TABLE 4.

Inhibition of 25OHD₃ 4-hydroxylation activity by CYP3A4 and HLM by DHB and KTZ

Experimental details are described under Materials and Methods.

	Recombinant CYP3A4		Human Liver Microsomes
	4β,25(OH)2D3	4α,25(OH)2D3	4β,25(OH)2D3	4α,25(OH)2D3
	% of control
DHB	0.34 ± 0.04	0.77 ± 0.19	2.61 ± 0.61	2.90 ± 0.04
KTZ	17.6 ± 3.38	18.5 ± 2.28	11.0 ± 1.82	18.5 ± 5.61