Effect of a new amino acid solution on nutritional status and nitrogen metabolism in rats with chronic renal failure undergoing hyperalimentation.

: We studied the effects of the new amino acid solution MRX-III on the nutritional status and nitrogen metabolism of rats with chronic renal failure (CRF) in comparison with those of a general amino acid solution (MPR-F). The essential amino acids/non-essential amino acids ratio was 3.21 for MRX-III and 1.09 for MPR-F. Rats with CRF, induced by 7/8 renal ablation, were divided into 6 groups of 8 rats each receiving total parenteral nutrition (TPN) containing MRX-III or MPR-F at a non-protein calorie/nitrogen ratio (Cal/N) of 300, 600 or 900 for 7 d. The rats were infused with test solutions containing the same amounts of non-protein calories. The cumulative nitrogen balance, as a nutritional index, in the MRX-III group was significantly higher than that in the MPR-F group at the Cal/N of 600 or 900, and the plasma albumin level at the Cal/N of 300. The plasma transferrin levels at the Cal/N of 900 in the MRX-III groups were significantly higher than those in the corresponding MPR-F groups. At all Cal/N, the MRX-III groups showed low levels of blood urea nitrogen and urinary excretion of ammonia and urea nitrogen as compared with the MPR-F groups at the same Cal/N. The plasma amino acid concentration profiles in the MRX-III groups after TPN showed greater similarity to that in the Normal group as compared with the profiles in the corresponding MPR-F groups. No aggravation of renal failure was observed in any TPN groups during TPN. These results indicate that, in rats with CRF undergoing hyperalimentation, the effects of MRX-III on the nutritional status and nitrogen metabolism are superior to those of the general amino acid solution, MPR-F. It is suggested that MRX-III could safely provide adequate amounts of nitrogen during hyperalimentation.