Endothelial Renin-Angiotensin Pathway: Evidence for Intracellular Synthesis and Secretion of Angiotensins

• Published in: Circulation research 1987-03, Vol.60 (3), p.422-428
• Main Authors: Kifor, Imre, Dzau, Victor J
• Format: Article
• Language: English
• Subjects: Angiotensin I - biosynthesis; Angiotensin II - biosynthesis; Angiotensin III - biosynthesis; Angiotensins - biosynthesis; Animals; Biological and medical sciences; Blood vessels and receptors; Cell Line; Endothelium - cytology; Endothelium - metabolism; Fundamental and applied biological sciences. Psychology; Intracellular Membranes - metabolism; Renin - metabolism; Renin-Angiotensin System; Vertebrates: cardiovascular system
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/01.res.60.3.422

Cultured bovine aortic endothelial cells (BAEC) contain renin and angiotensinogen. To examine whether angiotensins are synthesized intracellularly and secreted by these cells, we assayed cell extracts as well as serum-free media of intact confluent BAEC. Angiotensins were identified by their retention time on reverse phase high performance liquid chromatography and direct radioimmunoas-say. BAEC and their media contain angiotensin II and angiotensin III. The rate of angiotensin accumulation in the media was a nonlinear function of time; the highest rate occurred in the first 15 minutes. The amount of angiotensin II accumulated in 30 minutes exceeded 200% of the intracellular concentration and that of angiotensin III exceeded 500% of the initial intracellular content. Neither renin nor angiotensinogen could be detected in the media. The viability of these cells was supported by low lactic dehydrogenase activity in the media (