Dietary regulation of intestinal glycosyl-transferase activities: relation between developmental changes and weaning in rats.
Activities of rat intestinal fucosyl-transferase (GDP-fucose: glycoprotein fucosyl-transferase; EC 2.4.1.68) and sialyl-transferase (N-acetylneuraminyl-transferase; EC 2.4.99.1) respectively exhibited a significant increase following weaning and a steady decrease between birth and weaning. The variations of the two glycosyl-transferase activities with age could not be explained by the presence of inhibitory factors in microsomes or cytosol, nor were they due to a natural modification of the milk composition at the end of lactation. The increase in fucosyl-transferase activity that followed weaning was prematurely induced by early weaning. Prolonged nursing prevented the normal increase in fucosyl-transferase activity, and late weaning delayed the increase. The sensitivity to the modification of the time of weaning indicated a major effect of dietary changes, related to the introduction of a solid carbohydrate-rich diet, on the developmental pattern of this enzyme. However, a stress response could not be excluded after early weaning since the corticosterone level of the early weaned rats was enhanced as compared to that of suckling rats. For sialyl-transferase, early weaning caused a slightly greater than normal decrease in the activity, whereas prolonged nursing only weakly diminished the normal decrease in the activity. Moreover, late weaning had no effect on the sialyl-transferase activity. The age-related variations of this enzyme likely are due to factors independent of diet. Thus, the developmental variations of the fucosyl- and sialyl-transferases appear to be differently regulated.
Biol
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MC
Department of General and Medical Biochemistry, INSERM U 189-CNRS, Lyon-Sud Medical School, Oullins, France.
Pintori
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Mathian
B
B
Louisot
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D000375:Aging / Q000378:metabolism; D000818:Animals; D003345:Corticosterone / Q000097:blood; D004032:Diet; D005647:Fucosyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007422:Intestines / Q000201:enzymology / Q000254:growth & development* / Q000648:ultrastructure; D007774:Lactation / Q000378:metabolism; D008297:Male; D008861:Microsomes / Q000201:enzymology; D008892:Milk; D051381:Rats; D011919:Rats, Inbred Strains; D012799:Sialyltransferases / Q000378:metabolism*; D013997:Time Factors; D014886:Weaning; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D005647:Fucosyltransferases; C020559:Glycoprotein 6-alpha-L-fucosyltransferase; D012799:Sialyltransferases; D003345:Corticosterone; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase