Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Physiology 30 (1968), S. 441-524 
    ISSN: 0066-4278
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Medicine , Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Physiology 49 (1987), S. 251-273 
    ISSN: 0066-4278
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Medicine , Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0090-6980
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Prostaglandins 24 (1982), S. 351-361 
    ISSN: 0090-6980
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Microchimica acta 59 (1971), S. 697-716 
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary The intracellular distribution of Na, K and Cl has been investigated by electron probe analysis in different regions and different tubular segments of rat kidneys. Kidneys of antidiuretic rats were frozen in liquid propane at −170° C. Sections of 6–7μm thickness were cut in a cryostate at −20° C, fixed on a thin nylon foil specimen holder and freeze dried at −40° C. Data were evaluated according to the “relativmethod” ofHall and coworkers. Furthermore data were obtained from thin NaCl, sanidin and several Agar-Agar solution standards for a quantitative evaluation according to the “absolute method” ofMarshall andHall. Using the relativ method the following results were obtained: 1. The intracellular concentrations of sodium and chlorine increase from the superficial layers of the renal cortex towards deeper layers of the cortex. 2. A more pronounced increase of the intracellular concentrations of sodium and chlorine in the outer zone of the renal medulla was found as compared to the cortex. 3. Distinct from sodium and chlorine no cortico-medullary gradient for potassium was observed. 4. Within the outer zone of the renal medulla a statistically significant gradient for Na and Cl has been found between the descending and the ascending limb of Henle's loop. These results are in agreement with the suggested hypothesis of renal countercurrent mechanisms.
    Notes: Zusammenfassung Mit einer Mikrosonde wurden Messungen der intrazellulären Verteilung der Elemente Na, K und Cl verschiedener Nephronabschnitte durchgeführt mit dem Ziel der intrazellulären Elektrolytgehaltsbestimmung. Hierbei wurden Nieren antidiuretischer Ratten in flüssigem Propan bei −170° C gefroren, in einem Kryostaten bei −20° C, 6 bis 7μm dicke Schnitte angefertigt — auf dünne Nylonfolienprobenhalter übertragen und diese anschließend bei −40° C gefriergetrocknet. Die Meßwerte wurden sowohl nach der Hallschen „Relativmethode“, als auch mittels NaCl, Sanidin und verschiedener Eichmischstandards der Absolutmethode vonMarshall undHall ausgewertet. Nach der Relativmethode zeigte sich: 1. Ein Anstieg der intrazellulären Konzentrationen von K, Na und Cl von der oberen zur tieferen Nierenrinde. 2. Ein sprunghafter Anstieg der intrazellulären Na- und Cl-Gehalte von der Rinde zum Nierenmark, jedoch kein Anstieg des K. 3. Ein signifikanter Unterschied der Na- und Cl-Gehalte zwischen den auf- und absteigenden Schleifenschenkeln im Nierenmark bzw. den Überleitungsstücken und Mittelstücken im Innenstreifen.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-0568
    Keywords: Rat kidney ; Microinjection ; Long loops of Henle ; Descending thin limbs ; Ascending thin limbs ; Luminal diameter pattern
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In Rattennieren, die während einer osmotischen Diurese fixiert waren, wurden einzelne lange Henlesche Schleifen mit einem Kunststoff injiziert. In histologischen Serienschnitten wurden die zusammengehörenden dünnen Schleifenschenkel in der Innenzone des Nierenmarkes aufgesucht und ihr Innendurchmesser bestimmt. Überall in der Innenzone sind die Innendurchmesser der dünnen absteigenden Schleifenschenkel erheblich kleiner als die der aufsteigenden Schleifenschenkel. Der Unterschied ist am Beginn der Innenzone am größten und nimmt zur Papilla hin ab. Schon kurz vor dem Schleifenscheitel weitet sich das Lumen einer Henleschen Schleife und vergrößert sich kontinuierlich im aufsteigenden Schenkel bis zur Grenze zur Außenzone hin.
