Influence of Carbohydrate, Nitrogen Source and Prior State of Nutrition on Nitrogen Balance and Liver Composition in the Adult Rat

Abstract

Animals fed 0.1% of the essential amino acids with sucrose as the carbohydrate had more negative nitrogen balances and a greater accumulation of fat in the liver than animals fed the same quantities of amino acids with corn dextrin. When the amounts of the essential amino acids were doubled (0.2%), differences in nitrogen balances were eliminated for both undepleted and protein-depleted animals fed the two carbohydrates. Glutamic acid fed at a level of 1.65% significantly improved the nitrogen balances of animals fed sucrose, but was without effect on corn dextrin-fed rats; 6.45% of glutamic acid caused a significant improvement in the nitrogen balances of protein-depleted animals fed sucrose but had no effect on the nitrogen balances of animals fed corresponding corn dextrin diets. The livers of animals fed sucrose, except for the proteinfree diet, contained more protein than those of animals fed corresponding diets with corn dextrin; the differences in protein content were statistically significant when the nitrogen balances differed between the groups. It is suggested that corn dextrin in the diet in some fashion facilitates the use of liver protein, or amino acids that would become liver protein, and results in reducing nitrogen output and perhaps in retarding the accumulation of liver fat.