Fig 1.
Two-way hierarchical clustering heatmap of plasma metabolome data.
Each column shows the metabolic pattern of individual animals in the control group (n = 5), food-restricted group (n = 5), and fatigued group (n = 6). The amount of each metabolite in individual samples is expressed as relative value obtained by the auto-scaling method and is represented by the color scheme in which red and blue indicate high and low concentrations of metabolites, respectively.
Fig 2.
Score and loading plots of principal component analysis of plasma metabolome CE-MS data.
(A) PCA score plot of PC2 versus PC1. The control group (n = 5), food-restricted group (n = 5), and fatigued group (n = 5) are shown as black, green, and red circles, respectively. Black ellipses represent the 90% confidence intervals for each group. (B) PCA loading plot of PC2 versus PC1. The data were analyzed after being mean-centered and variance scaled.
Table 1.
Plasma metabolite levels in fatigued animals.
Fig 3.
Supervised hierarchical clustered heatmap of 25 metabolites identified by one-way ANOVA.
Each column shows the metabolic pattern of individual animals in the control, food-restricted, and fatigued groups. The amount of each metabolite in individual samples is expressed as relative value obtained by the auto-scaling method and is represented by the color scheme in which red and blue indicate high and low concentrations of metabolites, respectively.
Fig 4.
Random forest analysis of the plasma metabolome.
The mean decrease in accuracy from the random forest analysis was used to rank metabolites according to their prognostic importance for fatigue status. The 15 most important metabolites among three groups (control, food-restricted, and fatigued) or two groups (fatigued and a combined control and food-restricted group) are shown in A and B, respectively.
Fig 5.
Relative concentrations of plasma metabolites related to the TCA cycle, urea cycle and proline metabolism, and BCAA metabolism.
Relative amounts of each metabolite in the control (C, n = 5), food-restricted (R, n = 5), and fatigued (F, n = 6) groups are shown and expressed as a percent of the control group. Data are presented as mean ± S.D. †P < 0.05, significantly different than the control group. §P < 0.05, significantly different between the food-restricted and fatigued group.
Fig 6.
ATP levels in the liver, brain, skeletal muscle, and erythrocytes.
Relative levels of ATP in each tissue in the control (C, n = 5–6), food-restricted (R, n = 5–6), and fatigued (F, n = 5–7) groups are shown and expressed as a percent of the control group. Data are presented as mean ± S.D. †P < 0.05, significantly different from the control group. §P < 0.05, significantly different between the food-restricted and fatigued group.
Fig 7.
Plasma NOx content in the control (C, n = 5), food-restricted (R, n = 6), and fatigued (F, n = 6) groups are shown. Data are presented as mean ± S.D. †P < 0.05, significantly different from the control group. §P < 0.05, significantly different between the food-restricted and fatigued group.