Regional distribution of superoxide dismutase in rat brain during postnatal development.

Superoxide dismutase in nervous system protects readily oxidizable compounds such as catecholamines against toxic effects of oxygen. We investigated superoxide dismutase activity during development in 5 brain regions selected for a wide range of catecholamine concentration and turnover: cerebellum, neocortex, striatum, hypothalamus and medulla-pons. The cytosolic and the particulate enzyme were measured from birth to 6 months of age. In cerebellum the cytosolic enzyme shows considerable activity on the first postnatal days; the particulate enzyme is less active, both reach a maximum at 3 months. In cortex and striatum both activities were low during the postnatal days and reach a plateau at 3 months. In hypothalamus both activities are higher during the postnatal days and reach a maximum at 3 months. In medulla-pons the values are 2 times higher than in all other regions; the cytosolic enzyme reaches a maximum at 2 months whereas the particulate enzyme reaches a plateau at 3 months. Thus our results show an increase of superoxide dismutase activity during development in all brain regions; the highest activities were found in regions with high catecholamine content.