Active renin and renin glycoform dynamics in the carotid artery

Abstract

Active renin and five major active renin glycoforms were measured in plasma and the carotid wall of anesthetized rabbits before and after 1.5- and 24-h bilateral nephrectomy (BNX). Before BNX, there was no difference in renin glycoform proportions between plasma and the carotid wall. Plasma renin concentration (PRC) fell by 67% after 1.5-h BNX due to preferential clearance of renin glycoforms I+II, but no significant change in renin concentration was seen in the carotid artery (or aorta). Twenty-four hours after BNX, PRC and carotid wall renin concentrations were reduced by 99.7 and 97.7%, respectively, while the proportion of renin glycoforms I+II in the carotid wall was significantly elevated. These data are consistent with the view that vascular renin is derived from plasma renin of renal origin. After BNX, renin disappearance from the carotid (and aortic wall) is slower than renin decay from plasma, and the less negatively charged active renin glycoforms I+II exit the carotid wall much more slowly than the more negatively charged glycoforms. After 24-h BNX, renin glycoforms I+II were still effluxing from the vascular wall and represented the only glycoforms present in the carotid wall.