Abstract
Effects of gonadotropin and estrogen on the levels of prostaglandin (PG) in the rat ovary were investigated. PGF content in rat ovary, as measured by radioimmunoassay, was slightly higher than that by bioassay using rat stomach fundus, although there was no statistically significant difference. PGE and PGF levels in rat ovary during the estrous cycle were lowest on the day of diestrus, PGE was of the highest level on the day of estrus, and PGF on the day of proestrus. Both PGE and PGF were increased 24 hours after treatment with pregnant mare serum gonadotropin on the first day of diestrus. PGE was increased about 2.5 fold and PGF about 2.3 fold. PGF was significantly increased 24 hours after treament with estradiol on the first day of diestrus. These results suggest that gonadotropin may directly or indirectly regulate changes in ovarian PG content via actions of estrogen.
