Developmental changes of sugar transport in the ovine small intestine.
Intestinal monosaccharide transport was studied in young lambs (age: up to 1 week) and in older lambs (age: 2.5-4 months) with well developed forestomach system employing everted sacs of small intestine. Both glucose and galactose were transported against a high concentration gradient from the mucosal to the serosal side of the intestinal wall in young lambs. In the older lambs glucose was transported only against a small concentration gradient, when intestinal glucose metabolism was diminished by reducing the pH of the incubation medium from 7 to 5. Galactose and alpha-methyl-glucoside, which are not markedly metabolized by the intestine, were transported against a small but similar concentration gradient at both pH values in these animals. In young lambs, however, at pH 5 intestinal galactose transport was lower than at pH 7. These results indicate that active intestinal monosaccharide transport becomes rudimentary in the maturing sheep.
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001693:Biological Transport, Active; D005690:Galactose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007583:Jejunum / Q000254:growth & development / Q000378:metabolism*; D008757:Methylglucosides / Q000378:metabolism; D009005:Monosaccharides / Q000378:metabolism*; D012756:Sheep / Q000378:metabolism*
D008757:Methylglucosides; D009005:Monosaccharides; D005947:Glucose; D005690:Galactose