On the nature of the rhythmic contractions in the stomach and intestine

Abstract

Rhythmic contractions in the stomach and intestine persist following the administration of nicotin in doses sufficient to prevent conduction through synapses. Attempts to account for these contractions solely as responses to nervous impulses have resulted in confusion. Certain experimental data recorded by Magnus ('05), 1 Gunn and Underhill ('14), 2 and Alvarez and Mahoney ('22) 3 indicate clearly that excised pieces of the intestinal musculature may execute rhythmic contractions in the absence of nervous influences. The present paper embodies a preliminary statement of the results of a further investigation, through the use of nicotin in massive doses, of the rhythmic contractions both in the stomach and intestine in intact animals (dog).

Nicotin hydrochloride was administered intravenously in successive gradually increasing doses. Artificial respiration was employed as early as necessary and throughout the rest of the experiment.

Nicotin hydrolchloride was administered intravenously in successive gradually increasing doses. Artificial respiration was employed as early as necessary and throughout the rest of the experiment. Segmental contractions in the small intestine, peristalsis in the stomach, rhythmic contractions of the pyloric sphincter, and antiperistalsis in the large intestine continued after the administration of sufficient nicotin to abolish all responses either to electrical stimulation of postganglionic sympathetic fibers or the administration of adrenalin in relatively large doses (0.01 to 0.025 mg. per kg. of body weight). At this time the administration of adrenalin brought about no change in blo'od pressure. It was found necessary in order to secure these results, to administer approximately three grams of nicotin hydrochloride per kilogram of body weight. If now sufficient time was allowed without the administration of more nicotin the conducting mechanism recovered to such an extent that responses were again elicited by electrical stimulation of postganglionic sympathetic fibers or the administration of adrenalin in moderate doses.