Characteristics of evodiamine-exerted stimulatory effects on rat jejunal contractility

This study was designed to characterise the effects of evodiamine on intestinal contractility and reveal the correlated mechanisms. Evodiamine (2.5–80.0 μM) increased normal jejunal contractility and jejunal hypocontractility established under a variety of experimental conditions. Evodiamine-exerted stimulatory effects were blocked by the L-type Ca2+ channel blocker nifedipine or abolished in the Ca2+-free assay condition. The stimulatory effects of evodiamine on jejunal contractility were partially blocked in the presence of neurotoxin tetrodotoxin or endogenous acetylcholine synthesis blocker hemicholinium-3 or muscarinic receptor antagonist atropine, respectively. Evodiamine-exerted stimulatory effects were blocked by c-kit receptor tyrosine kinase inhibitor imatinib. Evodiamine increased myosin phosphorylation in jejunal smooth muscle of constipation-prominent rats. These results showed that evodiamine-exerted stimulatory effects on jejunal segments are Ca2+-dependent, need the presence of interstitia...