Assessment of Oxidative Damage Induced by Acute Doses of Morphine Sulfate in Postnatal and Adult Rat Brain

The aim of the present study is to evaluate the oxidative damage in rats of different ages. Weaned rats of 25 g and adults of 300 g were used in groups of 6, a single i.p. dose of morphine sulfate of 3, 6 or 12 mg/kg was administered. All animals were sacrificed to measure GSH and 5-HT levels in brain by liquid chromatography, as well as Na+, K+-ATPase and total ATPase enzymatic activity. 5-HT levels decreased significantly (p<0.05) in adult animals that received 3 and 6 mg morphine. Na+, K+-ATPase activity increased significantly (p<0.05) in all groups of weaned animals. In adult animals, Na+, K+-ATPase and total ATPase partially diminished. GSH levels diminished significantly (p<0.05) both in weaned and in adult groups. The results indicate age-induced changes in cellular regulation and biochemical responses to oxidative stress induced by morphine.