DIFFERENTIAL CHANGES IN CELL MORPHOLOGY, MACROMOLECULAR-COMPOSITION AND MEMBRANE-PROTEIN PROFILES OF NEURONS AND ASTROCYTES IN CHRONIC ETHANOL-TREATED RATS

Cellular morphology, macromolecular composition, (DNA, RNA and Protein content) marker enzyme activities for neurons [neuron specific enolas e (NSE)] and astrocytes [glutamine synthetase (GS)] and plasma membran e protein profiles in the bulk isolated neurons and astrocytes from co ntrol and ethanol treated rats were studied. One month aged Wistar rat s were given ethanol as sole drinking fluid for 10 weeks. Scanning ele ctron microscopy revealed a characteristic cell surface smoothening in astrocytes due to ethanol treatment. DNA levels were unaltered, while RNA and Protein contents were decreased in astrocytes and neurons. Fu rther, H-3-leucine incorporation into proteins was decreased in neuron s and astrocytes derived from ethanol treated rats indicating reduced protein synthesis in neurons and astrocytes. GS activity was affected severely suggesting impairment in astrocytic functions. Plasma membran e protein composition was analyzed by 2-D electrophoresis. The analysi s indicated several protein defects in the plasma membranes of neurons and astrocytes, which might be involved in 'membrane disorder' during ethanol challenge. I-125-Wheat Germ agglutinin binding studies showed three prominent proteins (160, 116 and 97 kDa) in astrocyte membrane fraction suggesting the possible involvement of N-terminal glycoprotei ns in altered astrocyte morphology during ethanol ingestion. Impairmen t in the astrocyte cell functions, protein changes in plasma membrane and cellular morphology studies suggest that astrocytes may be more vu lnerable than neurons for ethanol effects.