    Notes: Summary Long loops of Henle in rat kidneys fixed during an osmotic diuresis were marked by microinjection with a silicone rubber. In histological serial sections corresponding descending and ascending thin limbs in the inner medullary zone were identified and their luminal diameters measured. At any level of the inner medulary zone, the luminal diameter of descending limbs is considerably smaller than that of corresponding ascending limbs. This diameter difference is most drastic at the border between inner and outer zones and diminishes towards the bend of the loops. Starting with a pre-bend enlargement the ascending thin limbs increase in diameter towards the outer medullary zone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 129 (1969), S. 128-134 
    ISSN: 1432-0568
    Keywords: Microdissection ; Tubular segment length ; Proximal convolution ; Loop of Henle ; Kidney weight
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An den Nieren von Ratten zweier unterschiedlicher Stämme wurde die Länge oberflächlich gelegener Nephrone mit der Mikrodissektionsmethode bestimmt. Dabei war eine direkte Korrelation zwischen dem Nierengewicht und den einzelnen Abschnitten des Nephrons (proximales Konvolut, Henlesche Schleife, distales Konvolut) nachweisbar. Die mittlere Länge des proximalen Konvoluts betrug für ein Nierengewicht von 1 g 5,91 mm und für die Henlesche Schleife einschließlich der pars recta des proximalen Tubulus 6,5 mm. Die Umbiegungsstelle von Schleifen oberflächlich gelegener Nephrone lag immer im äußeren Nierenmark. Diese Längenvariationen in Abhängigkeit vom Nierengewicht sind auch auf das Körpergewicht beziehbar, da sich eine annähernd lineare Beziehung zwischen Nierengewicht und Bruttokörpergewicht ergab.
    Notes: Summary Anatomical investigations have been carried out on rats of two different strains. The kidney weight was shown to be linearly dependent upon body weight. Microdissections of superficial nephrons revealed that there is a significant correlation between kidney weight and the length of the proximal convolution, loop of Henle and distal convolution. The mean length of the proximal convolution in a 1 g kidney was 5.91 mm, and of the loop of Henle (pars recta of the proximal tubule included) 6.50 mm. The bend of loops of Henle belonging to superficial nephrons was always situated in the outer medulla.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 138 (1972), S. 301-319 
    ISSN: 1432-0568
    Keywords: Rat kidney ; Microinjection ; Short-looped nephron ; Long-looped nephron Ranal architecture ; Renal medullary function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um die histotopographischen Beziehungen von kurzen und langen Henleschen Schleifen in der Rattenniere zu bestimmen, wurden einzelne Nephrone durch Injektion mit einem Kunststoff gekennzeichnet und ihr Verlauf in histologischen Serienschnitten verfolgt. Die kurzen Henleschen Schleifen der Rattenniere gehören zu den oberflächlichen und intermediären Nephronen; sie alle haben einen sehr ähnlichen Verlauf. In den Markstrahlen der Nierenrinde und im Außenstreifen des Nierenmarkes liegen die zusammengehörenden Schenkel einer Schleife nebeneinander und gleichzeitig in der Nähe des zugehörigen Sammelrohres. An der Grenze zum Innenstreifen biegen die absteigenden Schleifenschenkel zu einem Gefäßbündel hin, in dessen Peripherie sie absteigen — eng assoziiert mit aufsteigenden venösen Vasa recta. Am Ende des Innenstreifens biegen sie um; ihre aufsteigenden Schenkel verlaufen in der Nähe von Sammelrohren. Die langen Henleschen Schleifen gehören zu den juxtamedullären Nephronen. Im Gegensatz zu den geraden Anteilen des distalen Tubulus verlaufen die „geraden Anteile” des proximalen Tubulus der langen Schleifen im Außenstreifen gewunden. Im Innenstreifen verlaufen ihre absteigenden Schleifenschenkel abseits der Gefäßbündel zwischen aufsteigenden Schleifenschenkeln, während ihre aufsteigenden Schenkel häufig in der Nähe eines Gefäßbündels liegen. In der Innenzone haben weder die absteigenden noch die aufsteigenden Schleifenschenkel charakteristische histotopographische Beziehungen. Die strenge Ordnung der Strukturen im Innenstreifen der Rattenniere läßt vermuten, daß hier die Lagebeziehungen der Henleschen Schleifen für ihre Funktion von Bedeutung sind, während in der Innenzone die genaue Zuordnung der Schleifenschenkel zu anderen Strukturen für funktionell wenig bedutend erachtet wird.
