V.I. Torshin, D.S. Sveshnikov, V.M. Smirnov, A.V. Kuchuk

This study is determined the role of 5HT2-receptors in excitatory responses of the duodenum to exogenous serotonin in Wistar rats. Experiments were performed under general anesthesia, me-chanical ventilation, bilateral vagotomy and bilateral transection of the glossopharyngeal nerve. Mechanical activity of the duodenum was recorded during serotonin adipate infusion to intact an-imals and on the background of the ongoing actions of cholinergic, adrenergic antagonists and SB 204741 - the selective blocker of 5-HT2b-receptors. Simultaneous blockade of adrenergic and cho-linergic receptors does not prevent, but amplify stimulatory effect of serotonin. 5-Ht2b receptor blockade eliminates excitatory reactions. Concluded that serotoninergic structures exerted their control influence by 5-HT2b-receptors.