Effect of oxidative stress on (3H)N-methylscopolamine binding and production of thiobarbituric acid reactive substances in rat cerebral cortex membranes.

We investigated the effect of lipid peroxidation, in vitro induced by H2O2 or FeS04 and ascorbic acid, on binding properties of muscarinic receptors in rat cerebral cortex membranes. Simultaneously the concentrations of thiobar­ bituric acid reactive substances (TBARS) were measured to assess the extent of lipid peroxidation. In conditions of increased TBARS levels the density of ( 3H)N- methylscopolamine (( 3H)NMS) binding sites in rat cerebral cortex membranes was not affected. Decreased numbers of ( 3H)NMS binding sites observed in the pre­ sence of high concentrations of H2O2 (100 and 1000 mmol.l"1) accompanied by a decrease of TBARS levels might be related to a nonspecific effect of H2O2 on cellular proteins.