促黄体生成素释放激素（LH-RH）和去甘氨酸10[D-丙氨酸6]促黄体生成素释放激素乙酰胺对成年雌性银大麻哈鱼（Oncorhynchus kisutch）血浆性类固醇水平的影响。

Effects of LH-RH and Des-Gly10[D-Ala6]LH-RH-ethylamide on plasma sex steroid profiles in adult female coho salmon (Oncorhynchus kisutch).

作者信息

Van der Kraak G, Dye H M, Donaldson E M

出版信息

Gen Comp Endocrinol. 1984 Jul;55(1):36-45. doi: 10.1016/0016-6480(84)90126-6.

Abstract

17 beta-Estradiol, testosterone, and 17 alpha, 20 beta dihydroxy-4-pregnen-3-one (17 alpha 20 beta P) levels were measured in plasma samples obtained from coho salmon (Oncorhynchus kisutch) during the preovulatory period and following the injection of mammalian gonadotropin releasing hormones. Spontaneous reproductive activity was characterized by a rapid decline in plasma 17 beta-estradiol 10 days prior to ovulation and a large increase in plasma 17 alpha 20 beta P 6 days before ovulation. Testosterone levels remained high (greater than 125 ng/ml) throughout the preovulatory period, with a small peak evident 6 days prior to ovulation. Oocyte development was not accelerated in fish injected with mammalian LH-RH, whereas des-Gly10[D-Ala6]LH-RH-ethylamide (LH-RHA DAla6) promoted germinal vesicle breakdown (GVBD) in 10 out of 14 fish within 96 hr. Only LH-RHA DAla6-injected fish which completed GVBD displayed the characteristic steroid changes observed during spontaneous reproductive activity. In LH-RH-injected fish, there was a transient increase in plasma 17 alpha 20 beta P levels which persisted for less than 24 hr. LH-RHA DAla6-injected fish which failed to complete GVBD maintained high 17 alpha 20 beta P levels, but the peak concentrations were lower than those in fish which completed GVBD. These fish also maintained high plasma 17 beta-estradiol levels when compared to fish which completed GVBD. The appearance of high plasma 17 alpha 20 beta P levels during spontaneous and LH-RHA DAla6-induced reproductive activity was coincident with the time of GVBD. This finding was consistent with the view that 17 alpha 20 beta P functions as the maturation-inducing steroid in salmonids. The induction of GVBD using gonadotropin-releasing hormones was related to the elevation of plasma gonadotropin levels for greater than 24 hr [G. Van Der Kraak, H. R. Lin, E. M. Donaldson, H. M. Dye, and G. A. Hunter (1983) Gen. Comp. Endocrinol. 49, 470-476] and a decrease in 17 beta-estradiol production.

摘要

在排卵前期以及注射哺乳动物促性腺激素释放激素之后，从银大麻哈鱼（Oncorhynchus kisutch）采集血浆样本，测定其中17β-雌二醇、睾酮以及17α,20β-二羟基-4-孕烯-3-酮（17α20βP）的水平。自发繁殖活动的特征是排卵前10天血浆17β-雌二醇迅速下降，排卵前6天血浆17α20βP大幅增加。在整个排卵前期，睾酮水平保持较高（大于125 ng/ml），在排卵前6天有一个小峰值。注射哺乳动物促性腺激素释放激素（LH-RH）的鱼，其卵母细胞发育并未加速，而在14条鱼中有10条在注射去甘氨酸10[D-丙氨酸6]促黄体素释放激素乙酰胺（LH-RHA DAla6）后96小时内发生了生发泡破裂（GVBD）。只有完成GVBD的注射LH-RHA DAla6的鱼才表现出自发繁殖活动期间观察到的典型类固醇变化。在注射LH-RH的鱼中，血浆17α20βP水平有短暂升高，持续时间不到24小时。未完成GVBD的注射LH-RHA DAla6的鱼维持较高的17α20βP水平，但峰值浓度低于完成GVBD的鱼。与完成GVBD的鱼相比，这些鱼的血浆17β-雌二醇水平也维持在较高水平。在自发和LH-RHA DAla6诱导的繁殖活动期间，血浆17α20βP高水平的出现与GVBD时间一致。这一发现与17α20βP作为鲑科鱼类成熟诱导类固醇的观点一致。使用促性腺激素释放激素诱导GVBD与血浆促性腺激素水平升高超过24小时[G. Van Der Kraak, H. R. Lin, E. M. Donaldson, H. M. Dye, and G. A. Hunter (1983) Gen. Comp. Endocrinol. 49, 470 - 476]以及17β-雌二醇产生减少有关。