Correlation between serotonin receptor 5HT3A and serotonin transporter expression in the gastric glands and symptoms of patients with functional dyspepsia

Abstract

Background : Functional dyspepsia (FD) is one of the most common syndrome of gastrointestinal disorders. The sensation of pain or burning of the epigastrium including postprandial fullness and early satiation are the symptoms of FD,
which were defined by ROME III criteria. Several factors have been suggested as the causes of FD including the functions of serotonin neurotransmission which has currently been featured in this study.

Objective : The purpose of this study was to determine the association between the expression of 5HT3A receptor and serotonin transporter on gastric gland cells in patients with FD.

Methods : Small pieces of the fundus, body and antrum of the stomach from twelve FD patients were collected by gastroscopy technique. The expression of 5HT3A receptor and serotonin transporter were analyzed by immunohistochemistry
technique.

Results : The expressions of 5HT3A receptor on the parietal cells and chief cells in the antrum were significantly different in FD patients with different symptoms. Patients with 2 symptoms (gastric distension and stomachache) showed
an increase of 5HT3A receptor expression. At the body region, serotonin transporters were significantly increased in enterochromaffin cells of FD patients with no stomachache when compared with FD patients with stomachache. Moreover, the expression of serotonin transporter on enterochromaffin cell in FD patients with distension was also found significantly higher than the FD patients with stomachache.

Conclusion : These results provided evidence to support that serotonin neurotransmission may play an important role in FD. The expression of 5HT3A receptor and serotonin transporter may be specifically related to specific symptoms in
each patient which may be useful for developing individual treatment of FD in the future.