Highlights Cell Metabolic Responses to Amino Acid Infusions in Chronic Uremia

Abstract

There are contradictory reports about whether amino acid supplementation (oral or parenteral) will improve nitrogen balance and carbohydrate utilization, and presumably protein synthesis and energy metabolism, in chronic uremics on maintenance dialysis. The circulating leukocyte is a useful cell model to study the metabolic effects directly. Following 3 control studies at one week intervals, 11 adult chronic uremics on thrice weekly hemodialysis (HD), got 500 ml 10% amino acid infusion (AAI) at the end of each subsequent dialysis for a 3 month period. Blood was obtained pre and post dialysis at intervals and leukocytes isolated. Compared to control periods, after only 12 AAI (1 mo) levels of cell ATP, amino acids GLY, TYR, PHE, and TRP, and protein synthesis (³H-leu incorporation) were improved significantly (p < .05), Cell levels of F1–6P, 3PGA, and 2PGA, but not PYR or lactate, were higher (p<0.05), indicating altered glucose utilization (incubation c 5mM glucose). Multiple regression analysis indicated the improved protein synthesis was associated with simultaneous change in levels of cell ASP, CIT, and PHE and plasma THR, VAL, LEU, TYR, and HIS. Thus AAI in uremics on HD improve cell amino acid balance, protein synthesis and energy levels.