AJP - Regulatory, Integrative and Comparative Physiology, Vol 248, Issue 1 23-R28, Copyright © 1985 by American Physiological Society
Hepatic clearance of renin after angiotensin blockade
J. A. Keiser, T. J. Opgenorth and J. C. Romero
Several investigators have reported that hepatic metabolism of renin can be
altered in pathophysiological states (e.g., high-output heart failure,
cirrhosis, acute metal toxicity). The hypothesis that circulating
angiotensin II may play a role in regulating renin metabolism by the liver
was tested in anesthetized dogs. Captopril (SQ 14255) or an angiotensin
II-competitive antagonist [( Sar1-Ile8]angiotensin II) was used for
blockade of the renin-angiotensin system in two separate groups of dogs.
The administration of captopril resulted in a significant fall in the
percent extraction of renin by the liver (P less than 0.01) and in the
clearance of renin (P less than 0.05). The group receiving the competitive
antagonist and time-control animals showed no significant change in renin
extraction or renin clearance by the liver. Our data do not support a role
for angiotensin II in the regulation of hepatic metabolism of renin, since
experiments utilizing the antagonist failed to produce a change. The
mechanism by which captopril alters renin metabolism appears to be
independent of its blockade of angiotensin II.
