AJP - Renal Physiology, Vol 258, Issue 3 717-F721, Copyright © 1990 by American Physiological Society
Glomerular effects of angiotensin II require intrarenal factors
T. B. Wiegmann, M. L. MacDougall and V. J. Savin
Urology and Kidney Research Center, University of Kansas, Kansas City 66103.
Glomerular ultrafiltration coefficient (Kf) of glomeruli isolated from
kidneys of normovolemic rats decreases following infusion of angiotensin II
(ANG II). Kf from isolated glomeruli after ANG II infusion in vivo and from
isolated perfused kidneys following infusion of ANG II in vitro was
measured to determine whether the decrease required the presence of
systemic factors. Filtration was induced in vitro and the maximum rate of
change in glomerular volume was used to calculate Kf. Glomerular capillary
hydraulic conductivity (Lp) was calculated from Lp = Kf/A where the
basement membrane area A was calculated as 3 X pi X D2. ANG II infusion in
vivo in rats diminished Lp from 3.19 +/- 0.19 to 1.96 +/- 0.13 and to 1.82
+/- 0.11 microliters.min-1.mmHg-1.cm-2, respectively. ANG II infusion into
isolated kidneys caused a similar decrease in Lp (3.55 +/- 0.11 to 2.37 +/-
0.07). ANG II infusion either in vivo or during isolated kidney perfusion
decreases Kf and Lp. ANG II effects do not require the presence of
extrarenal factors but depend on perfusion in situ since incubation of
isolated glomeruli with ANG II did not alter Kf.
