Sources and regulation of prorenin and renin production within the uterus during pregnancy: Use of a direct immunoradiometric assay

Objective: To determine which cells derived from intrauterine tissues produce prorenin and renin and the potential mechanisms of regulation. Methods: Amnion, chorion, decidual and myometrial cells were derived from term pregnancies and grown to confluence. Incubations were conducted for 16 h in the presence and absence of dibutyryl cyclic AMP (dbcAMP, 1 mmol/l) or ionomycin (0.5 μmol/l). Prorenin and renin were measured directly in the culture media using a direct immunoradiometric assay. Results: Chorion (n = 6) and decidual (n = 6), but not amnion (n = 3) or myometrial (n = 4) cells produced measurable quantities of prorenin and renin with prorenin (> 95%) being the major species. Ionomycin and dbcAMP, respectively, inhibited and stimulated combined prorenin and renin output from chorion (n = 4) and decidual (n = 4) cells. Conclusions: Chorion and decidua are major intrauterine sources of prorenin and renin. The functions of prorenin and renin within the uterus remain uncertain but their ability to stimulate prostaglandin production suggests a potential role in the mechanisms of parturition.