Unusual effects of the ionophore A23187 at suboptimal concentrations in mast cell histamine release

Abstract

Certain peculiarities are observed in connection with histamine release induced by suboptimal concentrations of the ionophore A23187. The potency of the ionophore can increase by a factor of 3 when added to the incubation medium from solutions in either DMSO or buffer without added calcium as compared with addition from standard buffer. The effect was not due to the solvent per se but may relate to physicochemical conditions facilitating the ionophore's access to cellular domains.