The role of alpha adrenoceptors in the vascular and estradiol secretory responses to stimulation of the superior ovarian nerve.

Electrical stimulation of the superior ovarian nerve in rats reduces both the plasma flow rate of ovarian venous blood (ovarian blood flow) and the ovarian estradiol secretion rate. Here, we examined the possible roles of alpha-adrenoceptors in these processes. The reduction of the plasma flow rate was blocked by an alpha 1- (prazosin), but not by an alpha 2- (yohimbine) adrenoceptor blocker. In contrast, the reduction of the estradiol secretion rate was blocked by yohimbine but not by prazosin. We conclude that ovarian vascular and estradiol secretory responses to superior ovarian nerve activation are mediated by alpha 1- and alpha 2-adrenoceptors, respectively.