Action of Acetone on the Tonic Muscle of the Frog

Abstract

ACETYLCHOLINE added to Ringer solution in which m. rectus abdominis of the frog (Rana temporaria) is immersed causes the well-known acetylcholine contracture of the muscle. The magnitude of this shortening depends on the functional state of the muscle, the concentration of acetylcholine, the temperature of the bath, and on the constituents of the medium surrounding the muscle. Many agents which increase the acetylcholine activity or, when present alone, induce a shortening of the m. rectus, have been described. Some of these, according to their mode of action, can be used for sensitizing biological acetylcholine titration. In some cases this effect can be explained by the inhibition of cholinesterases present in the muscle. According to Torda¹ and Hsi Chung Chang et al. ² acetone is also included in this group.