CHANGES IN PROTEIN-KINASE-C ISOZYMES IN THE RAT HIPPOCAMPUS FOLLOWINGTRANSIENT HYPOXIA

The effects of hypoxia on protein kinase C (PKC) isozymes (alpha, beta I, betaII, and gamma) were examined in the hippocampus from rats subje cted to hypoxic conditions (5% 0, in 95% N2) for 30 min in a chamber. Western blot analysis revealed that the total amounts of PKC-alpha (- 26.0% of control) and -gamma (- 32.7% of control) were decreased signi ficantly at the end of hypoxia, which was followed by the reduction of that of PKC-betaII (- 23.7% of control at 7 days after hypoxia). Wher eas, the PKC activities, which were measured by the incorporation of [ gamma-P-32] into a specific PKC substrate peptide, in both the cytosol ic and the particulate fractions did not change. The reductions of PKC -gamma and -alpha at the end of hypoxia may be related to the followin g neuronal degeneration.