A comparison of hydrolyzed L‐ and synthesized DL‐amino acids for complete parenteral nutrition

Abstract

Two comparable groups of patients received high calorie intravenous diets in which theThe importance of adequate parenteral nutrition in serious illnesses complicated by trauma or sepsis is realized to be an important factor in prognosis when nasogastric feeding is impractical, and it has become an inseparable part of intensive careY' 21 Amino acid solutions and fat emulsions have now become available so that total parenteral nutrition can be preserved, and evidence has accumulated that the amino acid solutions contribute significantly to the nitrogen-sparing effects of high calorie intravenous diets. 2 , 4, 5, 14 Amino acid preparations are either derived by hydrolysiS from protein or synthesized from simpler organic structures. The hydrolyzed and synthesized aminoReceived for publication June 6, 1967. acid preparations currently available contain either L-amino acids or DL-amino acid racemates. Because of known differences in metabolic utilization between Land DL-amino acids it was considered advisable to compare the effectiveness of the synthesized DL-amino acid preparation with a similar total amino acid nitrogen intake in the form of a hydrolyzed preparation containing only L-amino acids. The hydrolized preparation had been shown in several earlier studies to be used effectively for protein synthesis. 1 , 4, 5, 7, 18 MaterialsThe solutions used were a hydrolyzed L-amino acid preparation (Aminosol) and a preparation of synthesized DL-amino acids ( Trophysan). The volumes of the 61

Intravenous feeding in infants.

“…Amino acid infusates are prepared either by hydrolysis of natural protein when the amino acids are present in the L-form (aminosol prepared from casein) or by synthesis of the individual amino acids when they may be present as a mixture of the D-and L-forms (Trophysan) or entirely as the L-forms (Vamin and Aminofuscin). L-amino acids are known to be more effective than D-amino acids in maintaining positive nitrogen balance and promoting protein synthesis (Jarnum et al, 1969;Peaston, 1968). Most amino acid solutions contain a non-nitrogenous source of calories such as glucose, fructose, ethanol, or sorbitol, and the manufacturers normally include the caloric value of the amino acids in the total calorie content of the solution.…”