Demonstration of Cu-Zn superoxide dismutase in rat liver peroxisomes. Biochemical and immunochemical evidence.

In this study, by using highly purified rat liver peroxisomes, we provide evidence from analytical cell fractionation, Western blot, and immunocytochemical analysis that Cu-Zn superoxide dismutase is present in animal peroxisomes. Treatment with ciprofibrate, a peroxisome proliferator, increased the peroxisomal superoxide dismutase activity by 3-fold with no effect on mitochondrial activity but a marked decrease in cytosolic superoxide dismutase activity, further supporting that besides cytosolic and mitochondrial localization, Cu-Zn superoxide dismutase is present in peroxisomes also. Demonstration of superoxide dismutase in peroxisomes suggests a new role for this organelle in pathophysiological conditions, such as ischemia-reperfusion injury.