1,4-DIHYDROXYNONENE MERCAPTURIC ACID, THE MAJOR END METABOLITE OF EXOGENOUS 4-HYDROXY-2-NONENAL, IS A PHYSIOLOGICAL COMPONENT OF RAT AND HUMAN URINE

In the present study 1,4-dihydroxynonene mercapturic acid (DHN-MA), pr eviously shown to be the major urinary metabolite of 4-hydroxy-2-nonen al (HNE) administered to the rat, was characterized and determined to be a normal constituent of rat and human urine. DHN-MA was excreted as a mixture of at least two stereoisomers as determined by ion trap LCM S/MS/MS after solid-phase extraction and HPLC purification. The 24-h u rinary excretion of this compound was about 10 ng and 5 mu g for rat a nd human, respectively. This end metabolite of the lipid peroxidation product HNE could represent a specific and noninvasive biomarker.