Inhibition of rat hepatic microsomal lipid peroxidation by mesna via glutathione

Glutathione (GSH, 1 mmol/l) inhibits Fe2+/ascorbic acid induced liver microsomal lipid peroxidation. Oxidized GSH (GSSG, 1 mmol/l) did not affect rate or extent of lipid peroxidation. The inhibition by GSH seems specific since the sulfhydryl agent sodium 2-mercaptoethanesulfonate (mesna) gave a slight stimulation of lipid peroxidation. This stimulation is probably explained by a reduction by mesna of dehydroascorbic acid which is formed during the incubation, into ascorbic acid. Remarkably, mesna (1 mmol/l) added together with GSSG (1 mmol/l) produced the same inhibition as with 1 mmol/l GSH alone. This can be explained by direct reduction of GSSG to GSH by mesna. This is corroborated in experiments in which GSH is measured directly. Dimesna did not show an effect on lipid peroxidation. In the protective action of mesna against reactive substances its ability to reduce GSSG should be appreciated.