Muscle amino acid flux in patients receiving branched-chain amino acid solutions after surgery.
The metabolism and efficacy of branched-chain amino acids (BCAAs)-enriched parenteral solutions in patients after surgery are unclear. This prospective clinical study compared two groups of patients (n = 13) receiving either a 25% BCAA solution or a 45% BCAA solution at 30 kcal/kg/day and 1.5 gm protein/kg/day for 7 days after operation. Whole-body nitrogen balance and forearm muscle amino acid and ketoacid flux were measured. There were no significant differences between the two groups in mean cumulative nitrogen balance (+13.1 gm versus +18.0 gm) between the two groups. Patients receiving the 45% BCAA solution had significant mean uptake of total BCAA, leucine, and isoleucine compared with results in patients receiving the 25% BCAA solution. Despite this increased uptake of BCAA in the 45% BCAA group, there was no increased efflux of alanine, glutamine, or the BCAA ketoacids, ketoisocaproic, ketoisovaleric, or ketomethylvaleric. However, increased release of aspartate was noted in the 45% BCAA group compared with the 25% BCAA group. Thus use of a 45% BCAA-enriched solution infused in patients after surgery results in a significant increase in forearm muscle uptake of the BCAA that is not demonstrated in whole-body nitrogen economics.
D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000378:metabolism*; D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage*; D002149:Energy Intake; D005950:Glucose Solution, Hypertonic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D011182:Postoperative Care; D001749:Urinary Bladder Neoplasms / Q000601:surgery
D000596:Amino Acids; D000597:Amino Acids, Branched-Chain; D005950:Glucose Solution, Hypertonic; D009584:Nitrogen