Comparison between the effects of FSH and LH on the steroidogenic pattern in isolated pre-ovulatory rat follicles.
The effects of purified FSH preparations from three different species (ovine, human, rat) on the steroidogenic pattern in isolated pre-ovulatory follicles of PMSG-treated immature rats were examined and compared to the effects of LH (ovine, human). Steroids were analyzed by RIA. During 6 h incubation, all three FSH preparations in a concentration range from 10-100 ng/ml caused a significant increase in progesterone (P), testosterone (T), and oestradiol (E2) accumulation. With LH a significant increase in steroid accumulation was seen in a concentration of 1 ng/ml. The time-course of stimulation by hFSH and hLH in a concentration of 10 ng/ml showed no difference in steroidogenic response between the two hormones, with a significant stimulation of steroids within 2 h. During prolonged incubation (6-8 h), accumulation of T was measured in the presence or absence of unlabelled 17 alpha-hydroxyprogesterone. Follicles exposed to LH did not increase their T formation, while follicles incubated in plain medium or in the presence of oFSH increased their T formation. In a concentration of 100 ng/ml hFSH showed a tendency to reduce maximal T production. These results suggest that FSH alone in physiological doses may stimulate T and E2 production in the preovulatory follicle.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000096:biosynthesis*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006801:Humans; D007986:Luteinizing Hormone / Q000494:pharmacology*; D006080:Ovarian Follicle / Q000378:metabolism*; D011374:Progesterone / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D012756:Sheep; D013739:Testosterone / Q000096:biosynthesis*
D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone