Glutamine: a precursor of glutathione and its effect on liver

AIM:To investigate the relationship between alanyl-glutamine (ALA-GLN) and glutathione (GSH) biosynthesis in hepatic protection.METHODS:Twenty male Wistar rats were randomly divided into two groups:one receiving standard parenteral nutrition (STD) and the other supplemented with or without ALA-GLN for 7 days. The blood and liver tissue samples were examined after 5-fluorouracil (5-FU) was injected peritoneally.RESULTS:The concentration measurements were significantly higher in ALA-GLN group than in STD group in serum GLN (687&mgr;mol/L plus minus 50&mgr;mol/L vs 505&mgr;mol/L plus minus 39&mgr;mol/L, P < 0.05), serum GSH (14&mgr;mol/L plus minus 5&mgr;mol/L vs 7&mgr;mol/L plus minus 3&mgr;mol/L, P <0.01) and in liver GSH content (6.9&mgr;mol/g plus minus 2.5&mgr;mol/g vs 4.4&mgr;mol/g plus minus 1.6&mgr;mol/g liver tissue, P <0.05). Rats in ALA-GLN group had lesser elevations in hepatic enzymes after 5-FU administration.CONCLUSION:The supplemented nutrition ALA-GLN can protect the liver function through increasing the glutathione biosynthesis and preserving the glutathione stores in hepatic tissue.