ACUTE ELEVATION OF INTRACELLULAR PH TRANSLOCATES PROTEIN-KINASE-C ACTIVITIES IN RAT PINEALOCYTES

The relationship between elevation of intracellular pH and activation of protein kinase C in rat pinealocytes was investigated in rat pineal ocytes. It was found that direct elevation of intracellular pH alone b y ammonium chloride or methylamine translocated protein kinase C activ ities in a dose-dependent manner. This translocation was blocked by EG TA,suggesting a requirement of Ca2+ for the process. However, elevatio n of intracellular pH by methylamine had no significant effect on intr acelluIar Ca2+ or diacylglycerol content, suggesting the translocation was not due to increased intracellular Ca2+ or diacylglycerol content s. These data suggest that elevation of intracellular pH alone can tri gger activation of protein kinase C through a mechanism distinct from increases in diacylglycerol or intracellular Ca2+. (C) 1944 Academic P ress, Inc.