ACTIVATION OF IRON HANDLING-SYSTEM WITHIN THE GERBIL HIPPOCAMPUS AFTER CEREBRAL-ISCHEMIA

Analyzing the distribution pattern of transferrin (Tf) and ferritin, w e investigated the changes in iron metabolism related proteins in the process of neuronal death induced by 5 min ischemia. In the control an imals, Tf immunoreactivity was localized in the oligodendrocytes. Ferr itin was distributed in both neurons and gliacytes, particularly micro glia. In parallel with the delayed neuronal death, Tf-positive atrophi ed neurons and numerous ferritin-positive gliacytes appeared in the CA 1 subfield of the hippocampus 4 days after ischemia, when glia fibrill ary acidic protein (GFAP)-positive astrocytes also appeared throughout the hippocampal structure. A considerable number of ferritin-positive phagocytes (reactive microglia) appeared in the stratum pyramidale fr om the seventh day. Our data show clearly that the mobilization of Tf and ferritin-positive phagocytes are linked with the degeneration of n eurons induced by cerebral ischemia. These events may suggest an activ ation of iron handling system under the postischemic condition.