Taché Y, Yoneda M, Kato K, Király A, Sütö G, Kaneko H
CURE/VA-UCLA Gastroenteric Biology Center, VA Wadsworth Medical Center, Los Angeles, CA 90073.
J Gastroenterol Hepatol. 1994;9 Suppl 1:S29-35. doi: 10.1111/j.1440-1746.1994.tb01298.x.
The vagus is involved in mediating gastric cytoprotection and adaptive cytoprotection. However, the central and peripheral mechanisms through which the vagus expresses its action are still poorly known. Medullary thyrotropin-releasing hormone (TRH) plays an important role in the vagal regulation of gastric function. The stable TRH analogue, RX 77368, micro-injected into the cisterna magna or the dorsal motor nucleus (DMN) of the vagus at a dose that did not influence gastric acid secretion prevented gastric injury induced by intragastric administration of 60% ethanol in conscious or urethane-anaesthetized rats. The cytoprotective action of TRH is mediated through vagal cholinergic release of prostaglandin E2 (PGE2). Prostaglandin E2 action is unrelated to changes in gastric mucosal blood flow (GMBF). In addition, other peripheral mechanisms involve calcitonin gene-related peptide (CGRP) contained in capsaicin sensitive afferent fibres and nitric oxide, both of which mediate the associated increase in GMBF induced by intracisternal injection of RX 77368. These data indicate that medullary TRH induces vagally mediated gastric protection against ethanol lesions. Its action is expressed through the muscarinic dependent release of PGE2 and nitric oxide, and efferent function of capsaicin-sensitive afferent fibres releasing CGRP.
迷走神经参与介导胃细胞保护和适应性细胞保护。然而，迷走神经发挥其作用的中枢和外周机制仍知之甚少。延髓促甲状腺激素释放激素（TRH）在迷走神经对胃功能的调节中起重要作用。将稳定的TRH类似物RX 77368以不影响胃酸分泌的剂量微量注射到清醒或氨基甲酸乙酯麻醉大鼠的脑池或迷走神经背运动核（DMN）中，可预防胃内给予60%乙醇引起的胃损伤。TRH的细胞保护作用是通过迷走神经胆碱能释放前列腺素E2（PGE2）介导的。前列腺素E2的作用与胃黏膜血流量（GMBF）的变化无关。此外，其他外周机制涉及辣椒素敏感传入纤维中含有的降钙素基因相关肽（CGRP）和一氧化氮，二者均介导脑池内注射RX 77368引起的GMBF相关增加。这些数据表明，延髓TRH诱导迷走神经介导的胃对乙醇损伤的保护作用。其作用通过毒蕈碱依赖性释放PGE2和一氧化氮以及释放CGRP的辣椒素敏感传入纤维的传出功能来表达。
