Glomerular effects of angiotensin II require intrarenal factors.
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.
Wiegmann
T B
TB
Urology and Kidney Research Center, University of Kansas, Kansas City 66103.
MacDougall
M L
ML
Savin
V J
VJ
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004231:Diuresis; D005919:Glomerular Filtration Rate; D066298:In Vitro Techniques; D007668:Kidney / Q000502:physiology*; D007678:Kidney Glomerulus / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009318:Natriuresis; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains
D000804:Angiotensin II