title: Antigonadotropic activity of hop extract.
abstract: Biological activity of water soluble fractions F-1 and F-2, which were extracted from hop, was studied and its action mechanism was speculated using the immature female SD rats. Administration of the substance significantly inhibited the effects of pregnant mare serum gonadotropin (PMSG) on 22-day-old female rats. Thus, PMSG-induced increases in ovarian weight, estrogen secretion, number of ovulated egg, progesterone production, uterine thymidine kinase activity, and plasma LH level were suppressed significantly. Furthermore, addition of the substance to incubated ovarian cells of the second day after PMSG injection resulted in suppression of FSH-induced estradiol secretion in vitro, probably via cAMP-dependent mechanism. But addition of the substance to incubated pituitary cells from ovariectomized rats did not change in LH secretion.
authors.affiliation: Department of Endocrinology, Tokyo Medical and Dental University, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Okamoto
authors.forename: A
authors.initials: A
authors.lastname: Kumai
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000097:blood; D004958:Estradiol / Q000097:blood; D005260:Female; D006062:Gonadotropins / Q000037:antagonists & inhibitors*; D007986:Luteinizing Hormone / Q000097:blood; D010060:Ovulation / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D011374:Progesterone / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D013937:Thymidine Kinase / Q000378:metabolism; D014599:Uterus / Q000201:enzymology
chemical_list: D006062:Gonadotropins; D010936:Plant Extracts; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D000242:Cyclic AMP; D013937:Thymidine Kinase