Salicylate-induced cation fluxes across biological membranes. A study of the underlying mechanism.

The effect of salicylate on cation transport by lactating rat mammary tissue has been examined. Consistent with previous results, salicylate increased the unidirectional efflux of K+ (Rb+): this increase was dependent on extracellular Ca2+. Lowering the temperature of the incubation medium from 37 degrees to 4 degrees did not attenuate the effect of salicylate on K+ (Rb+). Ca2+ uptake by mammary tissue was stimulated by salicylate, whereas Ca2+ efflux was not greatly affected. Salicylate reduced the ouabain-insensitive uptake of K+ (Rb+). The net K+ content of mammary tissue was reduced by incubating tissue in a medium containing salicylate, whereas net Na+ content was increased. The results are consistent with the hypothesis that salicylate activated a calcium-dependent K+ efflux channel and/or a calcium-dependent non-selective cation channel.