title: Absorption of lactose from colon of newborn piglet.
abstract: Piglets in three age groups (1-3, 9-11, and 16-25 days after birth) were used for in vivo colonic perfusions. Studies compared an isosmolar (312 mosM) with a high osmolar (551 mosM) solution and two equimolar substrates (with hexose concentrations of 73.1 mM), lactose and glucose-galactose. From the isosmolar perfusates, lactose absorption was 0.43 +/- 0.04 in the 18-20 day olds and 1.04 +/- 0.2 mumol.cm-1.min-1 in the 1-3 day olds; absorption from the glucose-galactose solution was negligible in all age groups (less than 0.05 +/- 0.05 mumol.cm-1.min-1). From the high osmolar perfusate, lactose absorption also exceeded that of glucose and galactose. In a third set of perfusion studies, the concentration of lactose was varied between 15 and 240 mM perfusate. Five-day-old animals absorbed 67% more lactose than 18-day-old animals; the right colon absorbed 57% more than the left. Lactose absorption, correlated with its concentration in the perfusate (r = 0.99), was nonsaturable at concentrations up to 240 mM, and was correlated with the uptake both of sodium (r2 = 0.59 for young and 0.64 for older neonates) and of chloride (r2 = 0.55 for young and 0.31 for older neonates). The results suggest that lactose may be removed from the colon without apparent cleavage by beta-galactosidase.
authors.affiliation: Department of Pediatrics, Ohio State University, Children's Hospital, Columbus 43205.
authors.forename: R D
authors.initials: RD
authors.lastname: Murray
authors.forename: A H
authors.initials: AH
authors.lastname: Ailabouni
authors.forename: P A
authors.initials: PA
authors.lastname: Powers
authors.forename: H J
authors.initials: HJ
authors.lastname: McClung
authors.forename: B U
authors.initials: BU
authors.lastname: Li
authors.forename: L A
authors.initials: LA
authors.lastname: Heitlinger
authors.forename: H R
authors.initials: HR
authors.lastname: Sloan
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D050260:Carbohydrate Metabolism; D002712:Chlorides / Q000378:metabolism; D003106:Colon / Q000378:metabolism* / Q000502:physiology; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000201:enzymology / Q000378:metabolism; D007583:Jejunum / Q000201:enzymology; D043322:Lactase; D007785:Lactose / Q000378:metabolism*; D009994:Osmolar Concentration; D010477:Perfusion; D012964:Sodium / Q000378:metabolism; D013552:Swine; D014867:Water / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D002712:Chlorides; D014867:Water; D012964:Sodium; D043322:Lactase; D001616:beta-Galactosidase; D007785:Lactose