Intravenous Utilization of Partial Acid Hydrolysates of Proteins

Abstract

We have determined the minimum amount required to maintain nitrogen balance of a complete acid hydrolysate of casein fortified with tryptophane and cysteine after intravenous injection into female dogs. The same was done for a partial acid hydrolysate of casein similarly fortified. Although 83 to 75% of the amino acids of the partial hydrolysate were bound in peptides, this partial hydrolysate was just as effective in maintaining nitrogen balance as was the complete hydrolysate given at the minimum level (120 mg N/kg/day), which would maintain nitrogen balance. This provides excellent evidence that the peptides of the partial acid hydrolysate are utilized for anabolic processes. Partial and complete casein hydrolysates and partial fibrin hydrolysates were fortified in different ways with tryptophane, cysteine, and methionine and the effectiveness was studied of each fortified hydrolysate in maintaining nitrogen balance after intravenous administration.