The aim of this study was to identify immunologically and biologically a renin-like enzyme (RLE) in rat corpora lutea (CL). The biological activity of partially purified extracts of CL was tested in vivo by injection into anesthetized pentolinium-treated rats, obtaining a pressor response similar to renal renin. The enzyme activity in vitro was inhibited to about 50percent-flag-change by pretreatment with a specific antibody against renal renin. When the extracts were incubated with angiotensinogen, the product was inhibited mainly by angiotensin I antibody. The fact that there was no change in RLE content in 24 or 48 h nephrectomized rats, suggested the idea of a local production rather than an active blood renin sequestration.
