Methamphetamine‐Induced Changes in Antioxidant Enzymes and Lipid Peroxidation in Copper/Zinc‐Superoxide Dismutase Transgenic Mice

ABSTRACT: The present study was conducted to investigate the effects of methamphetamine (METH)‐induced toxicity on brain cortical and striatal antioxidant defense systems. Because METH‐induced toxicity is attenuated in copper/zinc‐superoxide dismutase transgenic (Cu/Zn‐SOD‐Tg) mice, we sought to determine if METH had differential effect on antioxidant enzymes on these mice in comparison to non‐Tg mice. METH (4 × 10 mg/kg) induced a significant decrease in Cu/Zn‐SOD activity in the cortical region without altering striatal enzymatic activity in non‐Tg mice; whereas homozygous SOD‐Tg mice showed a significant increase in the striatum. In addition, METH caused decrease in catalase (CAT) activity in the striatum of non‐Tg mice and significant increase in the cortex of homozygous SOD‐Tg mice. METH also induced decreases in glutathione peroxidase (GSH‐Px) in both cortical and striatal regions of non‐Tg mice and in the striatum of heterozygous SOD‐Tg mice. Lipid peroxidation was increased in both cortices and striata of non‐Tg and heterozygous SOD‐Tg mice, whereas the homozygous SOD‐Tg mice were not affected. These results are discussed in terms of their substantiation of a role for oxygen‐based radicals in METH‐induced toxicity in rodents.