THE EFFECTS OF ACETYLCHOLINE AND ESERINE ON FROG MUSCLE

Abstract

The effects of eserine, curare and acetylcholine on the normally circulated frog''s gastrocnemius subjected to varying frequencies of indirect stimulation were studied. Lymph-sac injs. of eserine produce a potentiation of single twitches. Slow frequencies, after eserine, produce responses similar to those seen at higher frequencies in the normal muscle. After curare, the frequency required to produce maximal tension increases. The antagonism between curare and eserine is readily demonstrated. Short tetani at various frequencies result in a temporary decurarization. After a depressant arterial inj. of acetylcholine, subsequent injections have greater effects. Acetylcholine, after curare, may have either a depressant or a decurarizing action or, in unusual cases, a combination of both effects.