The Action of Drugs, Especially Acetylcholine, on the Annelid Body Wall (Lumbricus, Arenicola)

Abstract

1. The actions of certain drugs (acetylcholine, eserine, atropine, nicotine, adrenaline) on strips of the body wall of the earthworm (Lumbricus terrestris) and lugworm (Arenicola marina) are described. 2. The body wall of the earthworm and lugworm resembles the dorsum of the leech, and also vertebrate skeletal muscle, in the following points: relatively insensitive to acetylcholine alone, sensitivity to acetylcholine greatly increased by eserine, response to acetylcholine abolished by nicotine. In these points, the muscles mentioned contrast with the earthworm gut and the mammalian intestine, which are: very sensitive to acetylcholine alone, sensitivity not greatly increased by eserine, response to acetylcholine abolished by atropine. 3. The various types of body wall strip differ among themselves as regards spontaneous activity, response to eserine alone, and response to adrenaline.

The Effect of Physostigmine on the Responses of Earthworm Body Wall Preparations to Successive Stimuli

“…An investigation of the muscular responses of the earthworm body wall is of especial interest since this muscle seems to parallel vertebrate striated muscle in some of its physiological characteristics. Certain of these similarities have been referred to by Pantin (1935b) and by Wu (1939).…”

“…worm body wall muscles, application of physostigmine was tried. Wu (1939) has shown that the sensitivity of the body wall to acetylcholine is greatly increased by physostigmine. From the results of his experiments concerning the action of drugs on the earthworm body wall, he postulated the presence of some factor which prevented the action of acetylcholine and which was antagonized by physostigmine.…”