An electrophysiological study of the effects of ionophore A23187 on Nauphoeta salivary glands.

The ionophore A23187 produces a hyperpolarization of cockroach salivary gland cells in the presence or absence of added calcium ions. The effect is greater and more prolonged in the presence of calcium and is dependent on the external potassium ion concentration. It is proposed that the ionophore can increase the intracellular calcium ion concentration by an increase in influx from the external medium or by mobilization of intracellular calcium stores and that this results in an increase in the potassim permeability, thus producing a hyperpolarization.