Amino acids in the rat liver and plasma and some metabolites in the liver after sodium benzoate treatment

The effect of sodium benzoate administration on amino acids in the liver and plasma and various metabolites in the liver was studied. Changes in glutamine and ornithine were noted only at a higher dose (10 mmol/kg body wt) of benzoate, whereas even a lower dose caused a significant decrease in glycine, serine, and alanine levels of plasma and liver. A dose- and time-dependent decrease in glycine levels was studied. A decrease of up to 50% in the glycine concentration may limit its own transport into mitochondria and availability for the formation of hippurate. A decrease in alanine may have resulted from stimulation of gluconeogenesis from alanine, by increased ammonia. Among the metabolites studied, ATP and acetyl-CoA decreased and ammonia increased significantly even at a lower dose (5 mmol/kg body wt) of benzoate. The compounds that require ATP for their synthesis such as N-acetylglutamate and glutamine decreased significantly only at the higher dose of benzoate, whereas urea and glutathione levels were unaffected under our experimental conditions.