Fig. 2.

Metabolic pattern analysis by OPLS-DA score plot. A and B OPLS-DA score plot under positive- (A) and negative-ion modes (B). Blue circles indicate samples from the sham group (n = 6), and green circles indicate samples from the TAC group (n = 6). C and D Validated model plots obtained by permutation test: positive- (C) and negative-ion mode (D). OPLS-DA of the two-dimensional distribution patterns of the metabolites showed that in both positive- and negative-ion modes, significant separation of metabolite patterns was evident when the TAC group was compared with the sham group. The R² and Q² were 0.977 and 0.324 in positive modeand 0.993 and 0.435 in negative mode, respectively. OPLS-DA: orthogonal partial least squares discriminant analysis