The expression and effect of 5-hydroxytryptamine 7 receptor in brain and intestine of rats with irritable bowel syndrome / 中华消化杂志

ABSTRACT

Objective To investigate the expression and distribution of 5-hydroxytryptamine 7(5-HT7)receptor in brain and intestine of rats with different subtype of irritable bowel syndrome(IBS).Methods Forty-five SD rats were divided into healthy contral.diarrhea-predominant(IBS-D)and consti pation-predominant(IBS-C)IBS groups.IBS-D and IBS-C models were established by either colonic instillation of acetic acid and restraint stress or stomach irrigation with cool water(0-4℃).The expression and distribution of 5-HT7 receptor at brain and intestine were determined by immunohistochemistry and real-time PCR.The tissue concentration of cyclic AMP(cAMP)was examined by radioimmunoassay.Results Immunohistochemistry study demonstrated that the staining of 5-HT7 receptor at hippocampus and hypothalamus were strong in IBS-C and IBS-D groups compared to control group(P＜0.01),The staining of 5-HT7 receptor at ileum,proximal colon and distal colon were higher in IBS-C group than those in control group(P＜0.05).Real-time PCR revealed that the expression of 5-HT7 receptor at hippocampus and hypothalamus were higher in IBS-C and IBS-D groups than those in control group(P＜0.05).and the expression at ileum and colon were remarkably higher in IBS-C group compared to control group(P＜0.05).The concentration of cAMP at hippocampus and hypothalamus were higher in IBS-C and IBS-D groups than those in control group(P＜0.01,P＜0.05).The cAMP level at proximal and distal colon in IBS-C group was higher than those in control group(P＜0.05).Conclusion The upregulation of 5-HT7 receptor in brain and intestine may be related with the dyskinesis and visceral paresthesia of IBS-C.