In vitro metabolism studies using prepared human liver
microsomes or hepatocytes can provide useful data about the metabolism of NPS.
CYP2D6 is the principal cytochrome P450 responsible for the metabolism of histamine H1 antagonist promethazine in human liver
microsomes. Pharmacogenetics, : 449-457.
in 1975, (45,46) CYP21 from bovine adrenal cortex
microsomes by Kominami et al.
Similar to what has happened in the CYP-1A2 identification, in the present study, CYP-2C19 could be identified as LM target antigen when IB was performed with human liver
microsomes, although the IF was performed on rodent tissue.
The objectives of the present study included (1) to identify through ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) and high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-SPE-NMR) the WEL metabolites formed in rats following an oral administration of 50 mg/kg WEL; (2) to determine the uridine diphosphate-glucuronosyltransferases (UGTs) responsible for WEL glucuronidation using human liver
microsomes (HLMs), human intestine
microsomes (HIMs), human kidney
microsomes (HKMs), and recombinant human UGT enzymes; and (3) to explore the possible mechanisms of WEL regioselective glucuronidation.
We also used these values for [K.sub.m] and [v.sub.max] of the other metabolism pathways, as there were no ranges available for hepatic sulfation, and only pooled
microsomes had been used in the studies investigating gut glucuronidation.
Genistein could inhibit the activity of liver
microsomes, and celecoxib plasma levels were increased by decrement on metabolism of celecoxib with genistein.
For Western blotting,
microsomes (5 [micro]g) were size-separated by 10% SDS-polyacrylamide gels and transferred onto nitrocellulose membranes.
Very recently, using in vitro microsomal incubation systems, we systematically studied the metabolites of DIC in human and animal liver microsomal incubation systems [14], and we found that the metabolic fate of DIC in human liver
microsomes was about the same as that in mouse liver
microsomes, while with some differences compared with that in rat, dog, and monkey liver
microsomes.
Incubation with Rat
Microsomes. Samples for incubation were prepared with 50 [micro]M alantolactone or isoalantolactone, 5 mM Mg[Cl.sub.2], 1 mM NADPH, and 1 mg/mL microsomal protein in potassium phosphate buffer (0.1 M, pH 7.4).
The livers were removed immediately and washed in ice-cold water and the
microsomes were prepared, as described previously.
(13) showed that ritonavir is metabolized by CYP 3A4 and CYP 3A5 at the same ratio, but indinavir is metabolized by CYP 3A4 than CYP 3A5 in human intestinal
microsomes and expressed CYP 3A4/3A5.
