Release of norepinephrine from human ovary - Coupling to steroidogenic response

We investigated the possibility that norepinephrine from the human ovary is released after nerve stimulation and that this neurotransmitter is coupled to a steroidogenic response. Biologically significant levels of both norepinephrine and dopamine were found in human ovarian biopsies. [H-3]norepinephrine incorporated in vitro was readily released by electrical stimulation in a Ca2+-dependent process. Ovarian membrane preparations exhibited specific binding sites for the beta -adrenergic antagonist [H-3]dihydroalprenolol. Displacement of [H-3]dihydroalprenolol with zinterol (a specific beta (2)-agonist) indicated that 72 % of these sites were type beta (2)-receptors. beta -receptors were also present on granulosa cells. Stimulation of granulosa cells with luteinizing hormone or the beta -agonist isoproterenol increased the release of progesterone after 4 d in culture. These results suggest that the sympathetic nerves present in human ovary are coupled to beta -adrenergic receptors present in endocrine cells and, as in nonprimate mammals, appear to participate in the regulation of ovarian function.