EFFECT OF OXIDATIVE STRESS ON (H-3)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 H2O 2 or FeSO4 and ascorbic acid, on binding properties of muscarinic rece ptors in rat cerebral cortex membranes. Simultaneously the concentrati ons of thiobarbituric acid reactive substances (TBARS) were measured t o assess the extent of lipid peroxidation. In conditions of increased TBARS levels the density of (H-3)N-methylscopolamine [(H-3)NMS] bindin g sites in rat cerebral cortex membranes was not affected. Decreased n umbers of (H-3)NMS binding sites observed in the presence of high conc entrations of H2O2 (100 and 1000 mmol.l-1) accompanied by a decrease o f TBARS levels might be related to a nonspecific effect of H2O2 on cel lular proteins.