Effect of sulfhydryl reagents on k efflux from rose cells: relationship to ultraviolet-stimulated efflux.

N-Ethylmaleimide causes a rapid efflux of K(+) from suspension-cultured cells of Rosa damascena. This efflux shows many characteristics of the ultraviolet-induced efflux of K(+), including the appearance of HCO(3) (-) together with the K(+) and inhibition by respiratory inhibitors. Cysteine inhibits the ultraviolet-induced efflux of K(+). These results are interpreted to mean that ultraviolet induces K(+) efflux through an alteration of sulfhydryl residues.