CHRONIC ETHANOL EFFECTS ON THE EXPRESSION OF PHOSPHOLIPASE-C ISOZYMESAND G(Q 11)-PROTEIN IN PRIMARY CULTURES OF ASTROCYTES/

The goal of this investigation was to determine whether chronic ethano l exposure alters the expression of specific protein sites distal to r eceptors [G(q/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) i sozymes and of the G(q/11) alpha subunit was determined by Western blo t analysis using specific monoclonal antibodies. The PLC-beta(1), -gam ma(1), -delta(1) isozymes and the G(q/11) alpha subunit migrated at ap parent molecular masses (PLC-beta(1), 41 kDa; PLC-gamma(1), 145 kDa; P LC-delta(1), 85 kDa; G(q/11) alpha protein, 42 kDa). Thus, a PLC-beta( 1) fragment of 41 kDa, but not the biologically active 150 kDa PLC-bet a(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 o f PLC-beta(1), -gamma(1), and of the a subunit of G(q/11)-protein was not significantly altered in astrocytes. These results suggest that ch ronic ethanol exposure results in an increased expression of the PLC-d elta(1) isozyme in primary cultures of astrocytes.