Triazolam

The basic incubation mixture contained liver or intestinal microsomes, 100 mM potassium phosphate buffer (pH 7.4), 0.1 mM EDTA, NADPH generating system, and 200 µM triazolam (Wako Pure Chemicals, Osaka, Japan) as a CYP3A substrate. Incubation was conducted at 37 °C for 30 min (intestine) or 60 min (liver) and terminated by adding acetonitrile. After centrifugation, the supernatant was analyzed by HPLC.

The drugs used were modafinil (Modiodal; Alfresa Pharma Co.) and triazolam (205-14221; Fujifilm Wako Pure Chemical Corp., Osaka, Japan). The drug doses used in this study were the same as those recommended in previous reports [22 (link), 23 (link), 24 (link), 25 (link)]. Each drug was suspended in 0.5% (w/v) methylcellulose (131-17811; Fujifilm Wako Pure Chemical Corp.). The modafinil or a vehicle was injected with a nasogastric tube 30 min before the dark period (at 18:30). The triazolam or a vehicle was injected with a nasogastric tube 3 h after the lights were turned on (at 10:00). Each animal was given a single dose of one drug/vehicle (only) on each experimental day. Each drug or vehicle was administered at intervals of at least 7 days.