Table 1

P450 contents and substrate oxidation activities of liver microsomes of three human samples

P450	HL-C6	HL-C15	HL-C19
P450	(pmol P450/mg protein)
Total P450	660	420	690
CYP2C19	4.9	14.4	8.7
CYP3A4	480	58	320

Substrate oxidation		(pmol product formed/min/mg protein)
S-Mephenytoin 4′-hydroxylation	(400 μM)^1-a	31	90	59
Testosterone 6β-hydroxylation	(200 μM)^1-a	4700	580	3100

Omeprazole 5-hydroxylation	(10 μM)^1-a	340	210	210
	(400 μM)^1-a	1800	610	1030
	(Ratio)^1-b	(0.19)	(0.34)	(0.20)

Omeprazole sulfoxidation	(10 μM)^1-a	270	53	150
	(400 μM)^1-a	2000	410	1100
	(Ratio)^1-b	(0.14)	(0.13)	(0.14)

↵1-a Substrate concentrations.
↵1-b Ratio of activities of omeprazole oxidation when determined at substrate concentrations of 10 and 400 μM.