抄録
Histological studies in rats have shown that the ovary receives autonomic nerves via the superior ovarian nerves (SON) and the ovarian plexus nerves (OPN). It is well known that hypothalamus-pituitary hormones regulate ovarian estradiol secretion. However, it has not yet been clarified whether the autonomic nerves innervating the ovary regulate ovarian estradiol secretion. In the present study, we examined the effects of electrical stimulation of SON and OPN on the ovarian estradiol secretion in rats. Rats were anesthetized on the day of estrous, and ovarian venous blood samples were collected through a catheter inserted into the ovarian vein. Estradiol concentration of ovarian venous plasma was measured using EIA. Electrical stimulation of SON at a supra-maximal intensity for C-fibers produced decreases in plasma flow rate (by about 26 ± 4%), estradiol concentration of ovarian venous plasma (by about 19 ± 8%), and estradiol secretion rate (by about 50 ± 6%). In contrast, electrical stimulation of OPN at supra-maximal intensity for C-fibers produced decrease in plasma flow rate (by about 35 ± 3%) but no changes in estradiol concentration of ovarian venous plasma and estradiol secretion rate. From these results, it is concluded that ovarian estradiol secretion is directly regulated by C-fibers in the SON in rat on the day of estrous. [J Physiol Sci. 2008;58 Suppl:S158]
