Action of veratridine on acetylcholinesterase in cultures of rat muscle cells

Abstract

Studies on cultures of embryonic rat muscle cells have suggested that the presence of collagen-tailed forms may be correlated with spontaneous contractile activity: these forms disappear in the presence of tetrodotoxin which blocks the sodium channels involved in the propagation of action potentials. The effect of veratridine, a drug which maintains the sodium channels in the open state, was studied. It is shown here that in young cultures veratridine provoked a dramatic increase in total acetylcholinesterase activity and changed the distribution of the molecular forms of the enzyme, increasing the proportion and absolute amount of the A 12 form. In order to elucidate the mechanism of action of this drug, the effects of various ions, ionophores, or other agents that modify the ionic permeabilities of membranes were also investigated.