IBS-D and SERT

The important role of serotoninin gut function is well recognized.Release of serotoninfrom the basolateral membranesof enterochromaffin cells in theepithelial lining of the gut intothe vicinity of afferent nerveendings represents the primarymethod of sensory transmissionfrom the lumen of the gastrointestinaltract. Because this signalingmechanism involves secretionof large amounts ofserotonin, the mechanism forthe uptake of serotonin (via theserotonin reuptake transporter[SERT]) must be efficient.

In a recent issue of Gut, AstridYeo, PhD, and colleagues performeda genotypic analysis on194 women with irritable bowelsyndrome with diarrhea (IBS-D)and 448 controls. Results of polymerasechain reaction analysisexamining 9 SERT polymorphisms,including the insertion/deletion polymorphism inthe SERT promoter (SERT-P) andthe variable tandem repeat inintron 2, demonstrated a stronggenotypic association between theSERT-P deletion/deletion genotypeand the presence of IBS-D.