5-CT or DOI augments TRH analog-induced gastric acid secretion at the dorsal vagal complex.
5-CT or DOI augments TRH analog-induced gastric acid secretion at the dorsal vagal complex.
复制标题
5-CT 或 DOI 增强 TRH 类似物诱导的背侧迷走神经复合体胃酸分泌。
DOI：
10.1152/ajpregu.1997.273.5.r1607
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
StephensJr,RL
中科院分区：
文献类型：
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作者：
Varanasi,S;Chi,J;StephensJr,RL
5-羟色胺（5-HT）在迷走背复合体（DVC）与促甲状腺素释放激素（TRH）相互作用，增强TRH诱导的胃酸分泌刺激。为了研究参与增强反应的5-HT受体家族，将原型5-HT受体选择性激动剂（146 pmol）与TRH类似物RX-77368 （RX; 12 pmol）以30-nl的体积共注射到大鼠DVC。DVC坐标相对于书写菖蒲为前0.2 mm，右0.2 mm，腹0.6 mm。与单独注射RX相比，RX与5-HT激动剂5-羧基氨基色胺（5-CT）或（±）-1-（4-碘-2,5-二甲氧基苯基）-2-氨基丙烷盐酸盐（DOI； 5- ht2激动剂）共注射胃酸排泄量增加183或103%。相反，2-甲基-5- ht （5- ht3激动剂）与RX联合注射对RX诱导的胃酸分泌增加没有影响。此外，与RX反应相比，联合注射SC-53116 （5- ht4激动剂）可使胃酸排泄量减少45%。使用相同剂量（5-CT/RX或DOI/RX）检查RX/5-HT激动剂在DVC更多吻侧区域的联合注射反应显示，只有5-CT有效地产生对TRH类似物的增强反应。结果表明，5-CT或doi敏感受体的激活增强了胃酸对注射到DVC中的TRH类似物的反应，而5- ht4受体的激活抑制了胃酸对TRH类似物的反应。因此，对几种5-羟色胺受体亚型的综合反应可能介导5-羟色胺在DVC诱导的TRH反应的变化。
Serotonin (5-HT) interacts with thyrotropin-releasing hormone (TRH) at the dorsal vagal complex (DVC) to augment TRH-induced stimulation of gastric acid secretion. To investigate the 5-HT receptor family involved in the augmentation response, prototypical 5-HT receptor-selective agonists (146 pmol) were coinjected with the TRH analog RX-77368 (RX; 12 pmol) into the rat DVC in a 30-nl volume. The DVC coordinates were 0.2 mm anterior, 0.2 mm right, 0.6 mm ventral with respect to the calamus scriptorius. Coinjection of RX with the 5-HT agonists 5-carboxyamidotryptamine (5-CT) or (±)-1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane hydrochloride (DOI; 5-HT2agonist) produced a 183 or 103% increase in gastric acid output compared with the RX injection alone. In contrast, coinjection of 2-methyl-5-HT (5-HT3agonist) with RX produced no effect on RX-induced increase in gastric acid secretion. Moreover, coinjection of SC-53116 (5-HT4agonist) decreased the gastric acid output by 45% compared with the RX response itself. Examination of the RX/5-HT agonist coinjection response in more rostral regions of the DVC using the same doses (5-CT/RX or DOI/RX) revealed that only 5-CT was effective in producing the augmented response to TRH analog. The results suggest that activation of 5-CT- or DOI-sensitive receptors augments, and of 5-HT4receptors inhibits, the gastric acid response to TRH analog injected into the DVC. Thus the integrated response to several serotonin receptor subtypes may mediate changes to the TRH response induced by 5-HT at the DVC.