Ovarian renin production in vitro and in vivo: characterization and clinical correlation

The purpose of this study was to examine the in vitro production of prorenin and active renin by human theca cells and to examine the clinical significance of this production by correlating prorenin and active renin levels with oocyte maturity in follicular fluid samples. Human theca cell cultures were established and were found to produce both prorenin as well as active renin. Androstenedione levels (126 +/- 28 pg/500,000 cells/24-hr incubation) correlated with prorenin levels (8.5 +/- 1.1 ng angiotensin I per milliliter per hour (AI/ml/hr) in culture supernatant (r = 0.61, P less than 0.05). Active renin levels in follicular fluid were higher in stimulated versus spontaneous cycles (359 +/- 67 versus 126 +/- 37 ng AI/ml/hr, P less than 0.05). Renin substrate levels were similar in follicular fluid and in the peripheral serum (1,610 +/- 216 versus 2,160 +/- 490 ng/ml) in spontaneous cycles. Follicular fluid prorenin and active renin did not correlate with oocyte maturity or with steroid levels. The authors conclude that ovarian theca cells produce renin in vitro. However, renin production does not correlate with oocyte maturity or follicular fluid steroids in vivo.