Influence of the renin-angiotensin system on the autoregulation of renal blood flow and glomerular filtration rate in conscious dogs.
Renal autoregulation of blood flow (RBF) and glomerular filtration rate (GFR) were examined in 10 conscious foxhounds under a normal sodium diet before and after a continuous intrarenal converting-enzyme inhibition (CEI) or during the application of the angiotensin II antagonist saralasin. In order to prevent alpha-adrenergic interference, phenoxybenzamine was infused into the renal artery. In contrast to studies performed in salt depleted dogs there was no impairment of RBF or GFR autoregulation after CEI or saralasin. Renal blood flow was autoregulated at a level of 3.81 +/- 0.18 ml min-1 g-1 in the control group, 3.98 +/- 0.16 ml min-1 g-1 after CEI and 3.97 +/- 0.41 ml min-1 g-1 after saralasin. The lowest point of autoregulation was very much the same between the individual groups (control: 65.0 +/- 1.4 mmHg; CEI: 66.5 +/- 4.6 mmHg; saralasin: 67.4 +/- 3.2 mm Hg). GFR acted in a similar manner (autoregulation level control: 0.50 +/- 0.03 ml min-1 g-1; CEI: 0.52 +/- 0.05 ml min-1 g-1; saralasin. 0.50 +/- 0.04 ml min-1 g-1). The lowest pressure of GFR autoregulation differed slightly more (control: 81.5 +/- 2.2 mmHg; CEI: 93.2 +/- 4.2 mmHg; saralasin: 85.9 +/- 2.1 mmHg). The results suggest that the renal autoregulation of GFR and RBF is independent of the renin-angiotensin system in conscious dogs during a normal sodium diet.
Persson
P
P
I. Physiologisches Institut, Universität Heidelberg, FRG.
Ehmke
H
H
Kirchheim
H
H
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage*; D000818:Animals; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D006706:Homeostasis / Q000187:drug effects*; D012079:Renal Circulation / Q000187:drug effects*; D012084:Renin-Angiotensin System / Q000187:drug effects*; D012504:Saralasin / Q000008:administration & dosage*
D000806:Angiotensin-Converting Enzyme Inhibitors; D012504:Saralasin