ABSTRACT
In this chapter, the authors present a rapid procedure for the separation of 21 amino acids of protein-free biological specimens by High-performance liquid chromatography method. They provide the experimental conditions for the resolution of histidine, 3-methylhistidine (3-MH), and 1-methylhistidine from other amino acids. Since the renal clearance of 3-MH is reduced in proportion to the reduction in glomerular filtration rate, the plasma levels of 3-MH are increased in patients with renal failure. However, excretion of 3-MH must equal its endogenous production plus the intake of 3-MH in the diet. The application of the method suggests that the use of 3-MH could be considered as a reliable nutritional parameter in assessing the rate of muscle protein breakdown in uremic patients provided that the patients are kept on a meat-free diet until an equilibrium is obtained.
