AJP - Regulatory, Integrative and Comparative Physiology, Vol 249, Issue 1 79-R84, Copyright © 1985 by American Physiological Society
Differential secretion and removal of multiple renin forms
D. N. Shier and R. L. Malvin
Hepatic clearance of renin in anesthetized dogs was measured during aortic
constriction and after nephrectomy. Aortic constriction caused a transient
increase in the hepatic extraction ratio for renin (ER) from 0.34 +/- 0.05
to 0.52 +/- 0.05, whereas nephrectomy caused the ER to decrease with time.
Isoelectric focusing of plasma samples over an average pH gradient of
4.0-6.2 yielded several peaks of renin activity. Peaks focusing above pH
5.0 were combined and arbitrarily classified as basic renin, whereas peaks
below pH 5.0 were classified as acidic renin. In each period the ER for
basic renin was significantly greater than that for acidic renin. The
proportion of basic renin was transiently increased at 10 min (59 +/- 4%)
compared with control (41 +/- 4%). This contributed to the increased ER
after constriction. The decreased ER after nephrectomy, however, was not
solely due to differential removal of these forms. We conclude that hepatic
clearance of renin is partly a function of the type of renin secreted by
the kidney, which in turn may change with the duration of the secretory
stimulus.
