Effect of pretreatment with PB and RIF on the efficacies of proteasome
inhibitors. A, primary human hepatocytes (HH1417) were cultured for 3 days
after delivery and treated with or without 1 mM PB or 50 μM
rifampicin for an additional 2 days. PB or RIF were maintained in the media
during treatments. Hepatocytes were treated with vehicle (mock), ILmix, or
ILmix/MG132 (20 μM), and NOx was measured in the media 20 h
after treatment. B, bortezomib efficacy on NOx production. Two different
human hepatocyte preparations (HH1422 and HH1425) were pretreated with 1 mM
PB for 2 days and then treated with vehicle ILmix, ILmix and MG132 (10
μM), or ILmix and bortezomib (Bort, 10 μM) for 18 h.
NOx was measured in the media. Values are the mean ± S.D. of
three independent samples. a, significantly different from control; b,
significantly different from ILmix alone, P <
0.05. Con, control.