α 1-antitrypsin and antichymotrypsin in human milk: Origin, concentrations, and stability

Winyoo Chowanadisai, Bo Lönnerdal

Research output: Contribution to journalArticle

51 Scopus citations

Abstract

Background: The protease inhibitors α 1-antitrypsin and antichymotrypsin are present in human milk, but little is known about their roles in protein digestion during infancy. It has been hypothesized that α 1-antitrypsin and antichymotrypsin may modulate digestion in the infant gut. Objective: We determined whether the mammary gland expresses α 1-antitrypsin and antichymotrypsin, measured α 1-antitrypsin and antichymotrypsin throughout lactation, assessed the resistance of α 1-antitrypsin to proteolysis, and determined the potential of α 1-antitrypsin to affect the survival of other milk proteins. Design: A pool of complementary DNA from the human mammary gland was analyzed with polymerase chain reaction to detect genes for α 1-antitrypsin and antichymotrypsin. α 1-Antitrypsin and antichymotrypsin concentrations were measured in milk samples obtained longitudinally (days 4-47) from 8 women. An in vitro model of infant digestion was used to assess the digestive stability of α 1-antitrypsin against pepsin and pancreatin. Lactoferrin, with α 1-antitrypsin present, was digested by pancreatin, and the digested proteins were separated. Results: α 1-Antitrypsin and antichymotrypsin concentrations were high in early milk and decreased throughout lactation. Polymerase chain reaction products were detected for both genes. After in vitro digestion, much of the α 1-antitrypsin was still intact, whereas many other milk proteins were digested. Much of the lactoferrin was still intact after digestion, but only when α 1-antitrypsin was added. Conclusions: The results suggest that α 1-antitrypsin and antichymotrypsin are produced by the mammary gland and are present in milk in relatively high amounts in early lactation. α 1-Antitrypsin may survive digestion and may affect the survival of other proteins.

Original languageEnglish (US)
Pages (from-to)828-833
Number of pages6
JournalAmerican Journal of Clinical Nutrition
Volume76
Issue number4
StatePublished - Oct 2002

Keywords

  • α -Antitrypsin
  • Antichymotrypsin
  • Breast milk
  • Breast-feeding
  • Human milk
  • Infant digestion
  • Mammary gland
  • Milk proteins
  • Protease inhibitors

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Food Science

Fingerprint Dive into the research topics of 'α <sub>1</sub>-antitrypsin and antichymotrypsin in human milk: Origin, concentrations, and stability'. Together they form a unique fingerprint.

  • Cite this