Effects of Simultaneous or Prior Infusion of Sugars on the Fate of Infused Protein Hydrolysates 12

Abstract

Glucose usually is included in amino acid solutions for intravenous infusion. This has seemed desirable because the amino acids can spare body protein only when sufficient calories are provided. Although the calories so gained (usually 200 for a liter of hydrolysate) are far from enough for this purpose, they do add to the total and besides they might serve particularly efficiently being presented at the same time as the amino acids.On the other hand Elman and his co-workers (1) have reported improved retention of the nitrogen of a partial hydrolysate when fructose replaced the usual glucose. In explanation these writers suggest that the cellular uptake of the glucose is relatively too late to spare the amino acids optimally, whereas the fructose is metabolized more quickly.The present study was undertaken to compare the effects of glucose and fructose on the fate of the amino acids and peptides of infused hydrolysates. We have found that the presence of either sugar in certain commercial protein hydrolysates interferes with the tissue utilization of the peptides present; the effect increases in the order 10 per cent fructose, 5 per cent glucose, 10 per cent glucose. It is completely avoided if the sugars are added to the hydrolysate sterilely just before infusion or if the sugars are infused in advance of the hydrolysate. Therefore, we conclude that substances which interfere with peptide utilization are formed during autoclaving by interaction between the sugars and constituents of the hydrolysate.

A method of determining daily nitrogen requirements

“…Xg urea x 0-62 should be substituted for . These latter observations would appear to be in agreement with those earlier workers (Christensen et aL., 1954;Christensen et al, 1955;Brocard, Akoun and Fabiani, 1964;Peaston, 1966;Heller, 1972) who …”

Amino acid and peptide absorption from partial digests of proteins in isolated rat small intestine.

“…nutrition media is well known in man (e.g. Lidstr6m & Wretlind, 1952; Christensen, Wilber, Coyne & Fisher, 1955).…”

Maintenance of metabolism during intensive patient care

“…In many of these studies concomitant infusions of fat emulsion were given (for references see previous section on fat emulsions). The reduction in catabolism has been confirmed by several studies (Christensen et al, 1955;Peaston, 1966b). Infusions of amino-acids do not cause a significant increase in the excretion of amino nitrogen (Brocard, Akoun & Fabiani, 1964;Peaston, 1966b).…”

“…It is therefore rational to give amino-acids and sugar solutions together. This does not increase the total nitrogen excretion but reduces plasma levels of amino-acids and peptides (Christensen et al, 1955), a finding which suggests an improved tissue utilization of the infused amino-acids. The importance of supplying potassium in such sugar and amino-acid solutions has been emphasized by Frost & Smith (1953) who found the optimum potassium load to be 5 mEq/g of infused aminoacid nitrogen.…”

“…The urinary nitrogen output is greater with protein hydrolysates than with plasma infusions (Levine et al, 1957) but this does not mean that plasma is a better source of nitrogen. The suggestion (Christensen et al, 1955) that the Gastric carcinoma, malnutrition simultaneous administration of carbohydrate increases peptide and amino-acid wastage is not supported by an increased urinary nitrogen excretion. The concomitant supply of potassium increases the utilization of nitrogen given intravenously (Frost & Smith, 1953) and again shows that amino-acids are used for tissue repair.…”