Estradiol-17 beta and 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one production by isolated ovarian follicles of amago salmon (Oncorhynchus rhodurus) in response to mammalian pituitary and placental hormones and salmon gonadotropin.

The effects of mammalian pituitary and placental hormones and dibutyryl cyclic AMP (cAMP) on the production of estradiol-17 beta and 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17 alpha, 20 beta-diOHprog) by amago salmon (Oncorhynchus rhodurus) ovarian follicles in vitro were compared with partially purified chum salmon (Oncorhynchus keta) gonadotropin (SGA). Estradiol-17 beta production was examined using midvitellogenic ovarian follicles; SGA was the most effective hormone tested; at a dose of 1 microgram/ml it stimulated the production of approximately 4 ng/ml estradiol-17 beta. Ovine LH (o-LH) was about 0.5% as effective as SGA. Taking into account the relative purity of the preparations used, ovine FSH (o-FSH) was almost as effective as o-LH. Both HCG and bovine TSH (b-TSH) stimulated estradiol-17 beta production at high doses. Porcine ACTH (p-ACTH), ovine GH (o-GH), and ovine PRL (o-PRL) induced very modest increases in estradiol-17 beta; cAMP was highly effective. 17 alpha, 20 beta-DiOHprog production was examined using full-grown immature oocytes which were capable of maturing in vitro in response to 1 microgram/ml SGA. o-LH was about 0.5% as effective as SGA. o-FSH, b-TSH, and HCG appeared to be less effective in stimulating 17 alpha, 20 beta-diOHprog production, compared to estradiol-17 beta. o-GH and o-PRL induced marginal increases in production and p-ACTH had a very modest inverse dose-response effect.(ABSTRACT TRUNCATED AT 250 WORDS)