胃泌素对垂体前叶催乳素和β-内啡肽分泌的影响  

Influence of Gastrin on Secretion of Prolactin and β-Endorphin in Anterior Pituitary

作　　者：许荣焜[1] 金镭[1] 黄曼影[1] 杨穗津[1] 时占祥[1] 黄醒亚[2] 

机构地区：[1]中国医学科学院基础医学研究所生理研究室 [2]自然科学基金委生命科学部

出　　处：《基础医学与临床》1991年第5期17-21,共5页Basic and Clinical Medicine

基　　金：国家自然科学基金(项目编号38970313)

摘　　要：给清醒自由活动的大鼠第三脑室内微量注射不同剂量的胃泌素(G-17).观察到1μg和5μg的G-17都抑制催乳素(PRL)的静息分泌,5μg G-17还可显著地抑制限制性应激时PRL的释放。1μg的G-17对β-内啡肽(β-EP)的静息分泌和应激释放都无明显-影响.但5μg的G-17既兴奋β-EP的静息分泌,也进一步兴奋限制性应激时β-EP的释放。离体实验的结果表明:0.05、0.5和1.0μg的G-17均增加体外培养的大鼠垂体前叶细胞PRL的分泌,且呈剂量相关效应;0.05和0.5μg的G-17不影响离体垂体前叶细胞β-EP的分泌,当G-17剂量达1.0μg时才显著增加离体垂体前叶细胞β-EP的分泌。上述结果提示,胃泌素抑制PRL的释放可能是通过下丘脑机制,因为胃泌素直接作用于垂体前叶细胞兴奋PRL的分泌:一定浓度的胃泌素无论中枢或外周的作用都兴奋β-内啡肽的分泌。Synthetic human gastrin ( G-17 ) was injected intraventricularly (1μg and 3μg/3 μl into the third cerebral ventricle)in conscious rats bearing an intrajugular cannu-la.Control injections of saline ( 3μl )into the 3rd ventricle did not modify plasma prolactin ( PRL ) and β-endorphin (β-EP ) levels.3rd ventricle injection 1μg or 5μg gastrin produced significant suppression of resting plasma PRL levels. The lowering was detected on first measurement at 10 min after injection and was maximal at 60 min.1μg gastrin had no effect on resting plasma β-EP levels,but increasing the dose to 5μg induced an elevation, which reached peak levels at 12 min after injection.1μg gastrin(3rd V.I) did not modify restraint stress-induced plasma PRL and β-EP elevation, but 5μg dose of gastrin produced significant suppression of plasma PRL levels and elevation of β-EP.In vitro incubation of dispersed anterior pituitary cells with 0.05, 0.5 and 1.0 μg gastrin increased PRL secretion, but only 1.0μg gastrin elevated significantly PRL and β-EP secretion.These results indicate that synthetic gastrin can inhibite resting and restraint stress-induced release of PRL and may implicate a hypothala-mic site of action for the peptide to inhibite release of PRL. However, gastrin stimulates res ting and restraint stress-induced release of β-EP in vivo and in vitro suggest that the peptide stimulates β-EP release at both levels of hypothalamus and anterior pituitary.

关 键 词：胃泌素 催乳素 Β-内啡肽 垂体 

分 类 号：R963[医药卫生—微生物与生化药学]