促甲状腺素释放激素对鲤鱼离体垂体生长激素分泌的调节作用。

The regulatory effects of thyrotropin-releasing hormone on growth hormone secretion from the pituitary of common carp in vitro.

机构信息

Department of Biology, Zhongshan University, Guangzhou, P.R. China, 510275.

出版信息

Fish Physiol Biochem. 1993 Jul;11(1-6):71-6. doi: 10.1007/BF00004552.

PMID:24202462

Abstract

The effects of thyrotropin-releasing hormone (TRH) on growth hormone (GH) and gonadotropin (GtH) release, and the influences of somatostatin (SRIF), the dopamine agonist apomorphine (APO) and extracellular calcium on basal and TRH-induced GH release were examined using an in vitro perifusion system for pituitary fragments of common carp (Cyprinus carpio). Five minute pulses of different dosages of TRH stimulated a rapid and dose-dependent increase in GH release from the perifused pituitary fragments with an ED50 of 9.7 ± 2.3 nM. TRH was ineffective on GtH release. SRIF significantly inhibited basal and TRH-induced GH release from the perifused pituitary fragments, and the effects of SRIF were dose-dependent. APO induced a dose-dependent increase in basal and TRH-stimulated GH release from the perifused pituitary fragments. Increasing the concentrations of extracellular calcium from 0 mM to 1.25 mM resulted in an increase in basal and TRH-induced GH release. The high dose of calcium (6.25 mM) caused a slight decrease in basal and TRH-induced GH release compared with those at a concentration of 1.25 mM.

摘要

使用鲤鱼脑垂体片段的体外灌流系统，研究了促甲状腺素释放激素（TRH）对生长激素（GH）和促性腺激素（GtH）释放的影响，以及生长抑素（SRIF）、多巴胺激动剂阿朴吗啡（APO）和细胞外钙对基础和 TRH 诱导的 GH 释放的影响。不同剂量的 TRH 脉冲刺激灌流脑垂体片段中的 GH 快速、剂量依赖性释放，其 ED50 为 9.7±2.3 nM。TRH 对 GtH 释放没有作用。SRIF 显著抑制灌流脑垂体片段中的基础和 TRH 诱导的 GH 释放，且作用呈剂量依赖性。APO 诱导灌流脑垂体片段中基础和 TRH 刺激的 GH 释放呈剂量依赖性增加。将细胞外钙浓度从 0 mM 增加到 1.25 mM 会导致基础和 TRH 诱导的 GH 释放增加。与 1.25 mM 浓度相比，高钙（6.25 mM）剂量会导致基础和 TRH 诱导的 GH 释放略有减少。