Experimental Neurobiology

Table 3Tryptophan metabolites and enzyme activities in C57BL/6 mice of 3-month-old, 6-month-old and 8-month-old subjected to voluntary chronic aerobic exercise by inserting a running wheel in the cage for previous 1 month and without running wheel in control group

	3 months			6 months			8 months
	Control (n=9)	Exercise (n=5)	p-value	Control (n=9)	Exercise (n=5)	p-value	Control (n=10)	Exercise (n=5)	p-value
TRP (μM)	73.21 (52.42–79.91)	59.51 (53.72–68.31)	0.205	61.30 (48.96–72.92)	67.92 (58.10–73.09)	0.386	48.66 (46.96–55.78)	65.44 (62.97–80.75)	0.002^**
KYN (nM)	721.85 (661.10–962.23)	752.11 (641.41–855.37)	0.947	709.85 (575.13–850.09)	1026.35 (1021.55–1200.21)	0.014^*	527.34 (479.62–791.97)	704.56 (634.68–861.85)	0.178
3-HK (nM)	237.04 (132.26–341.89)	139.08 (94.15–156.26)	0.096	174.50 (152.72–239.92)	305.73 (246.41–351.50)	0.021^*	176.22 (131.66–252.39)	123.01 (95.79–160.28)	0.176
KYNA (nM)	66.54 (49.98–94.44)	68.55 (50.95–90.74)	1.000	32.69 (22.90–47.86)	148.57 (126.31–189.29)	0.003^**	39.12 (24.80–59.20)	88.73 (68.06–108.67)	0.007^**
KYN/TRP ratio	0.012 (0.009–0.014)	0.013 (0.011–0.014)	0.641	0.012 (0.010–0.013)	0.016 (0.014–0.020)	0.020^*	0.010 (0.009–0.015)	0.011 (0.009–0.012)	0.624
3-HK/KYN ratio	0.34 (0.20–0.37)	0.18 (0.14–0.18)	0.039^*	0.22 (0.21–0.37)	0.29 (0.24–0.34)	0.280	0.31 (0.27–0.36)	0.15 (0.10–0.23)	0.028^*
KYNA/KYN ratio	0.083 (0.072–0.114)	0.083 (0.069–0.112)	0.877	0.049 (0.030–0.066)	0.145 (0.111–0.181)	0.004^**	0.066 (0.036–0.097)	0.128 (0.101–0.155)	0.016^*
KYNA/3-HK ratio	0.31 (0.21–0.54)	0.46 (0.38–0.62)	0.217	0.21 (0.13–0.25)	0.56 (0.45–0.70)	0.005^**	0.21 (0.12–0.34)	0.66 (0.47–0.58)	0.032^*

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