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.
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.