The Action of Ephedrine on Melanophores.

Abstract

Nadler1 found that in the squid, Loligo pealii, ephedrine injected subcutaneously, produced a local blanching which was considered as due to an inhibition of the smooth muscle of the chromatophore system and a generalized reddish coloration ascribed to a stimulation of the central nervous system. These experiments have been repeated on several other kinds of fish, namely Cyprinus rubrofuscus, Mylopharyngodon aethiops, Cyprinus abbreviatus and Ophiocephalus argus and they all responded by a generalized paleness. Examination of the scales showed that all the melanophores were contracted. One fish remained in such state for 36 hours. It appears therefore that, in the fresh water fish studied, ephedrine does not exert a double action, or both the peripheral and the central actions bring about a similar change, namely contraction of the black pigment cells. Experiments with adrenalin appear to substantiate the latter view, since this drug caused only a local blanching and no generalized paleness of the scales....