Experimental Neurobiology

Table 2Tryptophan metabolites and enzyme activities in C57BL/6 mice of 3-month-old, 6-month-old and 8-month-old which are fed a high-fat diet for previous 1 month and fed an ordinary diet in control group

	3 months			6 months			8 months
	Control (n=9)	High-fat diet (n=5)	p-value	Control (n=9)	High-fat diet (n=5)	p-value	Control (n=10)	High-fat diet (n=5)	p-value
TRP (μM)	73.21 (52.42–79.91)	49.78 (47.30–58.00)	0.072	61.30 (48.96–72.92)	67.63 (54.53–77.50)	0.549	48.66 (46.96–55.78)	83.17 (77.93–87.97)	0.002^**
KYN (nM)	721.85 (661.10–962.23)	418.46 (399.40–452.64)	0.003^**	709.85 (575.13–850.09)	681.99 (628.92–719.93)	0.841	527.34 (479.62–791.97)	578.73 (545.83–1160.83)	0.178
3-HK (nM)	237.04 (132.26–341.89)	104.83 (91.27–116.19)	0.028^*	174.50 (152.72–239.92)	106.81 (85.02–150.69)	0.096	176.22 (131.66–252.39)	76.49 (64.07–120.21)	0.221
KYNA (nM)	66.54 (49.98–94.44)	47.14 (35.79–58.94)	0.072	32.69 (22.90–47.86)	46.65 (41.32–63.44)	0.021^*	39.12 (24.80–59.20)	48.70 (44.13–57.49)	0.028^*
KYN/TRP ratio	0.012 (0.009–0.014)	0.008 (0.008–0.009)	0.006^**	0.012 (0.010–0.013)	0.010 (0.008–0.013)	0.257	0.010 (0.009–0.015)	0.007 (0.006–0.014)	0.221
3-HK/KYN ratio	0.34 (0.20–0.37)	0.24 (0.21–0.27)	0.162	0.22 (0.21–0.37)	0.16 (0.12–0.20)	0.053	0.31 (0.27–0.36)	0.09 (0.08–0.11)	0.903
KYNA/KYN ratio	0.083 (0.072–0.114)	0.104 (0.088–0.137)	0.257	0.049 (0.030–0.066)	0.070 (0.061–0.094)	0.045^*	0.066 (0.036–0.097)	0.074 (0.052–0.086)	0.011^*
KYNA/3-HK ratio	0.31 (0.21–0.54)	0.45 (0.39–0.51)	0.257	0.21 (0.13–0.25)	0.45 (0.33–0.67)	0.005^**	0.21 (0.12–0.34)	0.70 (0.51–0.74)	0.018^*

Data presented as median and interquartile range. TRP indicates tryptophan; KYN, kynurenine; 3-HK, 3-hydroxylkynurenine; KYNA, kynurenic acid.

p-values were provided by Mann-Whitney U test. ^*p < 0.05, ^**p < 0.01.

Exp Neurobiol 2017;26:132~140 https://doi.org/10.5607/en.2017.26.3.132