TABLE 3

Levels of 7β- and 16α-hydroxy-DHEA formed from incubations of various concentrations of expressed CYP3A4 and -3A7

Each incubation of expressed enzyme(s) was performed in duplicate at a final concentration of 50 μM DHEA. The production of hydroxylated DHEA metabolites was measured by LC-MS, and these amounts were then applied to a multivariate regression method to predict the concentrations of each enzyme. Details on incubation conditions, metabolite quantitation, and calculation of predicted enzyme concentrations are described under Materials and Methods.

Prepared Concentrationa
Metabolite Produced
Predicted Concentration
CYP3A4
CYP3A7
7β-OH DHEA
16α-OH DHEA
CYP3A4
CYP3A7
pmol/ml nmol pmol/ml
0.0 1.0 0.000 0.0210 0.0 0.3
0.0 2.5 0.000 0.131 0.1 1.7
0.0 5.0 0.011 0.304 0.4 3.9
0.0 7.5 0.014 0.612 0.6 7.8
0.0 9.0 0.014 0.556 0.5 7.1
0.0 10.0 0.015 0.775 0.6 9.8
0.0 40.0 0.041 3.542 −0.6 40.6
1.0 0.0 0.018 0.014 0.3 0.1
2.5 0.0 0.074 0.035 1.1 0.1
5.0 0.0 0.248 0.093 3.8 0.1
7.5 0.0 0.432 0.156 6.6 0.1
9.0 0.0 0.540 0.191 8.2 0.0
10.0 0.0 0.605 0.220 9.2 0.1
40.0 0.0 2.767 1.125 40.4 0.1
9.0 1.0 0.555 0.279 8.45 1.07
7.5 2.5 0.450 0.373 6.95 2.74
5.0 5.0 0.293 0.511 4.68 5.22
2.5 7.5 0.129 0.695 2.32 8.30
1.0 9.0 0.060 0.719 1.30 8.94
40 10 2.494 1.987 35.93 10.64
10
40
0.709
3.939
8.15
40.21

  • ↵ a The first 14 rows of data are from the calibration data set, and the remaining seven rows are data from the validation data set.