Biosynthesis of Glycoproteins in the Intestinal Mucosa

Abstract

To determine the effect of diets on the biosynthesis of glycoproteins in the intestinal mucosa, male Sprague-Dawley rats were fed, ad libitum, high-carbohydrate, high-fat and high-protein diets. In in vivo methodology, the animals from each dietary group received an intraperitoneal injection of [¹⁴C]-fucose, or [¹⁴C]-galactose or [¹⁴C]-glucosamine. Incorporated radioactivity was detected in the different subcellular fractions. In in vitro methodology, five glycosyl-transferases were studied on microsomes and cell sap. In vivo, only the high-fat diet induces a decrease in the incorporation of [¹⁴C]-glucosamine in the macromolecules. In vitro, only the fucosyl-transferase activity is modified by several diets: as compared with an increase in the activity of the control with the age of the animals, high-protein diet induces a slight activation after 2 weeks of diet, while high-carbohydrate and particularly high-fat diets inhibit the enzyme activity. The inhibition is the same when high-fat diet consists of either oil mixture or triolein or oleic acid or linoleic acid and becomes significant with a supplementation rate of 10%.

Effect of Chronic Ethanol Administration on Intestinal Microvillus Membrane Glycosylation in Rats Fed Rat Pellet Diet and Protein-Rich Diet.

“…It is reported that both quantity and quality of dietary components induce modifications in membrane glycosylation in the intestine [5]. Membrane fucosylation and sialylation processes are influenced by variations in the carbohydrate, lipid and protein contents of the diet in weanling [6] and adult animals [7]. Thus, any change in the membrane oligosaccharides in the intestine could influence the functional characteristics of the tissue.…”

“…Biol et al [6] reported enhanced fucosyltransferase activity in rat intestinal mucosa in response to the feeding of a high-protein diet. The reported increase in fucosyltransferase activity in response to HP intake may be due to modification of enzyme biosynthesis [26] .…”

“…Protein was determined by the method of Lowry et al [14] with bovine serum albumin used as the standard. Membrane sialic acid, fucose, hexose, and hexosamine contents were determined as described [6,12].…”

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

“…The discovery of the dolichol pathway of the glycoprotein mannosylation gave rise to sev eral works dealing with the adaptation of this compound to various diets, either in the liver [18,19], the adipose tissue [13] or the pan creas [3. 4], In a previous paper [5], we described large variations of intestinal glycosyltransferase activities, which do not in volve dolichol intermediates, to nutritional factors: activation of fucosyltransferase ac tivity by a high-protein diet and inhibition by a high-fat diet. In this last case, an additional direct regulatory effect of the free fatty acids provided by the diet was demonstrated [2], In these studies, however, supplemented diets were used so that nutritional interpretation was not obvious in view of the high varia tions in the energy/protein ratios of the diets, inducing very different nutrient intakes.…”

Prebiotic Properties of Galursan HF 7K on Mouse Gut Microbiota

“…Dietary supplements have gained attention in recent years. Soluble dietary oligosaccharides extracted from various sources have been shown to promote the proliferation of specific beneficial bacterial groups and thus are termed prebiotics [18,19,20,21,22,23]. Examples of prebiotics include fructooligosaccharides, galactooligosaccharides, arabinose, galactose, inulin, raffinose, mannose, lactulose, stachyose, mannanoligosaccharides, xylooligosaccharides, palatinose, lactosucrose, glycooligosaccharides, isomaltooligosaccharides, and soybean oligosaccharides [20,24,25,26].…”