TABLE 1

Kinetics of phenytoin hydroxylation by HLM- and E. coli-expressed CYP2C9 in the presence and absence of 2% albumin Units: HLM, K_m, micromolar; V_max, picomoles per minute per milligram; CL_int, microliters per minute per milligram. E. coli-expressed CYP2C9: K_m, micromolar; V_max, picomoles per minute per picomole of P450; CL_int, microliters per minute per milligram. CL_int.liver, liters per hour.

Enzyme Source	Parameter	No Albumin	BSA	HSA-FAF	HSA
HLM	K _m	20.8 ± 1.5	4.7 ± 0.3^*	4.7 ± 0.2^*	26.5 ± 1.0^*
	V _max	17.8 ± 0.3	20.2 ± 0.5^*	20.7 ± 0.8^*	17.4 ± 0.3
	CL_int	0.86 ± 0.05	4.3 ± 0.3^*	4.5 ± 0.1^*	0.66 ± 0.02^*
	CL_int.liver	2.93 ± 0.16	14.85 ± 0.87^*	15.39 ± 0.32^*	2.25 ± 0.07^*
CYP2C9	K _m	14.4 ± 1.3	3.6 ± 0.2^*	4.1 ± 0.2^*	14.7 ± 0.1
	V _max	0.230 ± 0.006	0.246 ± 0.001^*	0.249 ± 0.004^*	0.236 ± 0.003
	CL_int	1.17 ± 0.07	4.99 ± 0.22^*	4.49 ± 0.13^*	1.17 ± 0.02
	CL_int.liver	4.01 ± 0.24	17.06 ± 0.75^*	15.36 ± 0.43^*	3.99 ± 0.06

↵* Significantly different (p < 0.05) from control value (determined in the absence of albumin)