Document Detail

Development and adaptation of protein digestion.
MedLine Citation:
PMID:  3889240     Owner:  NLM     Status:  MEDLINE    
Protein digestion is a complex process in which most aspects have a developmental pattern of activity. Gastric pH and intestinal peptide and amino acid transport as well as the activities of pepsinogen, trypsin, chymotrypsin, enterokinase and intestinal dipeptidases vary during development. No one species has been assessed for all these aspects and it is not possible to present an integrated developmental view of protein digestion. The following developmental changes, however, have been observed. Gastric pH declines, and peptic and pancreatic proteases exhibit increasing activity in pigs and rats after birth. The increase in pigs is gradual over several weeks starting at birth, whereas the increases in the rat begin at 2 wk, just prior to the time of weaning. The activities of dipeptidases in the rat and pig, peptide transport systems in the guinea pig and rabbit and amino acid transport systems in the rat, rabbit, guinea pig and chicken, however, appear (with few exceptions) to be active in the small intestine at the time of birth. Frequently, these activities peak in the neonate and decline during the postnatal period. In the rat, dietary protein tends to increase the activities of pancreatic proteases and intestinal peptidases and to increase the rate of uptake of amino acids by the intestinal epithelium. Individual dietary amino acids also influence amino acid transport systems. The data indicate that most processes in protein digestion undergo marked changes during prenatal and postnatal development and are influenced by the level of feeding and composition of the diet.
R E Austic
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of nutrition     Volume:  115     ISSN:  0022-3166     ISO Abbreviation:  J. Nutr.     Publication Date:  1985 May 
Date Detail:
Created Date:  1985-06-26     Completed Date:  1985-06-26     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  0404243     Medline TA:  J Nutr     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  686-97     Citation Subset:  IM    
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MeSH Terms
Amino Acids / metabolism
Child, Preschool
Dietary Proteins / metabolism*
Embryonic and Fetal Development
Endopeptidases / metabolism
Enteropeptidase / metabolism
Guinea Pigs
Hydrogen-Ion Concentration
Intestines / enzymology,  metabolism,  physiology*
Pancreas / enzymology
Species Specificity
Stomach / enzymology,  metabolism,  physiology*
Reg. No./Substance:
0/Amino Acids; 0/Dietary Proteins; EC 3.4.-/Endopeptidases; EC

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