DDT during the second or third trimester of pregnancy showed a delayed acquisition of the conditioned avoidance response. If DDT was given in the first trimester, or if 3 mg/kg of Parathion was given during the pregnancy, no effect on the conditioned avoidance response of the off-spring was seen.
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 12 (1968), S. 428-432 
    ISSN: 1432-2072
    Keywords: Ganglia, Basal ; Psychopharmacology ; Chlorpromazine ; Amphetamine ; Dopamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rats micro-injections in corpus striatum of quaternary chlorpromazine and related drugs give rise to highly characteristic neuroleptic effects: antagonism of amphetamine-induced stereotyped behaviour and development of catalepsy. There is no effect of injections in hippocampus or septum. Dopaminergic mechanisms in corpus striatum seem to play a central role in neuroleptic action.
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 13 (1968), S. 161-169 
    ISSN: 1432-2072
    Keywords: Sleep-wakefulness Cycle ; Amphetamine ; Psychopharmacology ; Growing Animals ; Electrencephalography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The effects of amphetamine on the sleep-wakefulness cycle were studied in 48 kittens during the growth period of 1–28 days of age. Recordings of EEG, EMG of the posterior neck muscles and respiratory rhythms were made as well as observations of gross behavior. 2. Percent time of wakefulness was increased with amphetamine (0.3 mg/kg). This effect became more marked with age, i.e., being more significant after 16 to 18 days of age (P〈0.005) than before (P〈0.05). These increases in the intensity of the effect during growth may be related to the postnatal development of the structures responsible for wakefulness. 3. Percent time of “activated” sleep was diminished significantly at all ages including the newborns (P〈0.005). This lack of the influence of age suggests that the structures responsible for “activated” sleep are well developed at birth. 4. The increase of percent time of slow wave sleep was observed. This increase is regarded as a “passive” manifestation of time left available after a severe diminution of “activated” sleep time and relatively slight increase of wakefulness time during amphetamine medication.
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  • 21
    Electronic Resource
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    Springer
    Psychopharmacology 13 (1968), S. 210-221 
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Animal Behaviour ; Nicotine ; Physostigmine ; Motor Activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats of 3 strains were observed at regular intervals and their activity was recorded using four categories of behaviour-rearing, moving, grooming and immobile. Strain differences in control activity were found. Nicotine and physostigmine reduced the activity of the more active rats and increased that of the less active animals. Rearing behaviour was particularly susceptible to depression by both drugs. The similarity of effect of the two drugs supports the hypothesis that one of the actions of nicotine in the brain is the release of acetylcholine.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 13 (1968), S. 287-298 
    ISSN: 1432-2072
    Keywords: Motion Pictures ; Motor Skills ; Eye Movements ; Psychopharmacology ; Psychological Tests
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Measures of skilled motor performances, both of a task-oriented (tests of eye-hand coordination) and incidental (control of facial and ocular muscles) nature were recorded for a sample of 20 healthy young adults before and after single administrations of perphenazine, opipramol, imipramine and placebo at doselevels commonly supposed to produce mood or behavioral effects. It was anticipated that such performances would be sensitive even to slight changes in the subjects' physiological and psychological state; the aim was to test the power of tests of subtle skills in providing indices of slight to moderate behavioral effects. The performance measures remained surprisingly little affected by all drugs, despite their sensitivity to drug-independent improvement in performance throughout the experimental day, and despite evidences of drug-related effects, especially for imipramine and opipramol, in simple objective physiological measures, and for imipramine alone in subjective measures taken concurrently. There may be a class of skilled sensory-motor acts, particularly those related to well-learned daily activities, which, rather than being vulnerable to adverse effect, remain efficient even in the presence of signs of disturbance of bodily function.
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  • 23
    ISSN: 1432-2072
    Keywords: Cannabis ; Lysergic Acid Diethylamide ; Mescaline ; Hallucinogens ; Psychopharmacology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using climbing rope and bar-pressing behavior methods, rats were rendered tolerant to Δ 9-THC, cannabis extract, mescaline and LSD-25. Cross-tolerance experiments showed that rats refractory to Δ 9-THC and cannabis extract were still sensitive to mescaline and LSD-25, and vice-versa. These results suggest that, in spite of the similarity of the clinical symptoms produced in man by the 3 drugs, Δ 9-THC may have its psychotomimetic effects produced by different mechanisms from those of LSD-25 and mescaline.
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  • 24
    Electronic Resource
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    Springer
    Clinical and experimental medicine 145 (1968), S. 270-277 
    ISSN: 1591-9528
    Keywords: Aldosterone ; Kidney ; Stop flow dog ; Aldosteron ; Niere ; Stop flow-Hund
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 146 (1968), S. 336-345 
    ISSN: 1591-9528
    Keywords: Aldosterone ; Kidney ; Man ; Aldosteron ; Niere ; Mensch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 26
    ISSN: 1591-9528
    Keywords: Plasma FFA composition ; Individual FFA extraction in heart ; Skeletal muscle ; Kidney ; Plasma-FFS-Zusammensetzung ; Extraktion der Einzel-FFS in Herz ; Skeletmuskel ; Niere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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