Subcellular localization of superoxide dismutases, glutathione peroxidase and catalase in developing rat cerebral cortex.

The levels of copper- and zinc-containing superoxide dismutase (CuZnSOD), manganese-containing superoxide dismutase (MnSOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activity have been assessed in a nuclear fraction (NF), a mitochondrial fraction (MF) and a non-mitochondrial, non-nuclear fraction (NMNNF) isolated from developing rat cerebral cortex. The NF showed increasing CuZn and MnSOD activities and static, low activities of GSH-Px and CAT during development. The MF had increased levels of MnSOD and GSH-Px activities and a rapid decrease in CAT activity associated with development. Histochemical methods have localized greater CAT activity in mitochondria isolated from 2-day-old rat brain when compared to 77-day-old animals. Development was associated with increasing CuZnSOD activity, a decrease in CAT activity and, after an initial fall at 19 days, increasing GSH-Px activity in the NMNNF. Measurable activity of MnSOD were found in the NMNNF and appeared to be static during the time period assessed. A distinct ontogenetic pattern of oxidative enzyme activities and subcellular locations is associated with development in rat cerebral cortex.