EFFICACY OF A SYNTHETIC DIPEPTIDE MIXTURE AS THE SOURCE OF AMINO-ACIDS FOR TOTAL PARENTERAL-NUTRITION IN A SUBHUMAN PRIMATE (BABOON) - PLASMA-CONCENTRATION, METABOLIC-CLEARANCE, AND URINARY-EXCRETION OF A SERIES OF DIPEPTIDES

  • 1 January 1984
    • journal article
    • research article
    • Vol. 86  (6) , 1562-1569
Abstract
To assess the efficacy and safety of oligopeptides as substrates for total parenteral nutrition [TPN], the effects of i.v. infusion of a synthetic dipeptide mixture, as compared with a corresponding amino acid mixture, was investigated on a range of parameters of nutrition, metabolism and organ function in baboons was investigated. In all respects, the 2 periods of TPN, each lasting for 1 wk, were identical except for the difference between the forms of amino acids in the parenteral solutions, being in free form in 1 period and in dipeptide form in the other. The dipeptide mixture was composed of a series of 12 dipeptides each containing glycine in the N-terminal position and either an essential or nonessential amino acid in the carboxyl position. The infusion of the dipeptide mixture and the amino acid mixture had similar effects on parameters of protein nutrition (e.g., N balance, plasma aminogram, urinary excretin of 3-methylhistidine) and metabolism (such as plasma concentrations of insulin, glucose, lipids). During infusion of the dipeptide mixture, rapid metabolic clearance resulted in a barely detectable concentration of most dipeptides in plasma. Total loss of dipeptides was 1.3% .+-. 0.1% of the infused amount. The functions of liver, kidney, bone marrow and the immune system remained the same before and during the 2 periods of treatment. There was efficient utilization of dipeptides when infused as a mixture, and parameters of nutrition, metabolism and organ function were well maintained after 1 wk of TPN with the dipeptide mixture acting as the sole N source.