Relationship of follicle stimulating hormone (FSH)-sensitive adenylate cyclase activity to FSH binding in immature rat ovaries following administration of pregnant mare serum gonadotrophin.
The time and dose-response relationships of human follicle stimulating hormone (hFSH)-sensitive adenylate cyclase activity to hFSH binding was studied in the immature rat ovary following an sc injection of pregnant mare serum gonadotrophin (PMSG). When an optimal dose of PMSG (10 IU/rat) was administered, a marked increase in hFSH-sensitive activity was observed at day 2, followed by a sharp decline at day 3. This was accompanied by a parallel rise and fall in ovarian hFSH binding activity. When immature rats were given various doses (5-100 IU/rat) of PMSG for 2 days, hFSH-sensitive adenylate cyclase activity increased sharply and maximal stimulation was obtained at 10 IU/rat. A close correlation was also observed with respect to dose-response for hCG-sensitive adenylate cyclase and hCG binding activities. It is concluded that: 1) PMSG administration with an optimal dose to the immature rat induced ovarian FSH and LH-hCG receptors, and an adenylate cyclase system highly sensitive to hFSH and hCG, and 2) the acquisition and responsiveness of adenylate cyclase to gonadotrophins are closely related to the appearance and the numbers of gonadotrophin receptors.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D010053:Ovary / Q000254:growth & development / Q000378:metabolism*; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism; D011962:Receptors, FSH; D011974:Receptors, LH
D006064:Gonadotropins, Equine; D011956:Receptors, Cell Surface; D011962:Receptors, FSH; D011974:Receptors, LH; D005640:Follicle Stimulating Hormone; D000262:Adenylyl Cyclases