COPPER-ZINC SUPEROXIDE-DISMUTASE AND ISOLECTIN B-4 BINDING ARE MARKERS FOR ASSOCIATIVE AND TRANSHEMISPHERIC DIASCHISIS INDUCED BY FOCAL ISCHEMIA IN RAT CORTEX

Copper/zinc-superoxide dismutase (Cu/Zn-SOD) belongs to a class of enz ymes, identified as essential and highly effective endogenous scavenge rs of cytotoxic oxygen radicals. These radicals contribute to postlesi onal neurotoxicity. In order to determine the superoxide-scavenging po tential of regions affected by unilateral cortical photothrombosis, we studied the changes in the distribution of Cu/Zn-SOD and the appearan ce of activated microglia by immunohistochemistry and isolectin Bq bin ding. Four hours postlesion, Cu/Zn-SOD increased significantly within a homotopic area of the contralateral hemisphere and in ipsilateral th alamic nuclei, whereas isolectin Bs-positive microglia were upregulate d at days 5 and 7 postlesion within the same regions. The contralatera l increase in the amount of the superoxide-scavenging Cu/Zn-SOD indica tes that this enzyme is induced by a retrograde reaction carried throu gh callosal connections. (C) 1997 Elsevier Science Ireland Ltd.