Glycosyltransferase Activities in the Rat Intestinal Mucosa: Comparison between Standard Commercial and Semi-Synthetic Diets

Abstract

Two groups of rats were fed either a commercial (C group) or a semi-synthetic (S group) diet of very similar quantitative composition, which induce similar growth in the animals. Glycosyltransferase activities are very different in the two groups: fucosyltransferase is lower in S group than in C group, regardless of the expression of the results (specific activity versus protein or DNA). The other activities (galactosyl-, N-acetylglucosaminyl-, N-acetylgalactosaminyltransferases) are modified when expressed versus DNA content; N-acetylneuraminyltransferase specific activity is not altered. Since the weight of mucosa is significantly lower in the S group than in the C group, all the total activities are decreased in the S group. The fucosylation process is further characterized by partial purification of the enzyme and study of the synthesis of GDP-fucose. In each case, interfering reactions (glycosyl-nucleotide pyrophosphatases and proteinases) are controlled. The results give evidence that glycosyltransferases are very sensitive to the qualitative composition of the diet.

Intestinal Absorption of Macromolecules and Epithelial Cell Surface Glycosylation in Suckling Rats Nursed on Mothers Fed Low-Protein Diet-I

“…This sug gests the sensitivity of the intestinal fucosylation process to variations in the animal diet. Our results on the chemical analysis of sialic acid and fucose-and lectin-binding characteristics of brush borders in suckling animals from the LP group are in agreement to the observations in adult animals [7], Al though, at present, no information is avail able on glycosyl-transferase activities of in testinal tissue in weanling rats subjected to nutritional stress, it is likely that the ob served changes in the fucosylation pattern of microvillus surface may be related to altera tions in fucosyl-transferase levels under these conditions. However, changes in the availability of substrates, fucosyl-substitution-reactive sites and various cofactors in volved in the fucosylation may also be impli cated in the observed aberrations of epithe lial cell surface glycosylation in response to maternal nutrition.…”

“…The membrane fucose levels and the binding of a-L-fucose-specific lectin, UEAi, were considerably more in pups from LP-diet-fed lactating rats. Interestingly, Biol et al [7] have shown that feeding a semisyn thetic diet to adult rats affects the fucosyltransferase levels without altering the sialyl-transferase activity in intestine. This sug gests the sensitivity of the intestinal fucosylation process to variations in the animal diet.…”

“…The microvillus membrane (MVM) lining the enterocytes contains con siderable amounts of carbohydrates [4], We have previously shown that surface-reactive carbohydrates, in particular sialic acid and fucose, undergo striking modifications dur ing postnatal development in rat intestine [5,6]. During early suckling period, the membrane is rich in sialic acid and contains low levels of fucose but the pattern is re versed on weaning [6], Biol et al [7,8] have described that the quality as well as the quantity of diet affects the glycosyl-transferase levels in intestine. Since milk is the sole source of nutrition for the developing pups during the suckling period and the composi tion of milk is altered in response to changes in the maternal nutrition [9,10], we studied the effect of feeding low-protein (LP) diet (8% protein) to lactating rats on the absorp tion of 125I-labelled proteins and the glycosy lation of intestinal microvillus membrane in suckling rats.…”

Effect of Malnutrition and Hormone Treatments on Intestinal Microvillus Membrane Glycosylation in Suckling Rats

“…Biol el al. [20] have reported stimulation of fucosyltransferase activity in intestine of adult rats fed semisynthetic diets.…”