Gradients of prorenin and active renin in ovarian venous and peripheral venous blood samples obtained simultaneously

Previous studies have demonstrated the presence of prorenin, active renin, and angiotensin II in human follicular fluid. The purpose of this study was to analyze prorenin, active renin, and ovarian steroids in ovarian venous blood and peripheral venous blood samples obtained simultaneously. We studied 10 premenopausal patients undergoing oophorectomy in various phases of the menstrual cycle. Prorenin levels in the ovarian venous effluent were more than twofold higher than levels in peripheral blood, 136.8 +/- 34.1 versus 35.6 +/- 8.3 ng angiotensin 1 per milliliter per hour (p less than 0.01). Active renin levels were also higher in ovarian venous blood than in peripheral venous blood, 12.9 +/- 2.5 versus 8.9 +/- 2.7 ng angiotensin 1 per milliliter per hour, but this difference did not achieve statistical significance (p = 0.07). Prorenin levels correlated with those of active renin in ovarian venous blood (r = 0.76, p less than 0.05), suggesting that prorenin is locally activated. In the peripheral circulation, estradiol levels correlated negatively with prorenin levels (r = -0.73, p less than 0.05), although prorenin levels did not correlate with steroid levels in ovarian venous blood. We conclude that prorenin is produced by the ovary throughout the menstrual cycle and may be locally activated.