Applications of metabolomics and proteomics to the mdx mouse. (a) A typical high-resolution 1H NMR spectrum from an aqueous extract of cardiac tissue from the mdx mouse. The chemical shift and splitting pattern of a given resonance (peak) enables the identification of the metabolite it belongs to, and the area under the resonance determines the concentration of that metabolite. (b) An orthogonal signal corrected partial least squares discriminate analysis plot of various mouse models of cardiac disease using solution state NMR spectroscopy. Key: circles, control + mdx; diamonds, model of cardiac hypertrophy (MLPKO); squares, model of cardiac arrhythmia (Scn-/+); triangles, model of cardiac arrhythmia (ScnΔ /+). (c) Correlation analysis between identified proteins in a proteomic study of heart tissue from mdx mice and the intracellular concentration of taurine. When detected by 1H NMR spectroscopy (bottom graph), taurine can be identified by two triple peaks at δ 3.25-3.27 and δ 3.42-3.46. The correlation heat map between spectral intensity and protein expression was used to determine which proteomic changes were associated with the increase in taurine in dystrophic muscle. The x axis is the chemical shift region containing the resonances from taurine; the y axis consists of protein spots detected in the two-dimensional gel electrophoresis. The color scale displays the correlation coefficients between the two sets of data (concentration of taurine against concentration of protein).