We have located links that may give you full text access.
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Obstructive nephropathy in the rat: possible roles for the renin-angiotensin system, prostaglandins, and thromboxanes in postobstructive renal function.
Journal of Clinical Investigation 1980 Februrary
Relief of unilateral ureteral obstruction (UUO) of 24 h duration in rats is followed by severe renal vasoconstriction in the postobstructive kidney (POK). The present study examined possible roles of renal prostaglandins (PG) and thromboxanes (TX), as well as the renin-angiotensin system, in this vasoconstriction. Administration of the cyclooxygenase inhibitor indomethacin, which blocks both PG and TX production, failed to improve POK hemodynamics in UUO rats. To explore the possible role of the TX compounds, which include the potent vasoconstrictor thromboxane A2 (TXA2), UUO rats were infused with imidazole, an agent that blocks synthesis of TX, but not of PG. Imidiazole led to two- to threefold increases in the clearance of both inulin and rho-aminohippuric acid by the POK. This effect of imidazole was abolished by indomethacin, suggesting that the amelioration of POK vasoconstriction by imidazole was a result of inhibition of vasoconstrictor TX synthesis (e.g. TXA2), with PG vasodilators (e.g. PGE2 or PG12) still active. Urea, infused in a solution whose osmolality and volume were identical to the imidazole infusion, failed to improve hemodynamics in the POK, making it unlikely that nonspecific effects of volume expansion or osmotic diuresis mediated the beneficial effect of imidazole. Further studies examined the possible role of the renin-angiotensin systems in the vasoconstriction of the POK. UUO rats infused with the angiotensin II antagonist, Saralasin, exhibited no significant improvement in POK function, a finding that might be at least partly attributable to agonist/vasoconstrictor properties of Saralasin. In other experiments, treatment of UUO rats with the angiotensin-converting enzyme blocker SQ 14225 (Captopril), in order to inhibit angiotensin II formation, led to at least twofold increases in the clearance of both inulin and rho-aminohippuric acid in the POK. It is unlikely that Captopril exerted this beneficial effect by potentiating the vasodilator kinins, because the effect was not diminished by administration of either carboxypeptidase B (which destroys the kinins) or Trasylol (which blocks kinin synthesis). Thus, these results suggest that both angiotensin II, as well as metabolites of the PG-TX system, may be important determinants of postobstructive renal hemodynamics in the rat.
Full text links
Related Resources
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app