Experimental Study of the Vagus Nerve upon Action Potential of the Gastrointestinal Tract

Report I.Effect of the Vagotomy upon the Action Potential of Gastrointestinal Tract<BR>Electromyographic study of the gastrointestinal tract were performed in dogs pre-operatively, immediately after vagotomy, one day, 3 days, 7 days and 14 days after the operation.Recording were done under the following way.The dogs were anesthetized with nembutal and action potential were introduced directly from serous membrane of the stomach body, pylorus, duodenum, ascending and descending colon with bipolar electrodes simulaeoustaneously.The data obtained from the analysis of the spike wave, number of spikes, appearance of the burst and number of spike groups in every minute.<BR>The resurt obtained were as follows:<BR>1. Total number of spikes in a minutes decreased in duodenum after vagotomy and the depressing effect was the highest in duodenum but the temporary accererative effect after vagotomy were observed in pylorus.<BR>2. Number of the spike groups appearing in a minute were devided approximately into three groups.In stomach and pylorus it was 5 times, in duodenum and ileum, 16 times and 8 times in ascending and descending colon.The order of the number of grouping were not altered after vagotomy.<BR>3. Spike burst of G. I.tract decreased after vagotomy.Until 7 days after operation, it showed mild tendency of recovery but after operation 14 days it disappeared or remarkably depressed in all G. I.tract except stomach body.<BR>4. Effect of vagotomy were observed more in the upper G. I.tract but lesser in the lower G.I.tract.<BR>Report II. Effect of the tow Drugs upon the Action Potential in Gastrointestinal Tract before and after Vagotomy<BR>The above mentioned recording proceedure were performed in order to study the effect of sympathethic stimulants and depressants upon gastrointestinal tract.Imidalin and Ephedrine wers selected as a sympathetic stimulants and depressing drugs.Recording of the E.M.G.were done in the same days as report 1.pre-and post-operatively.<BR>1. Accelerating effect with Imidalin, and depressing effect of Ephedrine upon potential after vagotomy were observed until 7 days after the operation but 14 days postoperatively these drugs did not show significant effect upon the G.I.tract.<BR>2. Depressing effect of Ephedrine upon G.I.tract action potential were observed in the highest degree in pylorus in every period.<BR>3. Accerarating effect of G.I.tract action potential following depressing effect of Ephedrine were observed in every period.<BR>4. Depressing effect of Ephedrine is prevalent to the accererating effect of Imidaline after vagotomy.