Standardization of acid hydrolysis procedure for urinary 3-methylhistidine determination by high-performance liquid chromatography.
The N-acetylated form of N-methylhistidine (3-methylhistidine, 3-meH), a non-invasive marker of proteolysis, accounts for 80-90% of total 3-meH excretion (acetylated+non-acetylated 3-meH) in the rat. To determine total 3-meH excretion, samples require acid hydrolysis prior to determination by high-performance liquid chromatography. This study evaluated the stability of 3-meH at various times and temperatures of hydrolysis and determined the optimal conditions for hydrolysis of samples. Increasing temperature (120 degrees C) results in significant degradation of 3-meH with no appreciable change in concentration being noted at 80 degrees C. Hydrolysis at 100 degrees C for 1.5 to 4 h or 80 degrees C for 8 to 12 h is recommended for determining total 3-meH concentrations in rat urine.
Kuhl
D A
DA
Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee, Memphis 38163, USA.
Methvin
J T
JT
Dickerson
R N
RN
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008762:Methylhistidines / Q000652:urine*; D051381:Rats; D013696:Temperature
D008762:Methylhistidines; C028118:3-methylhistidine