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 , 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.