Chronic ethanol effects on the expression of phospholipase C isozymes and Gq/11-protein in primary cultures of astrocytes.

The goal of this investigation was to determine whether chronic ethanol exposure alters the expression of specific protein sites distal to receptors [Gq/11-protein, phospholipase C (PLC) isozymes] in primary cultures of astrocytes obtained from neonatal rat cortex. The protein expression (immunolabeling) of the PLC-beta 1, -gamma 1, -delta 1 isozymes and of the Gq/11 alpha subunit was determined by Western blot analysis using specific monoclonal antibodies. The PLC-beta 1, -gamma 1, -delta 1 isozymes and the Gq/11 alpha subunit migrated at apparent molecular masses (PLC-beta 1, 41 kDa; PLC-gamma 1, 145 kDa. PLC-delta 1, 85 kDa: Gq/11 alpha protein, 42 kDa). Thus, a PLC-beta 1 fragment of 41 kDa, but not the biologically active 150 kDa PLC-beta 1, was detected in primary cultures of astrocytes. Chronic ethanol exposure (4 days) resulted in a significant increase in the expression of PLC-delta 1, whereas under identical conditions, the expression of PLC-beta 1, -gamma 1, and of the alpha subunit of Gq/11 protein was not significantly altered in astrocytes. These results suggest that chronic ethanol exposure results in an increased expression of the PLC-delta 1, isozyme in primary cultures of astrocytes.