Characterization of microsomal glycosyl-transferases of rat pancreas and influence of diets

Four rat pancreatic microsomal glycosyl-transferases (fucosyl-, galactosyl-, mannosyl- and N-acetylglucosaminyl-transferases) are studied and characterized for their optimal conditions and their relation with interfering reaction (glycosyl-nucleotide pyrophosphatases, osidases and proteinases). Dietary treatments of the rats induce modification: for all the transferase activities, the highest levels are found in a high-starch diet and the lowest one in a high-fat diet. The activities found in the standard diet are at the level of the high-starch or of the high-fat diet depending on the enzyme studied. The observed modifications are not explained by alterations in physico-chemical parameters of the enzymes or by intervention of glycosyl-nucleotide pyrophosphatases, osidases or proteolytic enzymes. The modifications observed for the mannosyl-transferase are predominantly found in a lipid fraction extracted by chloroform-methanol ($\text{2}\text{1}$).