The application of microbore UPLC/oa-TOF-MS and 1H NMR spectroscopy to the metabonomic analysis of rat urine following the intravenous administration of pravastatin

The metabonomic effects of hepatotoxic doses of pravastatin on the urinary metabolic profiles of female rats have been investigated using ultra performance liquid chromatography (UPLC)–oa-TOF-MS and, independently, by 1H NMR spectroscopy. UPLC was performed using a 1 mm microbore column packed with 1.7 μm particles. Examination of the data obtained from the individual animals, aided by statistical interpretation of the data, made it possible to identify potential markers for toxicological effects, with both NMR and UPLC–MS analysis highlighting distinct changes in the urinary metabolite profiles. These markers, which included elevated taurine and creatine, as well as bile acids, were consistent with hepatotoxicity in some animals, and this hypothesis was supported by histopathological and clinical chemistry findings. The analytical data from both techniques could be used to define a metabolic “trajectory” as toxicity developed and to provide an explanation for the lack of hepatotoxicity for one of the animals. The two analytical approaches (UPLC–MS and NMR) were found to be complementary whilst the use of a 1 mm i.d. × 100 mm column reduced the amount of sample required for analysis to 2 μL, compared with 10 μL for a 2.1 mm i.d. × 100 mm column. The 1 mm i.d. column also provided increased signal-to-noise without loss of chromatographic efficiency.