Background: Secondary peristalsis is important for the clearance of retained food bolus or refluxate from the esophagus. The effects of the gamma aminobutyric acid receptor type B (GABA(B) ) agonist on secondary peristalsis remain unclear in humans. We aimed to investigate the effect of a GABA(B) agonist baclofen on esophageal secondary peristalsis.
Methods: After a baseline recording of esophageal motility, secondary peristalsis was generated by slow and rapid mid-esophageal injections of air in 15 healthy subjects. Two separate sessions with 40mg oral baclofen or placebo were randomly performed to test their effects on secondary peristalsis.
Key results: Baclofen increased the threshold volume for triggering secondary peristalsis during slow air distension (P=0.003) and rapid air distension (P=0.002). Baclofen reduced the rate of secondary peristalsis by rapid air distension from 90% to 30% (P=0.0002). Baclofen increased basal lower esophageal sphincter pressure (P=0.03). Baclofen did not affect any of peristaltic parameters during primary or secondary peristalsis.
Conclusions & inferences: This study provides an evidence for inhibitory modulation of esophageal secondary peristalsis by the GABA(B) agonist baclofen. Activation of secondary peristalsis is probably modulated by GABA(B) receptors; however, baclofen does not lead to any motility change in secondary peristalsis.
© 2011 Blackwell Publishing Ltd.