Effect of branched-chain amino acid on 15N incorporation into liver and skeletal muscle proteins following [15N]-ammonium chloride administration to carbon tetrachloride-intoxicated rats.
The effect of branched-chain amino acid (BCAA) on protein synthesis and nitrogen metabolism in liver and skeletal muscle was evaluated by an intraperitoneal injection of [15N]ammonium chloride (15NH4Cl) to carbon tetrachloride (CCl4)-intoxicated rats. The 15NH4Cl was bolusly injected at a dose of 6 mg/100 g body weight one hour after an amino acid solution containing leucine and valine (150 mM each, abbreviated as BCAA), phenylalanine and alanine (150 mM each, PA), 120 mM leucine and 30 mM valine (Leu-rich) or 120 mM valine and 30 mM leucine (Val-rich) was administered intragastrially at a dose of 2.5 ml each/100 g body weight. The 15N-enrichment in the protein fraction of the liver was higher in CCl4-BCAA group than CCl4-PA group. The Leu-rich solution was found more effective in enhanced incorporation of 15N into liver and skeletal muscle proteins. The disappearance rate of [15N]urea from the plasma, which was influenced by the synthesis from 15NH3 and the excretion into urine, was much faster in the CCl4-BCAA group than CCl4-PA group. In Leu-rich group, both 15N incorporation into non-protein fraction of skeletal muscle and disappearance rate of plasma urea-15N were greater than those in Val-rich group. The results suggest that BCAA, particularly leucine, has beneficial effects on protein synthesis and ammonium detoxification in liver-injured rats.
Okita
M
M
Department of Food and Nutrition, Okayama Prefectural Junior College, Japan.
Watanabe
A
A
Tsuji
T
T
D000597:Amino Acids, Branched-Chain / Q000494:pharmacology*; D000643:Ammonium Chloride / Q000378:metabolism*; D000818:Animals; D002251:Carbon Tetrachloride; D056486:Chemical and Drug Induced Liver Injury; D005260:Female; D008099:Liver / Q000378:metabolism*; D008107:Liver Diseases / Q000378:metabolism*; D009124:Muscle Proteins / Q000096:biosynthesis*; D009584:Nitrogen / Q000378:metabolism*; D009587:Nitrogen Isotopes; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains
D000597:Amino Acids, Branched-Chain; D009124:Muscle Proteins; D009587:Nitrogen Isotopes; D000643:Ammonium Chloride; D002251:Carbon Tetrachloride; D009584:Nitrogen