title: Raw soy and purified proteinase inhibitors induce the appearance of inhibitor-resistant trypsin and chymotrypsin activities in Wistar rat duodenal juice.
abstract: Rats were fed raw soybeans or purified soybean proteinase inhibitors by tube to see whether they were able to produce inhibitor-resistant trypsin, as previously demonstrated in humans. Their duodenal chyme contained only 20-50% of the enzymatic activities of animals fed bovine serum albumin (BSA) as test protein. However, both tryptic and chymotryptic activities had considerable resistance to low- and high-molecular-weight inhibitors of serine proteinases. In particular, the tryptic activity demonstrated a high degree of inhibitor resistance. Human alpha 1-antitrypsin and lima bean inhibitor in amounts that inhibited bovine serum albumin-induced trypsin completely caused only 2-12% inhibition of the raw soybean-induced tryptic activity. The inhibitor-resistant tryptic and chymotryptic activities after raw soybean instillation might be caused by the Bowman-Birk and Kunitz trypsin inhibitors. The physiologic significance of an inhibitor-resistant trypsin might be to assure activation of other pancreatic proenzymes. The results of the present rat experiments confirm the previous findings of inhibitor-resistant trypsin in humans.
authors.affiliation: Institute for Nutrition Research, University of Oslo, Norway.
authors.forename: H
authors.initials: H
authors.lastname: Holm
authors.forename: A
authors.initials: A
authors.lastname: Jørgensen
authors.forename: L E
authors.initials: LE
authors.lastname: Hanssen
mesh_terms: D000818:Animals; D002918:Chymotrypsin / Q000096:biosynthesis / Q000187:drug effects*; D004386:Duodenum / Q000201:enzymology; D007419:Intestinal Secretions / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D011480:Protease Inhibitors / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013025:Glycine max; D014357:Trypsin / Q000096:biosynthesis / Q000187:drug effects*; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000494:pharmacology; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000494:pharmacology; D000515:alpha 1-Antitrypsin / Q000494:pharmacology
chemical_list: D011480:Protease Inhibitors; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D000515:alpha 1-Antitrypsin; D014360:Trypsin Inhibitor, Kunitz Soybean; D002918:Chymotrypsin; D014357:Trypsin