CHRONIC ETHANOL DOWN-REGULATES GAL-BETA-1,4GLCNAC ALPHA-2,6-SIALYLTRANSFERASE AND GAL-BETA-1,3GLCNAC ALPHA-2,3-SIALYLTRANSFERASE MESSENGER-RNAS IN RAT-LIVER

We have previously demonstrated that chronic ethanol specifically decr eases the hepatic level and rate of synthesis of 2,6-sialyltransferase (2,6-ST). To understand its mechanism of action, effects of 8 weeks o f chronic ethanol feeding on the expression of sialyltransferase (ST) genes in rat liver and kidneys were determined by Northern-blot analys is of ST mRNAs, It was found that, compared with the pair-fed control rats, the percentage decreases in ST mRNAs in the ethanol-fed group we re as follows: liver-Gal-beta-1,4GlcNAc alpha 2,6-ST (2,6-ST): 59% (p < 0.001); liver-Gal-beta-1,3GlcNAc alpha 2,3-ST (2,3-ST): 32% (p < 0.0 1); and kidneys-2,6-ST: 5% (NS), In contrast, glyceraldehyde-3-phospha te dehydrogenase mRNA in both liver and kidneys was unaffected by the same ethanol treatment. Taken together, these results demonstrate that chronic ethanol downregulates the expression of 2,6-ST and 2,3-ST gen es in rat liver.