EFFECTS OF PHYSOSTIGMINE AND DUVADILAN ON AN ATROPINE-RESISTANT CONTRACTION OF DOG'S STOMACH

Abstract

Effects of atropine, physostigmine, duvadilan and tetrodotoxin on the mechanical activity of the longitudinal muscle preparation of dog's stomach in vitro experiments and on the motility of stomach in the same animal in vivo experiments were investigated.
1. The latency of an atropine-resistant contraction which was produced by stimulation of vagus nerve was increased in period in accordance with the augmentation of concentration of atropine in vitro experiments.
2. Physostigmine reconstructed the atropine-resistant contraction which was abolished by duvadilan as well as the cholinergic contraction which was abolished by atropine in vivo experiments.
3. Duvadilan abolished the cholinergic and atropine-resistant contractions in vitro, but in vivo experiments duvadilan abolished only the atropine-resistant contraction.
4. An atropine-resistant contraction was completely abolished by administration of tetrodotoxin. But the direct electrical stimulation of the muscle caused the contraction of it which was blocked by tetrodotoxin.