Glial expression of the beta-amyloid peptide in cardiac arrest.

We have investigated in the rat, immunocytochemically, the expression of beta-amyloid peptide in glial cells following ischemia-reperfusion brain injury. The postischemic brain injuries were studied at survival times from 2 days to 12 months. The reactive astrocytes with indirect staining for beta-amyloid peptide were observed in brain till 7 days postischemia. beta-Amyloid positive astrocytes disappeared transiently on the 14 days and then reappeared in the 6 months and again disappeared at 9 months after brain injury. Transient ischemia temporarily induced beta-amyloid peptide expression in reactive astrocytes, but this expression peaked at 7 days and 6 months. A glial appearance of beta-amyloid peptide direct staining occurred at a time when extensive neuronal loss was evident.