TABLE 2

Kinetic parameters obtained for each compound in microsomes and hepatocytes

P450	Substrate	K_M,u (or S_50,u)			V_max			CL_int,u
P450	Substrate			Cryopreserved Human Hepatocytes	Human Liver Microsomes	Cryopreserved Human Hepatocytes	Human Liver Microsomes	Cryopreserved Human Hepatocytes	Human Liver Microsomes
		μM			nmol/min/10⁶ cells or mg protein			μl/min/10⁶ cells or mg protein
CYP2C9	Tolbutamide methylhydroxylation	112 ± 38	212 ± 90	0.015 ± 0.002	0.37 ± 0.08	0.06 ± 0.03	1.9 ± 0.4
	Diclofenac 4′-hydroxylation	7.4 ± 0.7	3.7 ± 0.4	0.29 ± 0.20	1.8 ± 0.3	38 ± 23	501 ± 28
	S-Warfarin 7-hydroxylation	2.7 ± 1.5	4.3 ± 0.02	0.001 ± 0.001	0.004 ± 0.001	1.0 ± 1.0	0.87 ± 0.22
CYP2C19	S-Mephenytoin 4′-hydroxylation	13 ± 4	30.3	0.016 ± 0.004	0.04	1.4 ± 0.7	1.37
CYP3A4	Quinidine (3S)-3-hydroxylation	50 ± 8	78	0.31 ± 0.33	0.88	7.0 ± 7.9	11
	Nifedipine oxidation	16 ± 12	11	1.07 ± 1.15	0.95	56 ± 26	87
	Testosterone 6β-hydroxylation	24 ± 1^a	47^a	1.8 ± 1.3	6.1	31 ± 22	131
	Terfenadine methylhydroxylation	0.49 ± 1.73	1.0 ± 0.5	91 ± 57	43 ± 14	1410 ± 590	11,100 ± 275
	Terfenadine N-dealkylation	1.7 ± 1.2	0.8 ± 0.02	21 ± 8	2.8 ± 0.4	154 ± 102	90 ± 13
	Dextromethorphan N-demethylation^b	139 ± 88	221 ± 50	0.28 ± 0.24	0.61 ± 0.1	2.8 ± 2.5	2.8 ± 0.3
CYP2D6	Bufuralol 1-hydroxylation	2.1 ± 1^c	2.8^c	0.028 ± 0.016^c	0.071^c	17 ± 15^c	26^c
		44 ± 39^d	43.3^d	0.027 ± 0.002^d	0.076^d	0.98 ± 0.65^d	1.8^d
	Dextromethorphan O-demethylation^e	0.9 ± 0.3^c	2 ± 0.4^c	0.05 ± 0.03^c	0.134 ± 0.01^c	63 ± 46^c	69 ± 16^c
		44 ± 15^d	106 ± 55^d	0.06 ± 0.017^d	0.16 ± 0.03^d	1.6 ± 0.90^d	1.72 ± 0.5^d