AJP - Renal Physiology, Vol 237, Issue 3 188-F195, Copyright © 1979 by American Physiological Society
Regional renin release by the cat kidney in vitro and in vivo
S. M. Jones, J. Torretti, J. S. Williams and S. F. Weinberger
Differences in the rate of renin release by superficial and deep areas of
the cat kidney cortex were studied in vitro and in vivo. Renin release in
vitro by outer cortical slices was significantly higher than by their inner
counterparts: 19.6 +/- 2.3 vs. 12.8 +/- 1.95 ng angiotensin I-h-1-mg fresh
tissue-1-h of incubation-1. In vivo blood was sampled from subcapsular
(outer cortical) and deep (inner cortical and medullary) renal venous
circulation from anesthetized cats. Renal venous minus arterial plasma
renin concentration was respectively, 4.3 +/- 1.12 and 1.9 +/- 1.04 ng
angiotensin I-ml-1-h-1 (P less than 0.01). By assuming that in these
experiments renal blood flow distribution was approximately equal to each
of the two areas of venous drainage, as reported in the isolated perfused
cat kidney, we infer from the regional differences in arteriovenous
concentration that the rate of renin release of the outer cortex is higher
than that of the innder cortex in the cat kidney in vivo. Tissue content of
renin was found to decrease toward the deep cortex. The results support the
concept that the rate of regional renin release correlates with tissue
renin content, at least under the conditions of the present experiments.
