TABLE 3

Metabolite formation by rat intestinal slices and rat intestinal microsomes Substrates (100 μM; testosterone, triazolam, quinidine, lidocaine, carbamazepine, verapamil, and midazolam) were incubated with both rat intestinal slices and rat intestinal microsomes. Results are means of individual slices (three separate experiments, n = 3 slices each) or individual microsome incubations (two separate experiments, n = 3 incubations each) ± S.E.M. Results from intestinal microsomes were corrected using the scaling factor between microsomes and slices (see text).


Metabolites Measured

Microsomes

Microsomes (after Scaling)

Slices

Ratio Slices/Microsomes
pmol/min/mg microsomal protein pmol/min/mg total intestinal protein pmol/min/mg total intestinal protein
Androstenedione 425 ± 25 21 ± 1.2 126 ± 25 6.0
MEGX 76 ± 9.6 3.8 ± 0.5 101 ± 14 27
6β-TOH 110 ± 16 5.5 ± 0.8 25 ± 2.0 4.5
16α-TOH 41 ± 6.7 2.0 ± 0.4 7.8 ± 0.81 3.9
16β-TOH 46 ± 8.4 2.3 ± 0.4 10 ± 1.3 4.3
Nor-verapamil 171 ± 27 8.5 ± 1.3 53 ± 7.5 6.2
3-OH-Quinidine 61 ± 1.0 3.0 ± 0.05 88 ± 7.8 29
1-OH-Triazolam 108 ± 3.0 5.4 ± 0.1 17 ± 3.5 3.1
4-OH-Midazolam 80 ± 15 4.0 ± 0.8 11 ± 3.0 2.8
1-OH-Midazolam 114 ± 17 5.7 ± 0.9 26 ± 6.4 4.6
Carbamazepine epoxide
14 ± 3.0
0.7 ± 0.1
5.5 ± 0.98
7.9