Published online Mar 28, 2015. doi: 10.3748/wjg.v21.i12.3509
Peer-review started: October 6, 2014
First decision: October 29, 2014
Revised: November 6, 2014
Accepted: December 1, 2014
Article in press: December 1, 2014
Published online: March 28, 2015
Core tip: Entacapone, a catechol-O-methyltransferase (COMT) inhibitor, is an emerging drug for Parkinson’s disease (PD) patients. However, patients experience gastro-intestinal side effects with entacapone treatment and the reason for this is unknown. This study for the first time proved that COMT is expressed in normal and PD rat colons and that entacapone can inhibit PD rat muscle contraction through the β2 adrenoceptor. It was also discovered that entacapone can induce cAMP-dependent Cl- secretion in PD rats and that endogenous prostaglandin is involved in this process. These findings provided histological evidence of COMT in the colon, establishing an experimental basis for the mechanism of entacapone-induced PD gastro-intestinal side effects.