Arginine-enriched solution induces a marked increase in muscle glutamine concentration and enhances muscle protein synthesis in tumor-bearing rats.
Using a transplantable Yoshida sarcoma in a rat model of total parenteral nutrition (TPN), we measured the effectiveness of an arginine-enriched amino acid solution (AI-82) on muscle glutamine concentration and muscle protein synthesis compared with that of a conventional amino acid solution (Proteamin12). After tumor-bearing rats had been given one of two isocaloric TPN regimens for 6 days, [15N]glycine (99 atom %) containing TPN solution was infused into animals at a constant rate of 8 mg of [15N]glycine per hour for 18 hours, after which the liver, skeletal muscle (gastrocnemius muscle), and tumor protein synthesis rates were measured. A significantly increased whole muscle protein synthesis rate was observed in the AI-82 group; there was no difference in the whole liver and tumor protein synthesis rates between the two groups. When each TPN solution was administered for 1 week, muscle concentrations of arginine, ornithine, glutamine, and glutamate were considerably higher in the AI-82 group than in the Proteamin12 group, and these differences were also accompanied by a decrease in the plasma branched-chain amino acid (BCAA) (leucine, isoleucine, and valine) levels in the AI-82 group. The high levels of muscle glutamine concentration in the AI-82 group were investigated in connection with the high use of exogenous branched-chain amino acids.
Oka
T
T
Section of Biochemistry, Taiho Pharmaceutical Co Ltd., Tokushima, Japan.
Ohwada
K
K
Nagao
M
M
Kitazato
K
K
Kishino
Y
Y
D000597:Amino Acids, Branched-Chain / Q000097:blood; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism*; D008297:Male; D008762:Methylhistidines / Q000652:urine; D009124:Muscle Proteins / Q000096:biosynthesis*; D018482:Muscle, Skeletal / Q000378:metabolism*; D009368:Neoplasm Transplantation; D009952:Ornithine / Q000378:metabolism; D010289:Parenteral Nutrition, Total; D051381:Rats; D012517:Sarcoma, Yoshida / Q000628:therapy*
D000597:Amino Acids, Branched-Chain; D008762:Methylhistidines; D009124:Muscle Proteins; D005973:Glutamine; D018698:Glutamic Acid; D001120:Arginine; D009952:Ornithine; C028118:3-methylhistidine