NOx production of primary human hepatocytes and its inhibition by proteasome
inhibitors. Primary human hepatocytes were cultured for 3 days after
delivery and treated with 1 mM PB for an additional 2 days. PB was
maintained in the media during treatments. NOx was measured from media after
treatment. A, hepatocytes (HH1390) were treated with ILmix (2.5 ng/ml
IL-1β, 5 ng/ml TNF-α, and 5 ng/ml
IFN-γ), the proteasome inhibitor MG132 (10 μM), or
both for 18 h. B, hepatocytes (HH1402) were treated with ILmix, the
proteasome inhibitor lactacystin (10 μM), or both or
ILmix/lactacystin (10 μM) for 18 h. C, concentration dependence
of the effects of proteasome inhibitors on NOx production. PB-treated
hepatocytes (HH1395) were cotreated with ILmix and various concentrations of
lactacystin (Lac) or epoxomicin (Epoxo) for 18 h, and 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.