title: Changes in the functions of the intestinal brush border membrane during the development of the ruminant habit in lambs.
abstract: 1. Brush border membrane vesicles were prepared from lamb enterocytes. These were used to study the changes in the enzyme contents and the transport capacities which occur during the change from a milk to a roughage diet. 2. Na+-dependent transport of D-glucose was present in all regions of the small intestine of pre-ruminant lambs and absent in ruminants. 3. Na+-dependent transport of L-proline was present in all regions of the small intestine irrespective of the age of the animal. 4. Phosphate transport was seen only in the presence of a transmembrane pH gradient (acid outside). The transport was not stimulated by either Na+ or K+. The transport capacity increases 2-fold as the animal becomes ruminant. 5. The activities of lactase and maltase diminished with age. Alkaline phosphatase and aminopeptidase N activities remain constant. Sucrase activity cannot be detected in lambs of any age.
authors.affiliation: Department of Biochemistry, University College of Wales, Aberystwyth, Dyfed, UK.
authors.forename: S P
authors.initials: SP
authors.lastname: Shirazi-Beechey
authors.forename: R B
authors.initials: RB
authors.lastname: Kemp
authors.forename: J
authors.initials: J
authors.lastname: Dyer
authors.forename: R B
authors.initials: RB
authors.lastname: Beechey
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000833:Animals, Suckling; D001693:Biological Transport, Active; D004032:Diet; D005260:Female; D005947:Glucose / Q000493:pharmacokinetics; D007421:Intestine, Small / Q000254:growth & development / Q000378:metabolism*; D008297:Male; D008871:Microvilli / Q000378:metabolism; D010710:Phosphates / Q000493:pharmacokinetics; D011392:Proline / Q000493:pharmacokinetics; D012756:Sheep / Q000254:growth & development / Q000378:metabolism*; D000520:alpha-Glucosidases / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D010710:Phosphates; D011392:Proline; D000469:Alkaline Phosphatase; D000520:alpha-Glucosidases; D001616:beta-Galactosidase; D005947:Glucose