CHANGES IN PROTEIN-KINASE-C ISOZYMES IN THE RAT HIPPOCAMPUS FOLLOWING TRANSIENT HYPOXIA

The effects of hypoxia on protein kinase C (PKC) isozymes (alpha, betaI, betaII, and gamma) were examined in the hippocampus from rats subjected 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 significantly 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). Whereas, the PKC activities, which were measured by the incorporation of [gamma-P-32] into a specific PKC substrate peptide, in both the cytosolic and the particulate fractions did not change. The reductions of PKC-gamma and -alpha at the end of hypoxia may be related to the following neuronal degeneration.