The Role Of The Serotonin Signaling System In Slow Transit Constipation

Objective: To investigate the role of serotonin signaling system in the pathophysiology of STC. Method: Envision immunohistochemical staining was used to investigate the expression and distribution of 5-HT,5-HT1A receptor,5-HT2B receptor,5-HT3 receptor,5-HT4 receptor,5-HT7 receptor,5-HT transporter(SERT),CGRP,AchE,NSE,S100 in 20 STC patients and 20 controls. We treated 32 STC patients with Tegaserod, a highly selective partial 5-HT4 receptor agonist, to evaluate its efficiency and safty.SPSS10.0 was used for statistics analysis. Result: In the colon of STC, the expression of 5-HT was significantly increased in mucosa. There was no difference in the expression of 5-HT1A receptor. The expression of 5-HT3 receptor was significantly decreased in ENS. The expression of 5-HT2B receptor was significantly decreased in the smooth muscle of human colon.So was the 5-HT4 receptor in mucosa and ENS. The expression of 5-HT7 receptor was significantly increased in the smooth muscle of human colon. In ENS, the expression of CGRP,AchE,NSE were significantly decreased,butS100 was increased. The expression of SERT was decreased in mucosa ,the same with the SERT in ENS. Tegaserod could efficiently relieve the symptoms of STC. Conclusion: Serotonin signaling system may responsible for the pathophysiology of STC. It can be a target to treat STC.