Evidence for existence of inactive arterial renin-like enzyme in the rat

Inactive renin-like enzyme(s) in the arterial wall of the rat are converted to active renin-like enzyme in vitro by either "acid activation" (dialysis to pH 3.3 followed by dialysis to pH 7.4) or "protease-induced activation" (trypsin, alpha-chymotrypsin and glandular kallikrein). The molecular weights of the inactive renin-like enzyme(s) before trypsin activation were estimated to be about 68,000, 44,000, 36,000 and 30,000 by column chromatography. These findings may offer a new aspect for the role of the arterial renin-angiotensin system in the local control of vascular tone by interconversion of the inactive to the active renin-like enzymes in the arterial wall.