Inhibition of hepatocyte plasma membrane Ca²⁺‐ATPase activity by menadione metabolism and its restoration by thiols

Abstract

Incubation of isolated rat hepatocytes with cytotoxic concentrations of menadione resulted in inhibition of plasma membrane Ca2+-ATPase activity. This could be restored by subsequent treatment with either dithiothreitol or reduced glutathione, suggesting that the inhibition by menadione was due to oxidation of sulfhydryl groups critical for Ca2+-ATPase activity.