Existence of renin in the endothelium of human artery

OBJECTIVE: The existence and localization of renin in situ was examined in human arteries under non-pathological conditions. DESIGN: Biochemical and immunohistochemical procedures were adopted to examine the existence of renin in human gastroepiploic arteries using an antibody raised against human recombinant renin or a specific renin inhibitor. METHODS: (1) Renin activity (angiotensin I generating activity sensitive to antihuman recombinant renin antibody or a specific renin inhibitor) in the homogenate of human gastroepiploic arteries with and without endothelium was compared; (2) vascular renin was immunohistochemically stained using a modified avidin-biotin-peroxidase complex method. RESULTS: (1) Renin activity in human gastroepiploic arteries with endothelium was significantly higher than in those without endothelium; (2) immunoreactive staining selectively occurred in the endothelial cells of human gastroepiploic arteries. CONCLUSIONS: Renin is present in endothelial cells of human arteries under non-pathological conditions. Endothelial renin may play a role in the control of vascular tone through local production of angiotensin II.