标题：Chemicopharmacological Studies on Antispasmodic Action. VIII. On the Antagonistic Action of Atropine and its Methobromide to Acetylcholine with the Isolated Small Intestines of Mice.
摘要：(1) The after-effect of Atr tends to increase the contractibility of samll intestines in mice to ACh. (2) The log concentration-action curves of ACh were obtained under a constant concentration of Atr. There was no depression of the maximum at each Atr. The reaction order n between ACh and its receptor was not changed significantly from 1. These results indicate the competitive nature of antagonism between ACh and Atr. (3) The estimate of n was not significantly different from 1.5 according to our results on the concentration-inhibition curve of Atr against a constant concentration of ACh. (4) By means of the log concentration-inhibtion curve of Atr-MeBr, the mode of action was shown to be competitive, the same as Atr, and the estimate of n was not significantly different from 1.5, either. The former has a little more effect than the latter.
