Nervous control of intestinal motility in gold fish (author's transl)

Abstract

The mechanical activities and innervation of the intestinal bulb of the gold fish were investigated by pharmacological and histochemical techniques.The mechanical responses of the intestinal bulb to the transmural stimulation could be classified into three different components; (1) initial rapid contraction, (2) relaxation, (3) late slow contraction. The initial rapid contraction was inhibited by dTc or by tetrodotoxin (TTX). The relaxation was inhibited by TTX but not inhibited by guanethidine. Thelate slow contraction was slightly depressed by atropine. This atropine resistant contraction in late slow phase was completely inhibited by TTX.DMPP was effective to produce the initial rapid and late slow contractions which are similar to the response of transmural stimulation.The biphasic contraction, which caused by DMPP was reversed to initial relaxation and late slow contraction after the application of atropine and dTc. These relaxation and late slow contraction were inhibited by C6 or TTX.These results may suggest the presence of two types of excitatory neurogenic responses in thistissue.Histochemical observations revealed the presence of adrenergic nerve fibers within the musculature of the intestinal bulb.