Table 1. Metabolites selected as biomarkers of pCPA-induced serotonin deficiency.
| Metabolite | HMDB ID | m/z | Representative MS/MS fragment ions (m/z)a | ESI+ |
ESI− |
||||
|---|---|---|---|---|---|---|---|---|---|
| Fold changeb | p valuec | VIPd | Fold changeb | p valuec | VIPd | ||||
| serotonin | HMDB00259 | 177.1009 | 160.0756, 132.0812, 115.0540* | −12.2 | 2.67 × 10−5 | 17.27 | |||
| 5-hydroxyindoleacetate | HMDB00763 | 192.0653 | 146.0595, 119.0484, 118.0656, 91.0566* | −4.5 | 9.24 × 10−6 | 12.76 | |||
| kynurenine | HMDB00684 | 209.0912 | 192.0653, 146.0596, 118.0650, 94.0656* | 2.8 | 1.28 × 10−5 | 9.21 | |||
| kynurenate | HMDB00715 | 190.0517 | 172.0407, 144.0455, 116.0511, 89.0402* | 1.8 | 4.98 × 10−5 | 8.34 | |||
| 3-hydroxykynurenine | HMDB00732 | 225.0866 | 190.0493, 162.0544, 110.0597* | 1.8 | 1.59 × 10−2 | 2.54 | |||
| phenylalanine | HMDB00159 | 166.0855 | 120.0806, 103.0549, 91.0542, 77.0396* | 2.3 | 6.29 × 10−6 | 19.22 | |||
| tyrosine | HMDB00158 | 182.0812 | 165.0548, 136.0753, 119.0491, 91.0541* | −1.6 | 5.22 × 10−4 | 6.52 | |||
| hippurate | HMDB00714 | 180.0650 | 105.0338, 77.0394, 51.0230* | 2.9 | 2.68 × 10−4 | 7.14 | 2.2 | 6.22 × 10−3 | 6.27 |
| creatinine | HMDB00562 | 114.0687 | 86.0741, 72.0480* | −3.7 | 9.22 × 10−3 | 4.87 | |||
| guanosine | HMDB00133 | 284.0983 | 152.0558, 135.0294, 110.0341* | 2.5 | 7.66 × 10−3 | 6.59 | |||
| hypoxanthine | HMDB00157 | 137.0457 | 119.0352, 110.0346, 94.0403, 55.0300* | 1.7 | 5.48 × 10−4 | 11.62 | |||
| 3-indolepropionic acid | HMDB02302 | 190.0857 | 130.0650, 103.0540, 77.0390, 55.0183* | −2.1 | 1.25 × 10−3 | 2.26 | |||
| lysoPC (18:4) | HMDB10389 | 516.3064 | 184.0730, 125.0001, 104.1067* | 2.1 | 3.64 × 10−4 | 6.77 | 1.5 | 4.32 × 10−5 | 5.79 |
| lysoPC (20:4) | HMDB10395/6 | 544.3387 | 184.0732, 104.1070, 86.0965* | 2.3 | 2.77 × 10−4 | 5.65 | 1.9 | 6.44 × 10−4 | 3.44 |
| lysoPC (22:6) | HMDB10404 | 568.3357 | 184.0730, 104.1068, 86.0966* | 1.8 | 6.43 × 10−5 | 3.27 | 1.7 | 1.42 × 10−3 | 5.67 |
| citrate | HMDB00094 | 191.0193 | 129.0187, 111.0088, 87.0089** | −2.0 | 5.12 × 10−5 | 7.27 | |||
| oxoglutarate | HMDB00208 | 145.0131 | 101.0235, 73.0293, 57.0347** | −1.7 | 8.22 × 10−3 | 6.63 | |||
| succinate | HMDB00254 | 117.0195 | 99.0086, 73.0298, 55.0191** | −1.6 | 1.29 × 10−2 | 6.94 | |||
| xanthine | HMDB00292 | 151.0253 | 108.0199, 80.0251, 65.9988** | −4.8 | 3.48 × 10−4 | 16.29 | |||
| uric acid | HMDB00289 | 167.0203 | 124.0147, 96.0204, 69.0100** | −6.3 | 6.22 × 10−5 | 23.64 | |||
| indoxyl sulfate | HMDB00682 | 212.0019 | 132.0451, 104.0502, 80.9653, 79.9576** | −3.3 | 7.22 × 10−3 | 9.54 | |||
aMetabolites labeled with * were confirmed by MS/MS in ESI+ mode, while metabolites labeled with ** were confirmed by MS/MS in ESI–mode.
bFold change was calculated from the arithmetic mean values of the pCPA group and the control group. Fold change with a positive value indicates a relatively higher concentration in the pCPA-treated mice, while a negative value indicates a relatively lower concentration compared with the control mice.
cP-values were determined by the Mann-Whitney U test.
dVIP denotes variable importance for projection where values larger than 2.00 reflects high contribution to the distinction between the pCPA group and the control group.