The effect of temperature on end-plate depolarization of the rat diaphragm produced by suxamethonium and acetylcholine

Abstract

Abstract End-plate depolarization in the rat isolated diaphragm by suxamethonium and acetylcholine was measured at 37° and 20° using a modification of the method of Fatt (1950). At 20° the response of the motor end-plates to the depolarizing activity of acetylcholine and suxamethonium was enhanced. Since the presence of neostigmine in the bath fluid did not modify the response of the motor end-plates to the depolarizing activity of suxamethonium at 37°, the results suggest the enhanced response of the motor end-plates at 20° is due to a change in the properties of the motor end-plate, and not to a change in the activity of cholinesterases present in the tissues.