[Metabolic effect of a carbohydrate combination during simultaneous amino acid infusion]

During a period of 12 hours, eight normal subjects were infused with an electrolyte containing combined 24% carbohydrate solution of fructose, glucose, and xylitol at a ratio of 2:1:1 (Triofusin E 1000 Pfrimmer) with a rate of supply of 0.6 gm/kg/h. Lamino acids (Aminofusin L 10% carbohydrate-free Pfrimmer) were simultaneously administered at a rate of 0.1 gm/kg/h. The serum substrate concentrations of fructose, glucose and xylitol and their excretion were measured. The utilization of fructose was 99%, of glucose practically 100% and of xylitol 88%. In accordance with the slight glucose increase, the concentration of insulin also showed an only slight increase. An increased serum concentration of oxalate was not observed. Despite the infusion of a glycine containing amino acid mixture, the excretion of oxalic acid even decreased during the infusion. The dilution effect measured by means of hematocrit, hemoglobin, erythrocyte count, total protein, and albumin was between 2 and 5%. The lactate concentration did not change significantly whereas hydroxy butyrate decreased significantly by the end of the infusion indicating the antiketogenic effect. A disturbance of fat metabolism was not observed as was indicated by the concentrations of neutral fat and cholesterol. The decrease of free glycerol cannot be clearly explained. A highly significant reduction of the serum uric acid concentration resulted from an increased renal elimination. The electrolyte concentrations of potassium, sodium, calcium and phosphate showed only slight modifications. The concentration of potassium initially rose significantly within normal ranges. Sodium and chloride remained constant whereas calcium decreased slightly but not significantly and phosphate decreased significantly until the 12th hour. The serum transaminase and bilirubin concentrations did not show any change. During the permanent infusion, a respiratory alkalosis developed. The average urinary excretion was 134 ml per hour, the excretion of potassium was 6 mEq/h, of sodium 15 mEq/h, and of phosphate 27 mg/h. The utilazation of a combined carbohydrate solution was in the same range with or without the simultaneous application of amino acids. The reduction of the uric acid concentration and the absent increase of lactate, bilirubin and oxalate may be considered as an additional desirable effect of the simultaneous application of amino acids.