In vitro steroidogenesis by primary to antral follicles in the hamster during the periovulatory period: effects of follicle-stimulating hormone, luteinizing hormone, and prolactin.
Hamster ovarian follicles at Stages 1 to 10 (Stages 1-4: follicles with 1-4 layers of granulosa cells (GC); Stages 5-7: 5-10 layers GC plus theca; Stages 8-10: antral follicles) were isolated on the morning of proestrus or estrus and incubated for 2 h in the absence or presence of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (Prl), progesterone (P4), 17 alpha-hydroxyprogesterone (17OHP), or androstenedione (A). Steroid accumulations in the media were measured by radioimmunoassay (RIA). On proestrus, without any hormonal stimulus, consistent accumulation of P4 through estradiol-17 beta (E2) occurred in low amounts only from Stage 6 and on; both FSH (5-25 ng) and LH (1-25 ng) significantly stimulated steroidogenesis by Stage 6-10 follicles, and the effects of FSH, except for Stage 10, were largely attributable to LH contamination. However, 25 ng FSH significantly stimulated A production by Stages 1-4, whereas 1-25 ng LH was ineffective. On estrus, follicles at all stages, especially 1-6, showed significant and dose-dependent increases in P4 production in response to FSH; both FSH and LH significantly stimulated P4 and 17OHP accumulation from Stage 5 onwards; however, there was no increase in A and E2 compared to controls. Even the smallest estrous follicles showed a shift to predominance of P4 accumulation. On proestrus, Prl had a negative influence on LH-induced accumulation of P4 and 17OHP by Stages 7-9 and 6-8, respectively, without affecting A or E2.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D006224:Cricetinae; D004971:Estrus / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006065:Gonadotropins, Pituitary / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000494:pharmacology; D008647:Mesocricetus; D006080:Ovarian Follicle / Q000187:drug effects* / Q000378:metabolism; D011359:Proestrus / Q000378:metabolism; D011388:Prolactin / Q000494:pharmacology; D013256:Steroids / Q000096:biosynthesis*
D006065:Gonadotropins, Pituitary; D013256:Steroids; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone