大鼠应激性溃疡幽门区降钙素基因相关肽变化对胃内胆汁反流的影响

目的:探讨大鼠应激性溃疡时幽门区局部降钙素基因相关肽(calcitonin gene-related peptide, CGRP)变化对胃内胆汁反流影响.方法:采用冷束缚应激方法复制应激性溃疡的模型,将60只大鼠分为3组,对照组10只,实验组30只,干预组20只.分别检测其胃内胆汁酸的浓度,胃黏膜的溃疡指数(用Guth评分)以及pH值,用放免试剂盒检测幽门区降钙素基因相关肽含量,用免疫组化SP法检测胃幽门区CGRP神经元阳性反应产物CGRP-ir的平均光密度变化.结果:应激后2h胃内胆汁酸和pH值均达到峰值,应激后4h胃内溃疡指数达到峰值,而幽门区降钙素基因相关肽也在应激后4 h降到波谷.幽门区局部给予CGRP拮抗剂能显著降低应激性溃疡大鼠在2,4,6h三个时段胃内胆汁反流;免疫组化显示应激大鼠胆汁反流增加时,胃幽门区CGRP免疫反应阳性物质活性降低.幽门区CGRP含量与溃疡指数存在一定负相关.结论:CGRP参与了幽门括约肌舒张功能的调控,而其拮抗剂能明显降低局部CGRP含量,并显著减少胆汁反流,降低溃疡指数.

Effects of Pyloric Local Calcitonin Gene-related Peptide on Bile Acid Reflux to Rat Stomach

Objective: To investigate the effects of pyloric local CGRP on bile reflux to rat stomach with stress ulcer.Method: Rats stress ulcer model was established by cold water soaking.Sixty adult SD rats were randomly divided into three groups: the normal control group,the stress group and the antagonist group.The gastric ulcer index,pH and bile acid of gastric juice were measured before and after stress.The pyloric local CGRP was measured by a radioimmunoassay detection kit.CGRP immuno-reactivity neurons in gastric sphincter were studied by immunocyclechemical SP method.Result: The bile acid and pH of gastric juice reached the maximum at 2 hours after stress.The ulcer index did it at 4 hours after stress.But the pyloric local CGRP decreased to the minimum at 4 hours after stress.However,the bile acid in the hCGRP8-37 group was less than that of the antagonist control group.And the activity of the pyloric local CGRP immunoreactivity decreased in the hCGRP8-37 group.The pyloric local CGRP has the negative correlation with intragastric ulcer index.Conclusion: CGRP can promote bile acid reflux in the stomach for affecting and regulating the relaxation function of the pyloric sphincter.