Clinical Research
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Mar 14, 2006; 12(10): 1591-1596
Published online Mar 14, 2006. doi: 10.3748/wjg.v12.i10.1591
Effect of 5-HT1 agonist (sumatriptan) on anorectal function in irritable bowel syndrome patients
Agata Mulak, Leszek Paradowski
Agata Mulak, Leszek Paradowski, Department of Gastroenterology and Hepatology, Wroclaw Medical University, Wroclaw, Poland
Author contributions: All authors contributed equally to the work.
Supported by the grant from GlaxoSmithKline Pharmaceuticals S.A.
Correspondence to: Agata Mulak, MD, PhD, Department of Gastroenterology and Hepatology, Wroclaw Medical University, Poniatowskiego 2, 50-326 Wroclaw, Poland.
Telephone: +48-71-3229918 Fax: +48-71-3224401
Received: September 8, 2005
Revised: October 1, 2005
Accepted: November 18, 2005
Published online: March 14, 2006

AIM: To evaluate the effect of sumatriptan, a selective 5-HT1 agonist, on anorectal function in irritable bowel syndrome (IBS) patients.

METHODS: Twenty-two IBS patients selected according to the Rome II criteria (F 15, M 7; mean age 29.3±6.8, range 22-44 years) were examined. The study was blind, randomized and placebo-controlled with a crossover design. Anorectal manometry and rectal balloon distension test were performed before and after the administration of placebo and sumatriptan.

RESULTS: The administration of sumatriptan caused a significant increase in the resting anal canal pressure from 9.2±2.0 kPa to 13.1±3.3 kPa (P<0.0001) connected with the increase in the anal sphincter length and high pressure zone. After sumatriptan injection a remarkable increase in the threshold for the first sensation from 27±9 mL to 34±12 mL (P<0.05) and urge sensation from 61±19 mL to 68±18 mL (P<0.01) was observed. Sumatriptan did not affect either the volume evoking the rectoanal inhibitory reflex or the results of the straining test.

CONCLUSION: 5-HT1 receptors participate in the regulation of anorectal function. Elucidation of the role of 5-HT1 receptors in the pathophysiological mechanisms of IBS may have some therapeutic implications.

Keywords: Sumatriptan, 5-HT receptors, Irritable bowel syndrome, Anorectal function