title: Activities of gastric, pancreatic, and intestinal brush-border membrane enzymes during postnatal development of dogs.
abstract: OBJECTIVE
  To measure activities of digestive enzymes during postnatal development in dogs.
  
  
  METHODS
  Gastrointestinal tract tissues obtained from 110 Beagles ranging from neonatal to adult dogs.
  
  
  METHODS
  Pepsin and lipase activities were measured in gastric contents, and amylase, lipase, trypsin, and chymotrypsin activities were measured in small intestinal contents and pancreatic tissue. Activities of lactase, sucrase, 4 peptidases, and enteropeptidase were assayed in samples of mucosa obtained from 3 regions of the small intestine.
  
  
  RESULTS
  Gastric pH was low at all ages. Pepsin was not detected until day 21, and activity increased between day 63 and adulthood. Activities of amylase and lipase in contents of the small intestine and pancreatic tissue were lower during suckling than after weaning. Activities of trypsin and chymotrypsin did not vary among ages for luminal contents, whereas activities associated with pancreatic tissue decreased between birth and adulthood for trypsin but increased for chymotrypsin. Lactase and gamma-glutamyltranspeptidase activities were highest at birth, whereas the activities of sucrase and the 4 peptidases increased after birth. Enteropeptidase was detected only in the proximal region of the small intestine at all ages.
  
  
  CONCLUSIONS
  Secretions in the gastrointestinal tract proximal to the duodenum, enzymes in milk, and other digestive mechanisms compensate for low luminal activities of pancreatic enzymes during the perinatal period. Postnatal changes in digestive secretions influence nutrient availability, concentrations of signaling molecules, and activity of antimicrobial compounds that inhibit pathogens. Matching sources of nutrients to digestive abilities will improve the health of dogs during development.
authors.affiliation: Department of Biological Sciences, College of Arts and Science, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Randal K
authors.initials: RK
authors.lastname: Buddington
authors.forename: Jan
authors.initials: J
authors.lastname: Elnif
authors.forename: Christiane
authors.initials: C
authors.lastname: Malo
authors.forename: Jillian B
authors.initials: JB
authors.lastname: Donahoo
mesh_terms: D000375:Aging / Q000502:physiology*; D000681:Amylases / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D000833:Animals, Suckling; D002918:Chymotrypsin / Q000378:metabolism; D004285:Dogs / Q000254:growth & development*; D005766:Gastrointestinal Contents; D007422:Intestines / Q000201:enzymology*; D008049:Lipase / Q000378:metabolism; D008871:Microvilli / Q000201:enzymology*; D010179:Pancreas / Q000201:enzymology*; D010434:Pepsin A / Q000378:metabolism; D013270:Stomach / Q000201:enzymology*; D014357:Trypsin / Q000378:metabolism
chemical_list: D008049:Lipase; D000681:Amylases; D002918:Chymotrypsin; D014357:Trypsin; D010434:Pepsin A