Abstract
Utilizing Trendelenburg's as well as Magnus' method the influence of TTFD upon the movement of the isolated small intestine of guinea pigs, rabbits, cats and dogs were studied. The results were summarized as follows : (1) At the concentration of 5 × 10^<-5> g/ml TTFD produced, on the one hand, a lowering of the tone, prolongation of the period of rhythmic contraction waves and on the other hand, a remarkable increase of the amplitude of the waves. (2) After the administration of atropine, the excitatory effect of TTFD was reversed to the inhibitory. (3) After successive administrations of atropine and hexamethonium, no action of TTFD was remarked. (4) TTFD had no effect on the small intestine isolated from cats treated with reserpine and atropine. (5) From the results described above, it may be concluded that TTFD exerts an exciting action upon both the excitatory and inhibitory neurones residing in Auerbach's plexus, whereas it exerts no action upon the intestinal muscle. It could be considered that the effects described in (1) were the results of a mutual coordination of the function of two kinds of neurones described above.
