BIFEMELANE INDUCES TRANSLOCATION OF PROTEIN KINASE-C IN THE CA3, BUT NOT THE CA1, REGION OF GUINEA-PIG HIPPOCAMPUS

We made use of the [3H]phorbol 12,13-dibutyrate binding assay to investigate the effects of bifemelane on the subcellular distribution of protein kinase C in the CA3 and CA1 regions of guinea-pig hippocampal slices. Bifemelane, a drug that augments the long-term potentiation in the CA3 region, significantly induced the translocation of [3H]phorbol 12,13-dibutyrate binding activity from the cytosol to the membrane in a dose-dependent manner (10-8 to 10-6 M) and with no effects on total binding activity in the CA3 region. Bifemelane, at a concentration of 10-6 M, was without effect on the subcellular distribution of [3H]phorbol 12,13-dibutyrate binding activity in the CA1 region. These observations suggest that bifemelane acts directly on the hippocampus to induce translocation of protein kinase C in the CA3 region. Such an effect may be associated with the bifemelane-induced augmentation of the long-term potentiation in this region of the brain.