[Pharmacological analysis of the inhibition of peristalsis of the isolated guinea-pig ileum by tetramethylammonium].

Tetramethylammonium in small concentrations contracted the longitudinal muscle of the guinea-pig isolated ileum, but had no effect on the peristaltic reflex. However, in high concentrations, it contracted the longitudinal muscle and blocked the peristaltic reflex. Acetylcholine, methacholine, carbachol, eserine and neostigmine antagonized the peristaltic block previously produced by tetramethylammonium. On the other hand, propionylcholine, butyrylcholine, nicotine, pilocarpine, arecoline, histamine and 5-hydroxytryptamine did not remove the peristaltic block. From these experiments, it is concluded that the predominant sites of the depressive effect of tetramethylammonium on the peristalsis are the cholinoceptive ganglia of myenteric plexus subserving the peristaltic reflex of guinea-pig isolated ileum.