CHRONIC ETHANOL EFFECTS ON GLYCOCONJUGATES AND GLYCOSYLTRANSFERASES OF RAT-BRAIN

We studied the effects of a four week administration of low doses of e thanol on glycoconjugates of the synaptosomal and microsomal fraction prepared from the brain of rats aged 2 and 7 months. Synaptosomes were the more sensitive to ethanol treatment. Total lipid bound sialic aci d and neutral glycolipid and glycoprotein content were significantly r educed only in the synaptosomal fraction, with greater differences in the younger age, while glycoprotein sialic acid was not affected. None of the above differences were statistically significant in the micros omal fraction. Ganglioside pattern was altered only in the 2 month rat s, showing a reduction of GM1 and GD1a in the synaptosomal fraction an d of GD1a in the microsomal fraction. UDP-Gal:asialo-mucin galactosylt ransferase, UDP-Gal:GlcCer galactosyltransferase, and UDP-Gal:GM2 gala ctosyltransferase activities were decreased and could account for the observed modifications in glycoconjugate content and distribution.