Effect of 5-HT1 agonist (sumatriptan) on anorectal function in irritable bowel syndrome patients.
OBJECTIVE
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.


CONCLUSIONS
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.
Department of Gastroenterology and Hepatology, Wroclaw Medical University, Poniatowskiego 2, 50-326 Wroclaw, Poland. agata.mulak@wp.pl
Agata
A
Mulak
Leszek
L
Paradowski
D000328:Adult; D001003:Anal Canal / Q000187:drug effects* / Q000502:physiology; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008365:Manometry; D012007:Rectum / Q000187:drug effects* / Q000502:physiology; D017366:Serotonin Receptor Agonists / Q000627:therapeutic use*; D018170:Sumatriptan / Q000627:therapeutic use*
D017366:Serotonin Receptor Agonists; D018170:Sumatriptan