Expression Of Serotonin,Serotonin Receptors And Serotonin Transporter In The Colon Of Patients With 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-HT3 receptor, 5-HT4 receptor, 5-HT transporter(SERT), CGRP, AchE, NSE, S100 in 20 STC patients and 20 controls. ISH technic was used to investigate the expression of SERTmRNA in two groups. IMS computer analysis system was used for semi-quantitative analysis. We used PCR technique to investigate the polymorphism of 5-HTTLPR in 54 STC patients and 100 controls. We treated 32 STC patients with Tegaserod, a highly selective partial 5-HT4 receptor agonis, 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.So was the 5-HT4 receptor in mucosa and ENS. In ENS, the expression of CGRP, AchE, NSE were significantly decreased, but S100 was increased. The expression of SERT was decreased in mucosa , the same with the SERT and SERTmRNA in ENS. The frequency of S/S genotype and allele S of 5-HTTLPR were significantly higher in STC patients. 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.