Isotonic Amino Acid Solution Research Articles

Effects of various arterial infusion solutions on red blood cells in the newborn

AIMTo examine in vitro the effects of brief contact with various infusion solutions on red blood cells from newborn infants, as occurs in the “waste” syringe during routine blood sampling...

Branched-chain amino acid administration in surgical patients. Effects on amino acid and fuel substrate profiles.

During the first five days following gastric bypass surgery, 15 patients received near isotonic amino acid solutions that varied in their branched-chain amino acid (BCAA) content and amino acid profiles (15.6%, 50%, or 100% BCAA solutions). Plasma valine concentrations were elevated in patients receiving 50% and 100% BCAA solutions. Plasma alanine concentrations were highest in patients receiving 50% BCAA. Plasma free fatty acids and blood lactate concentrations were unchanged by either the operation or BCAA administration. Serum glucose concentration was unaffected by the different amino acid administrations and followed the pattern induced by stress initially and later by starvation. beta-Hydroxybutyrate concentrations increased as starvation proceeded and were highest in patients receiving the 15.6% BCAA solution. Branched-chain amino acid-enriched solutions without additional energy may be administered safely to patients recovering from operative trauma. Plasma amino acid concentrations and fuel substrate profiles appear to follow metabolic patterns determined by the physiologic response to stress and starvation and can be affected by large quantities of BCAAs.

The metabolic effects of isotonic amino acid infusion in surgical sepsis

28 normally nourished adult male and female patients who had undergone major elective surgery were maintained on dextrose-free isotonic amino acid solutions as their sole nutritional support. In the 6 days after surgery, 15 patients had no septic complications, 9 developed superficial sepsis, and 4 developed a deep seated collection of pus or deep sepsis. Patients without infection developed and maintained a fasting metabolic fuel profile within the first 3 days and increasingly spared protein. Superficial sepsis caused a small depression in serum ketone body concentrations but did not otherwise alter the fasting profile. Moreover nitrogen balances and plasma albumin and transferrin concentrations were unaltered by superficial sepsis which is not the response usually recognised with infection. Metabolic adaptation to the fasting state was lost in patients with deep sepsis and nitrogen losses were increased with greater decreases in plasma albumin and transferrin.

Peripheral intravenous feeding with isotonic amino acid solutions

Nitrogen balance was studied in ten patients receiving peripheral solutions of the following: (1) 5 per cent dextrose and water; (2) dextrose and 3 per cent amino acids; (3) amino acids alone. Significant improvement in nitrogen balance was observed when amino acids were administered without glucose. This was associated with lower insulin and glucose levels and with elevated levels of free fatty acids and ketones. A new concept on which to base parenteral protein-sparing therapy is presented.

The Significance of Amino-Acids for the Growth in vitro of Human Fibroblasts: I. The Growth Inhibiting Action of Glycine

Introduction Several articles have been published on the growth of tissue cultures in the presence of amino-acids. Although reference to this subject was made as early as 1911, it was not until 1917 that the first comprehensive article appeared. M. R. Lewis and W. H. Lewis (14) obtained a good growth from chick embryo tissues in media containing various combinations of amino-acids and polypeptides of known composition. The cultures, however, were by no means equal to those in plasma or lymph either in extent or duration (15). The names of the amino-acids and polypeptides are not mentioned in the articles nor are their concentrations given. Burrows and Neymann (7) studied extensively the growth of embryonic chicken tissues in the presence of amino-acids. The cultures were grown in a mixture of equal parts of chick plasma and an isotonic amino-acid solution. In order to obtain such a solution of glycocoll, one of the ten amino-acids studied, it was necessary to dilute one part of a 35 per cent solution of glycine with nineteen parts of water. From these figures it appears that the final concentration of the amino-acid in the culture medium was 875 mg. per 100 c.c. Some of the cultures were grown in media only one-fourth of which consisted of an isotonic amino-acid solution. The amino-acids were found to be toxic even in low concentrations. A mixture of a-amino-acids, prepared from egg yolk, also was harmful to growth. However, compounds of higher molecular weight, namely, the peptones of egg yolk and proteins, were found to be non-toxic.