下丘脑外侧区注射TRH对大鼠胃酸分泌的影响

本文采用连续收集胃腔灌流法,观察下丘脑外侧区(LHA)注射促甲状腺激素释放激素(TRH)对大鼠胃酸分泌的影响,并分析TRH在LHA促进胃酸分泌的作用机制。结果表明:(1)LHA注射TRH(1μg)明显地刺激胃酸分泌;(2)预先向LHA注射酚妥拉明(10μg)、美多心安(5μg)及胃泌素抗体1μl(1:640)并不影响TRH的泌酸作用,如预先向LHA注射阿托品(5μg)则可消除TRH的泌酸效应;(3)垂体摘除及肾上腺切除均不影响TRH的泌酸作用;(4)隔下迷走神经切断后,LHA注入TRH的泌酸效应仍然出现,但持续时间显著缩短;腹腔交感神经节摘除后,TRH仍能促进胃酸分泌,但分泌量少而平稳。以上结果提示:LHA是TRH中枢泌酸效应的有关结构之一,其中枢机制是通过胆碱能M受体中介的,腹腔交感神经节和膈下迷走神经是TRH泌酸效应的传出途径。前者引起的泌酸反应出现较早且引起泌酸高峰,但持续时间短;后者则引起低平的持续分泌。

EFFECT OF LATERAL HYPOTHALAMUS INJECTION OF TRH ON GASTRIC ACID SECRETION IN RATS

In the present study the results were as follows: (1) Thyrotropin-releasinghormone (TRH) injected into the lateral hypothalamic area (LHA) increasedgastric acid output significantly; (2) The increase was not affected by centraladministration of phentolamine or metoprolol and gastrin antibody, but completelyabolished by atropine; (3) Hypophysectomy or adrenalectomy did not affect thegastric acid response to TRH nor vagotomy; (4) The time course of acid secretioninduced by TRH after celiac ganglionectomy did not show a peak response. The aforementioned results indicate that cholinergic M-receptor in LHA isinvolved in the central mechanism of acid secretion induced by TRH and thesympathetic nerve and vagus are the possible efferent pathways.