    Notes: Summary To determine the histotopographical relations of short and long loops of Henle in the rat kidney single short and long-looped nephrons were marked by microinjection with a silicone rubber and subsequently traced in histological serial sections. Short loops of Henle, derived from both supericial and midcortical nephrons, follow a similar course and possess similar histotopographical relations. In the medullary rays of the renal cortex and in the outer stripe of the outer medullary zone both limbs of short loops of Henle are lying together, near to the corresponding collecting duct. At the transition of outer and inner stripes the descending limbs turn towards the bundles and descend in the bundle periphery juxtaposed to venous vasa recta. After looping back at the junction of outer and inner zones they change position and ascend distant from the bundles in the vicinity of collecting ducts. The straight proximal portions of long-looped nephrons directly penetrate the outer stripe transversing this zone in tortuous course. In the inner stripe, the thin descending limbs of long loops of Henle descend distant from the bundles among the ascending thick limbs. In the inner medullary zone, neither the descending nor the ascending thin limbs have an exactly defined constant histotopographical position. The long loops ascend straight through the outer medullary zone, usually near to a vascular bundle, and reach the convoluted portion without transversing the medullary rays. The regularity of the histological pattern in the outer medullary zone suggests that the arrangement of the loops may influence their function, whereas in the inner zone the histotopographical position of the loop limbs does not appear to be a functionally important parameter.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-2013
    Keywords: Tubulo-Glomerular Feedback ; Stop Flow Pressure ; Nephron Filtration Rate ; DOCA Treatment ; Renin Activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present experiments were performed to study the effect of chronic extracellular volume expansion on the magnitude of tubulo-glomerular feedback responses in the rat kidney. Extracellular volume expansion was achieved by giving isotonic saline as drinking water and by injecting DOCA in a dose of 2.5 mg/kg · day. When Ringer perfusion rate through the loop of Henle was elevated in control rats (receiving only saline as drinking water) stop flow pressure (SFP) fell by an average of 0.47±0.81 mm Hg (mean±S.D.) and 7.93±2.85 mm Hg at the flow rate steps of 0–15 nl/min and 15–40 nl/min respectively. SN-GFR was reduced by a mean of 1.3±0.97 nl/min (0–15 nl/min) and 10.3±2.45 nl/min (15–40 nl/min). In DOCA treated rats the mean reductions of SFP were 0.98±0.9 mm Hg and 2.1±1.4 mm Hg and of SN-GFR 0.06±1.8 nl/min and 1.94±2.3 nl/min. Thus, significantly smaller changes of both SFP and SN-GFR were found in DOCA treated animals when flow rate was elevated from 15–40 nl/min. Net loop NaCl absorption rates did not significantly differ between control andDOCA rats. Renin activity of 5 pooled microdissected glomeruli was 15.6±17.1 ng/hr·0.1 ml in control and 2.94±2.6 ng/hr·0.1 ml in DOCA treated rats (P〈0.01). It is possible therefore that the reduced feedback reactivity in DOCA treated rats is related to the diminished juxtaglomerular renin activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 362 (1976), S. 229-240 
    ISSN: 1432-2013
    Keywords: Rat kidney ; Microperfusion ; Loop of Henle ; Tubulo-glomerular feedback ; Chloride transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To define the luminal agent(s) responsible for the reduction of nephron filtration rate following increases of loop of Henle flow rate early proximal flow rate (EPFR) during loop perfusion with 17 different salt solutions were compared to the non-perfused fubules. During orthograde microperfusions a reduction of EPFR as indication of a feedback response was noted with a number of nonovalent Cl− and Br− salts (LiCl, KCl, NaCl, RbCl, CsCl, NH4Cl, choline Cl, NaBr, KBr), with Na+ salts except Na acetate (NaHCO3, NaNO3, NaF, NaI, NaSCN), and with CaCl2 and MgCl2. These latter 2 solutions where used in a concentration of 70 mM while all other solutions had a concentration of 140 mM. During retrograde perfusion from the distal to the proximal end of the loop of Henle EPFR fell significantly with Cl− and Br− salts with percentage changes of EPFR ranging from −8.0 to −44.3%. In contrast, Cl− free salts and Cl− salts of divalent cations were associated with percentage changes of EPFR ranging from +7.1 to −6.2%, significance being reached only during perfusion with NaSCN. When furosemide (5×10−4M) was added to NaBr or KBr a feedback response was not observed. During orthograde perfusion with NaNO3 distal Cl− concentrations were 44.2±5.08 mM (mean±S.E.) at a perfusion rate of 10nl/min and 59.1±3.93 mM at a rate of 40 nl/min. CaCl2 perfusion induced a marked elevation of distal Cl− concentrations to levels higher than 140 mM. Loop chloride handling was normal during RbCl perfusion. The magnitude of the feedback response during retrograde perfusion was not changed by lowering NaCl concentration from 140 to 60 mM, but fell when NaCl concentration was further reduced. In contrast to orthograde perfusions it was insensitive to changes in flow rate. Our results are compatible with the thesis that feedback responses depend critically upon the rate of Cl− transport probably across the macula densa cells. Br− ions can replace Cl− because they appear to share a common transport pathway which can be inhibited with furosemide. Unspecificity of feedback responses during orthograde microperfusions is due to presence of Cl− ions in the macula densa region even when solutions are initially Cl− free. Cl− salts of divalent cations do not elicit a feedback response because Cl− transport is severely curtailed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...