Superoxide production and the activity of MnSOD in rat brain after intrahippocampal kainate-induced seizure

Abstract

Glutamate neurotoxicity has been hypothesized to underlie several types of acute brain injury. Free radical reactions are implicated in a variety of physiological and pathological processes and abnormalities associated with superoxide dismutase (SOD) have been recently documented in several neurodegenerative processes. We investigated superoxide production and MnSOD activity after kainate injection into the CA3 region of the rat hippocampus. The measurements take place at different times in the hippocampus, forebrain cortex, straitum and cerebellum homogenates. Free radicals including superoxide are responsible for postlesional cytotoxicity. The increase of MnSOD in distinct brain regions, which are functionally connected via afferents and efferents, suggests that these regions are affected by the injury. It suggests that MnSOD protects the cells in these regions from superoxide-induced damage and therefore may limit the retrograde and anterograde spread of neurotoxicity.