Table 3.

Brain tissue concentrations of Ket and (2,6)-HNK metabolites after i.v. administration to Wistar rats (20 mg/kg) of (2S,6S)-HNK, (S)-Ket, and (R)-Ket and the ratio of brain tissue concentration: plasma concentration of the analytes presented in the parenthesis under the brain tissue concentrations.

Protocol	Compound	10 min	20 min	60 min
(2S,6S)HNK	(2S,6S)-HNK	30,463 ± 8412	29,256 ± 41442	6117 ± 21162
		(2.5)	(3.5)	(2.2)
(S)-Ket	(S)-Ket	15,512 ± 453	7044 ± 3915	5643 ± 4125
		(5.7)	(7.0)	(12.3)
	(2S,6S)-HNK	657 ± 501	760 ± 1211	769 ± 1331
		(0.9)ns	(0.6)ns	(1.2)ns
	(2S,6R)-HNK	103 ± 5	46 ± 28	BQ
		(0.6)	(0.7)
(R)-Ket	(R)-Ket	16,365 ± 1931	8715 ± 4433	5224 ± 3391
		(4.8)	(6.1)	(10.5)
	(2R,6R)-HNK	274 ± 47	191 ± 50	156 ± 34
	(0.8)	(0.6)	(0.8)
	(2R,6S)-HNK	141 ± 20	78 ± 37	48 ± 28
		(0.6)	(0.8)	(1.4)

The results are presented as ng/g tissue with n = 3 for each data point (±SD). ^nsNo statistically significant differences between the ratio of brain tissue concentration: plasma concentration of (2S,6S)-HNK and (2R,6R)-HNK observed after administration of (S)-Ket and (R)-Ket, respectively.

¹Statistically significant difference (P < 0.005) between the brain tissue concentrations of (2S,6S)-HNK and (2R,6R)-HNK observed after administration of (S)-Ket and (R)-Ket, respectively.

²Data obtained from Paul et al. (2014).