Effect of Oral Branched-Chain Amino Acids and Glutamine Supplementation on Skeletal Muscle Atrophy After Total Gastrectomy in Rat Model

Background: Sarcopenia is closely related to short-term outcomes of surgery and long-term prognosis. After gastrectomy, a decrease in muscle strength occurs because of insufficient nutrient intake and disturbed digestive function. Branched-chain amino acids (BCAAs) and glutamine (Gln) play vital roles in the signaling pathways regulating protein synthesis and protein degradation. In this study, we investigated the effects of BCAA and Gln supplementation alone or in combination on skeletal muscle atrophy after total gastrectomy in a rat model. Methods: Male Wistar rats were divided into five groups: (1) sham operation (n = 8); (2) total gastrectomized rats (TG [control group], n = 16); (3) TG with BCAA (TG-B, n = 16); (4) TG with Gln (TG-G, n = 16); and (5) TG with BCAA and Gln (TG-BG, n = 16). In all groups, body weight, muscle weight, and marker for muscle metabolism were examined. Results: Weight gain was significantly greater in the TG-BG group (130.5%) than in the TG group (108.1%) at 15 wk (P < 0.05). The gastrocnemius muscle weight was significantly higher for TG-BG (2.84 g) than for TG (2.44 g) at 15 wk (P < 0.05). Western blotting indicated that atrogin-1 and MuRF1 levels were lower in the TG-BG group than in the TG group but were not suppressed in the TG-B or TG-G group. Conclusions: In a rodent sarcopenia model induced by TG, the administration of BCAA in combination with Gln more effectively inhibited muscle atrophy than the administration of BCAA or Gln alone. (C) 2019 Elsevier Inc. All rights reserved.