Alignment of metabolic trajectories with application to metabonomic toxicology

Abstract: Geometry of the metabolic trajectories is characteristic of the biological response (Keun, Ebbels et al. 2004). Yet, due to unavoidable inter-individual variations, the exact trajectories characterising the biological responses differ. We examined whether the differences seen between metabolic trajectories of a specific treatment, correspond to the variations seen in the other biological manifestations of the same treatment. Differences in trajectories were measured via alignment procedures which introduced and implemented in this study. Our study revealed strong correlation between the scales of the aligned trajectories of metabolic responses and the severity of the hepatocelluar lesions induced after administration of hydrazine. Thus the results confirm that aligned trajectories are characteristic of a specific treatment. They then can be used for comparison with other treatment specific or unknown metabolic trajectories and can have many metabonomic applications such as preclinical toxicological screening