Analysis of cortical urea sequestration in rat renal tissue slices
Purchase on Springer.com
$39.95 / €34.95 / £29.95*
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.
In antidiuretic rats plasma urea concentration (P u )was elevated up to 35 mM by intravenous urea loading. In renal cortical tissue (T) water content and unlabeled (u) and 14-C-urea (u *) were determined.
Water content of total renal cortex and of superficial and juxtamedullary layers were not significantly different and were not changed by the elevation ofP u .
In the control group (P u <10 mM), bothT/P u (3.06±0.71;n=29) and plasma specific activity were significantly higher than values forT/P u * (2.20±0.57;n=12) and tissue specific activity, respectively.T/P u andT/P u * were decreased significantly to the same level (1.68±0.35;n=20 and 1.51±0.21;n=7, respectively) atP u >20 mM and plasma and tissue specific activity became equal.
Deproteination of tissue homogenates did not depress 14-C-activity.
JuxtamedullaryT/P u was significantly higher than superficialT/P u .The difference was independent ofP u .
The data suggest, that renal cortical tissue urea concentration is determined (i) by distal tubular fluid urea concentration, which is inversely correlated withP u and (ii) by a constant amount of urea in an extraluminal compartment not readily exchanging.
The mechanism by which urea concentration in this extraluminal compartment is maintained independent ofP u might be urea neogenesis or urea binding to cellular structures or proteins.
- Armsen, T., Schad, H., Reinhardt, H. W.: Die Konzentrierung des Harnstoffs in der Niere. II. Mikropunktionsuntersuchungen an der Ratte. Pflügers Arch.313, 222 (1969)
- Beale, R. N., Croft, D.: A sensitive method for the colorimetric determination of urea. J. clin. Path.14, 418 (1961)
- Carlisky, N. J., Brodsky, W. A., Huang, K. C.: Biosynthesis of urea by the kidney in relation to the mechanism of urea excretion. Fed. Proc.21, 427 (1962)
- O'Dell, R. M., Schmidt-Nielsen, B.: Retention of urea by frog and mammalian kidney slices in vitro. J. cell. comp. Physiol.57, 211 (1961)
- Kleinman, L. J., Radford, E. P.: Urea synthesis by rat kidney. Physiologist7, 179 (1964)
- Kriz, W.: Der architektonische und funktionelle Aufbau der Rattenniere. Z. Zellforsch.82, 495 (1967)
- Rabinowitz, L.: In: Urea and the kidney, p. 340. Editor: B. Schmidt-Nielsen. Excerpta Medica ICS 195 (1970)
- Reinhardt, H. W., Schad, H., Armsen, T.: Zur Frage der Harnstoffkonzentrationen in den Kompartimenten der Nierenrinde (Ratte). Tissue slice-study of urea concentration in structures of the renal cortex (rat). Pflügers Arch.307, R74 (1969)
- Roch-Ramel, F., Chométy, F., Peters, G.: Urea concentrations in tubular fluid and in renal tissue of nondiuretic rats. Amer. J. Physiol.215, 429 (1968)
- Roch-Ramel, F., Diézi, J., Chométy, F., Michoud, P., Peters, G.: Disposal of large urea overloads by the rat kidney: a micropuncture study. Amer. J. Physiol.218, 1524 (1970)
- Roch-Ramel, F., Diézi, J., Chométy, F., Michoud, P., Peters, G.: Urea concentrations in tubular fluid and in renal tissue of rats overloaded with urea or with saline solutions. In: Urea and the kidney, p. 333. Editor: B. Schmidt-Nielsen. Excerpta Medica ICS 195 (1970)
- Roch-Ramel, F., Peters, G.: Intrarenal urea and electrolyte concentrations as influenced by water diuresis and by hydrochlorothiazide. Europ. J. Pharmacol.1, 124 (1967)
- Saikia, T. C.: Composition of the renal cortex and medulla of rats during water diuresis and antidiuresis. Quart. J. exp. Physiol.50, 146 (1965)
- Schmidt-Nielsen, B., O'Dell, R.: Structure and concentrating mechanism in the mammalian kidney. Amer. J. Physiol.200, 1119 (1961)
- Truniger, B., Schmidt-Nielsen, B.: Intrarenal distribution of urea and related compounds: effects of nitrogen intake. Amer. J. Physiol.207, 971 (1964)
- Truniger, B., Schmidt-Nielsen, B.: Intrarenal distribution and transtubular movement of urea and related compounds. In: Urea and the kidney, p. 314. Editor: B. Schmidt-Nielsen. Excerpta Medica ICS 195 (1970)
- Ullrich, K. J., Rumrich, G., Baldamus, C. A.: Mode of urea transport across the mammalian nephron. In: Urea and the kidney, p. 175. Editor: B. Schmidt-Nielsen. Excerpta Medica ICS 195 (1970)
- Valtin, H.: Sequestration of urea and non-urea solutes in renal tissues of rats with hereditary hypothalamic diabetes insipidus: effect of vasopressin and dehydration on the counter current mechanism. J. clin. Invest.45, 337 (1966)
- Analysis of cortical urea sequestration in rat renal tissue slices
Volume 346, Issue 1 , pp 31-38
- Cover Date
- Print ISSN
- Online ISSN
- Additional Links
- Urea Infusion
- Tissue Analysis
- Urea Sequestration
- Urea Binding
- Urea Neogenesis
- Industry Sectors
- Author Affiliations
- 1. Physiologisches Institut der Universität, München, Germany
- 2. Städt. Krankenhaus Westend Abt. f. exp. Anaesthesie, Freie Universität Berlin, Spandauer Damm 130, D-1000, Berlin 19
- 3. I. Medizinische Univ.-Klinik, Ziemssenstraße 1, D-8000, München 2, Federal Republic of Germany