[Mechanism of lipid inhibitory effect on intestinal fucosyl-transferase in the rat].

High-fat diets decrease microsomic and soluble fucosyl-transferase activities in rat intestinal mucosa. This inhibition is not due to qualitative (pHi) or quantitative (relative activities) changes ion three isoenzymes, nor is it caused by alterations in the kinetic behaviour of these enzymes (Km, V). It is also not due to a direct effect of the fatty acids on the enzyme activities. It seems reasonable to suggest that a decreased biosynthesis of the fucosyl-transferase occurs as a result of the high-fat diets.