胃肠肽在应激所致结肠动力紊乱中的作用

Potential role of gut peptides in stress-induced colonic motor disorder.

目的探讨应激后胃肠肽释放量有无变化及其与应激相关性结肠动力紊乱的可能联系。方法（１）于大鼠近、远端结肠预先装置应力传感器，记录清醒状态下大鼠在应激前、后的结肠动力；另于大鼠盲肠预先插管，采用注入５１Ｃｒ后测结肠内同位素扩布中心值（ＧＣ）的方法，比较受应激与否结肠传送速率的差异；（２）取受应激大鼠的血、结肠粘膜及肌层组织，测定其中Ｐ物质（ＳＰ）、血管活性肠肽（ＶＩＰ）、神经降压素（ＮＴ）、生长抑素（ＳＳＴ）、胃动素（ＭＯＴ）、亮－脑啡肽（Ｌｅｕ－ＥＮＫ）的含量，与未受应激大鼠比较；（３）对结肠装有传感器的大鼠静脉注射ＳＰ、ＶＩＰ、ＮＴ、ＳＳＴ等，以观察某些肽对结肠动力的在体效应；另取大鼠结肠环形肌条，观察上述肽对结肠肌收缩活性的离体效应。结果（１）应激后大鼠结肠动力显著增强，而结肠传送速率明显迟缓；（２）应激后大鼠血中ＶＩＰ、Ｌｅｕ－ＥＮＫ水平较应激前升高，结肠肌中Ｌｅｕ－ＥＮＫ含量降低，其他肽的释放量无变化；（３）体内及离体实验表明，ＳＰ和ＮＴ增强结肠收缩活动，ＶＩＰ和ＳＳＴ起抑制作用。结论大鼠应激期间ＶＩＰ和ＥＮＫ释放增多，ＥＮＫ的增加在于拮抗“应激激素”，又与应激所致结肠动力异常有关。ＶＩＰ释放增加一方?

Objective To explore the potential role of gut peptide in stress induced colonic motor disorder.Methods In 9 conscious Wistar rats pre equipped with strain gauge transducers on ascending and descending colon,colonic motility was recorded before,during and after stress.And colonic transit was evaluated by instilling 51 Cr into the cecum through chronically implanted cannula in each group of 16 rats with or without stress,and then calculating the geometric center(GC) of radioactivity.The contents of VIP,SP,NT,SST,MOT and Leu ENK in plasma,colonic mucosa and muscle layer were assessed in 16 stressed and 16 control rats.Exogenous peptides(VIP,SP,SST,NT)were intravenously administered in 9 rats to determine the colonic motor response.Also,the effects of peptides on colonic circular muscle strips were investigated.Resuits Motor activity was increased after stress,whereas colonic transit was delayed.In the stressed rats,plasma levels of VIP and Leu ENK were higher than those in controls.The content of Leu ENK in muscle tissue decreased.Both in vivo and in vitro studies showed that SP and NT excited,whereas VIP and SST inhibited colonic motor activity.Conclusion Release of certain peptides is altered by stress.Increased release of ENK and VIP may be involved in stress induced colonic motor disorder and in the regulation of“stress hormone”release.