Lipid peroxidation and antioxidant enzymes in isoproterenol induced oxidative stress in rat erythrocytes.

Isoproterenol, upon oxidation, produces quinones which react with oxygen to produce superoxide anions (O2.-) and H2O2. In the present study, isoproterenol was administered to rats in two doses so as to evaluate its beta adrenergic and toxicological action in terms of lipid peroxidation (LPO) and antioxidant enzymes in erythrocytes. Isoproterenol (30 mg/100 g body wt.) was administered to rats and the animals were followed up to 7 days after administration. Some of these animals were treated with a second dose of isoproterenol 24 h after the first dose and the animals were followed up to 12 h. The result showed increased lipid peroxidation (LPO) and superoxide dismutase (SOD) activity in erythrocytes in response to isoproterenol. Catalase (CAT) activity in erythrocytes decreased with isoproterenol between day 2-7 as compared to control. The second injection of isoproterenol showed increased CAT activity in erythrocytes which decreased at 12 h as compared to control. The erythrocyte GSH content and glutathione-S-transferase (GST) activity decreased with isoproterenol treatment as compared to control. However, erythrocyte GSH content as well as GST activity both recovered towards control with time. Elevated serum lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and glutamate oxaloacetate transaminase (GOT) activity was observed after isoproterenol treatment. The results show increased LPO and altered antioxidant system in erythrocytes in response to isoproterenol induced oxidative stress.