In-vivo and in-vitro steroidogenic activity of post-ovulatory ovarian follicles of the rabbit.
Pseudopregnancy was induced in rabbits by injection of 50 i.u. hCG into the lateral ear vein. Blood was collected on Days 0, 1, 2 and 6 after hCG from the lateral ear vein and, in some studies, from the ovarian vein as well. Ovaries were collected on Days 0, 1, 2 or 6 after hCG injection, and follicles (greater than 0.8 mm diam.) were obtained by microdissection. Concentrations of oestradiol-17 beta, testosterone and progesterone in blood and follicular homogenates were measured by RIA. Follicular steroidogenesis was increased significantly on Day 6 after ovulation, at the time when the corpus luteum transforms into an oestrogen-dependent tissue. The ability of developing post-ovulatory follicles to secrete steroids in vitro in response to a gonadotrophic stimulus also increased over this same time interval. Follicular oestradiol production on Days 1 and 2 of pseudopregnancy may synergize with the post-ovulatory secretion of FSH to promote further follicular growth in the pseudopregnant rabbit.
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004958:Estradiol / Q000096:biosynthesis* / Q000097:blood; D005260:Female; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000494:pharmacology; D006080:Ovarian Follicle / Q000378:metabolism*; D010053:Ovary / Q000098:blood supply; D010060:Ovulation; D011374:Progesterone / Q000096:biosynthesis*; D011555:Pseudopregnancy; D011817:Rabbits; D013739:Testosterone / Q000096:biosynthesis* / Q000097:blood; D014680:Veins
D006063:Chorionic Gonadotropin; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone