title: [The effect of proteinase inhibitors in rats. 1. Report. Effect of a short-term application on the N balance, the free amino acids in liver and muscles and the biological half-life of the intestinal tissue proteins].
abstract: Short-term trials with a triazin derivative and a peptide aldehyde were carried out to investigate the in-vivo administration of proteinase inhibitors in rats for improving the N balance of the animals. The results of N balances suggest that the peptide aldehyde may be regarded as a promising substance that may be used to increase the rate of utilization of the absorbed N in the intermediary metabolism. The short-term use of both active compounds did not affect the true N digestibility. The two compounds did not influence the concentration of free amino acids in the liver and muscle tissue under the experimental feeding conditions used. Similarly, tests of the biological half-life of proteins taken from the small and large intestine did not reveal any changes due to the presence of the inhibitors. Animals receiving a protein-free diet exhibited longer half-life periods for proteins from the small and large intestine compared with animals of the other groups. A protein-free nutrition of the animals caused a general increase in the levels of free non-essential amino acids in the liver. This was accompanied by a simultaneous decrease in essential amino acids. The same type of nutrition led to a general decline in the concentration of free amino acids in muscular tissue, particularly of the essential amino acids. High-protein nutrition led especially to an increase in the concentration of branched-chain amino acids in both types of tissues investigated.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004064:Digestive System / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006207:Half-Life; D008099:Liver / Q000032:analysis; D009132:Muscles / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D010447:Peptide Hydrolases; D011480:Protease Inhibitors; D011506:Proteins / Q000378:metabolism; D051381:Rats; D014227:Triazines / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D004791:Enzyme Inhibitors; D011480:Protease Inhibitors; D011506:Proteins; D014227:Triazines; D010447:Peptide Hydrolases; D009584:Nitrogen
vernacular_title: Untersuchungen zur Wirkung von Proteinaseinhibitoren bei Ratten