Correlation between the expression of serotonin transporter and somatic and psychological symptoms of irritable bowel syndrome

Abstract

Objective To explore the correlation of the expression of serotonin transporter (SERT) at mRNA and protein level with psychological and somatic symptoms of irritable bowel syndrome (IBS).Methods A total of 254 out-patients of the Department of Gastroenterology were selected as case group,and 120 healthy persons and volunteers were set as control group. The expression of SERT at mRNA level was tested by real-time polymerase chain reaction (PCR) and the expression of SERT at protein level was detected with Western blotting. The study objects were evaluated by psychological and somatic symptom self-rating scale (SLC-90) and the correlation between the expression of SERT at protein level and psychological symptoms was explored.Results There were constipation irritable bowel syndrome (C-IBS),diarrhea irritable bowel syndrome (D-IBS)and alternating diarrhea and constipation irritable bowel syndrome (A-IBS).The expressions of SERT at mRNA and protein level in C-IBS (0.58±0.24;0.99±0.51) were significantly higher than those in A-IBS group (0.37±0.22;0.67±0.34),D-IBS group (0.41 ±0.26 ;0.71±0.41) and control group (0.42±0.29;0.78±0.47) (P＜0.05),there was no significant difference between A-IBS and D-IBS (P ＞ 0.05). There was negative correlation between SERT expression at protein level and psychological symptoms (r=-0.67,P＜0.01),depression factor (r=-0.81,P＜0.01),anxiety factor (r=-0.72,P＜0.01) and hostility factor (r=-0.66,P＜0.01).There was no correlation between SERT expression and interpersonal sensitivity,obsessive-compulsive symptoms,terror,paranoia and psychological factors (P＞0.05).Conclusions The expressions of SERT at mRNA and protein level in colonic mucosa may affect psychological and somatic symptoms of IBS patients.The higher SERT expressions at mRNA and protein level,constipation may be more susceptible.However the lower SERT expression at protein level,more emotional performance of somatization,anxiety,depression and hostility may be shown. Key words: Irritable bowel syndrome; Membrance transport proteins; Constipation; Anxiety; Depression