title: Early weaning reduces small intestinal alkaline phosphatase expression in pigs.
abstract: Expression of the small intestinal alkaline phosphatase (IAP) is enterocyte differentiation dependent and plays essential roles in the detoxification of pathogenic bacterial lipopolysaccharide endotoxin, maintenance of luminal pH, organic phosphate digestion, and fat absorption. This study was conducted to examine the effect of early weaning on adaptive changes in IAP digestive capacity (V(cap)) and IAP gene expression compared with suckling counterparts in pigs at ages 10-22 d. Weaning decreased (P < 0.05) IAP enzyme affinity by 26% and IAP maximal enzyme activity by 22%, primarily in the jejunal region, with the jejunum expressing 84-86% of the whole gut mucosal IAP V(cap) [mol/(kg body weight.d)]. The majority (98%) of the jejunal mucosal IAP maximal activity was associated with the apical membrane and the remaining (2%) existed as the intracellular soluble IAP. Weaning reduced the abundance of the 60-kDa IAP protein associated with the proximal jejunal apical membrane by 64% (P < 0.05). Furthermore, weaning reduced (P < 0.05) the relative abundance of the proximal jejunal IAP mRNA by 58% and this was in association with decreases (P < 0.05) in the abundances of cytoplasmic (27%) and nuclear (29%) origins of IAP caudal-associated homeobox transcription factor 1. In conclusion, early weaning decreased small intestinal IAP V(cap), IAP catalytic affinity, and IAP gene expression, and this may in part contribute to the susceptibility of early-weaned piglets to increased occurrence of enteric diseases and growth-check.
authors.affiliation: Center for Nutrition Modeling, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
authors.forename: Dale
authors.initials: D
authors.lastname: Lackeyram
authors.forename: Chengbo
authors.initials: C
authors.lastname: Yang
authors.forename: Tania
authors.initials: T
authors.lastname: Archbold
authors.forename: Kendall C
authors.initials: KC
authors.lastname: Swanson
authors.forename: Ming Z
authors.initials: MZ
authors.lastname: Fan
mesh_terms: D017677:Age Distribution; D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism*; D000822:Animal Husbandry; D000818:Animals; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D007421:Intestine, Small / Q000201:enzymology*; D008297:Male; D013552:Swine / Q000378:metabolism*; D014886:Weaning
chemical_list: D000469:Alkaline Phosphatase