The cardiac action of lysolecithin.

L-α-lysolecithin was prepared from egg lecithin by the action of snake venom phospholipase A. This lysolecithin was found to produce positive inotropic and chronotropic effects in isolated preparations of guinea-pig, rat and rabbit heart. These effects were antagonized by the beta -adrenergic receptor blocking agent, pronethalol, and were absent in preparations from animals pretreated with reserpine. The sensitivity of the three species to the effects of lysolecithin was found to be in the order guinea pig > rat > rabbit. It is concluded that the effects of lysolecithin on the heart are the result of catecholamine release and are not due to a digitalis-like action.