Hubbard G M, Licht P
Gen Comp Endocrinol. 1985 Nov;60(2):154-61. doi: 10.1016/0016-6480(85)90309-0.
Ovaries from the leopard frog, Rana pipiens, and bullfrog, R. catesbeiana, were used to study potential direct extrapituitary effects of gonadotropin-releasing hormone (GnRH). GnRH alone did not alter steroid secretion from ovaries in either species. Ovarian fragments containing mature follicles from R. pipiens were incubated in several submaximal doses of homologous pituitary homogenate or purified bullfrog luteinizing hormone (LH) together with 1000 ng/ml GnRH. The addition of GnRH failed to alter testosterone (T) or progesterone secretion or germinal vesicle breakdown over a wide dose range of gonadotropin. The effects of supramaximal doses of pituitary homogenate on R. pipiens and the effects of homologous LH on T secretion by fragments of R. catesbeiana ovaries were also unaffected by the presence of GnRH. The lack of a GnRH effect on the dynamics of T secretion in the bullfrog was further confirmed in a superfusion system with homologous pituitary homogenate. This study fails to demonstrate an action of GnRH at the level of the ovary in two ranid species.
用豹蛙（北美林蛙）和牛蛙的卵巢来研究促性腺激素释放激素（GnRH）潜在的垂体外直接作用。单独使用GnRH不会改变这两种蛙卵巢的类固醇分泌。将含有北美林蛙成熟卵泡的卵巢片段与1000 ng/ml GnRH一起，用几种亚最大剂量的同源垂体匀浆或纯化的牛蛙促黄体生成素（LH）进行孵育。在促性腺激素的广泛剂量范围内，添加GnRH未能改变睾酮（T）或孕酮的分泌或生发泡破裂。北美林蛙垂体匀浆的超最大剂量的作用以及同源LH对牛蛙卵巢片段T分泌的作用也不受GnRH存在的影响。在使用同源垂体匀浆的灌注系统中，进一步证实了GnRH对牛蛙T分泌动态缺乏影响。本研究未能证明GnRH在两种蛙科物种的卵巢水平上有作用。
