[A pharmacological analysis of the central control of the preganglionic sympathetic neurons during stimulation of the afferent nerve fibers of the digestive tract].
In acute experiments on cats, effect of adrenergic brain neurons on impulse activity of preganglionic fibers of the left splanchnic nerve was studied. Afferent fibers of nerves innervating the stomach, duodenum, ileum and ileocecal angle were electrically stimulated. Phenoxybenzamine, obsidan, amizyl, iprazid, nuredal, dalargine, and morphine were used for pharmacological analysis. Nerves, stimulation at 20 Hz of different segments of the digestive tract was accompanied by different inhibition of preganglionic neurons. Sympathetic-stimulating effects were observed more frequently at 5 Hz stimulation. After vagotomy, alpha- and beta-adrenoreceptor block, central cholinoreceptor and monoamine oxidase (MAO) block, and after dalargine (0.1 and 0.01 mg/kg) nerves stimulation at 20 Hz was followed by sympathetic-stimulating effect. A weak regulatory effect of morphine (1 and 10 mg/kg) on ileal nerve stimulation effects was shown. It is suggested that excitation from afferent neurons of the vagus is transmitted to central cholinergic neurons which, in their turn, excite adrenergic neurons of the brain, and the latter inhibit impulsation of preganglionic fibers. MAO block increased the balance of excitatory effect of serotonin on spinal reflexes. Morphine and dalargine intracentrally may block adrenergic and cholinergic transmissions, as well as decrease the release of substance P from afferent neurons. Their regulatory action is revealed when different frequencies of stimulation are used.
Itina
L V
LV
Posniak
V A
VA
D000344:Afferent Pathways / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000187:drug effects* / Q000502:physiology; D002415:Cats; D004064:Digestive System / Q000187:drug effects* / Q000294:innervation*; D004068:Digestive System Physiological Phenomena; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D005260:Female; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D013268:Stimulation, Chemical
Farmakologicheskiĭ analiz tsentral'nogo kontrolia preganglionarnykh simpaticheskikh neĭronov pri razdrazhenii afferentnykh volokon nervov pishchevaritel'nogo trakta.