[SEROTONERGIC REGULATION OF THE DUODENUM CONTRACTIONS].

The review contains an analysis of literature data on enhancement mechanisms of duodenum contractions arising during stimulation of the sympathetic trunk in the right thoracic cavity in dogs. It is established in experiments that There are mostly enhancement, not relaxation of the organ contraction occured. In this case the stimulatory effect due to the excitation of the parasympathetic fibers is excluded. The trimeperedin inhibit the serotonin receptors of autonomic ganglia neurons stimulatory activity during the nerve stimulation. It is concluded that the sympathetic trunk contain the preganglionic serotonergic nerve fibers, whose activation leads to increased bowel contractions. Direct adipinate-serotonin administration increased the bowel contraction that confirm the preganglionic serotonergic nerve fibers presence in the sympathetic trunk. The practical significance of these studies is that the new approach to the development of pharmacological agents to stimulate the motility of the gastrointestinal tract was found. The trimeperedin may inhibit the serotoninergic nerves activity that resulted in the perioperative constipation in surgical patients. Practical recommendation to exclude trimeperedin in preparing the patient for surgery to prevent perioperative constipation is formulated.

[The mechanism of inhibition of small intestine contractions following irritation of rabbit's vagus nerve]. / Mekhanizm tormozheniia sokrashchenii tonkoi kishki, voznikaiushchego pri razdrazhenii bluzhdaiushchego nerva u krolika.

Explored was mechanism of inhibition of small intestine contractions due to weak irritation (0.5-2.5 V, 1-30 Hz, 0.3-1.0 ms) of the peripheral segment of rabbit's right vagus nerve. It was shown that the inhibitory effect can be blocked by benzohexamethonium, arphonade, atropine, rhausedyl, and a combination of propranolol and dehydroergotoxine. Inhibition is triggered by catecholamines released by sympathetic endings in consequence of activation of presynaptic M-cholinoreceptors on their surface. Presynaptic M-cholinoreceptors are activated by acetylcholine released by the endings of postganglionary parasympathetic nerve fibers.