Inhibition of the hypoxia-dependent PAI-1 mRNA induction by ActD and cycloheximide in primary rat hepatocyte cultures. Hepatocytes were cultured as in Fig 1. (A) The cells were then treated for 30 minutes with ActD (1 μg/mL) or cycloheximide (CHX; 10 μg/mL) before they were placed under hypoxia for 3 hours. A total of 15 μg total RNA was subjected to Northern analysis. In each experiment, the PAI-1 mRNA level measured by Northern blotting (cf B) under normoxia (16% O2) was set equal to 100%. The induction of PAI-1 mRNA by cycloheximide under normoxia was due to a stabilization of PAI-1 mRNA.11 Values ± SEM represent the fold induction of PAI-1 mRNA of 3 independent experiments. Statistics, Student'st-test for paired values: significant differences * 16% O2 versus 8% O2, ** 8% O2 versus ActD, P ≤ .05. (B) Representative Northern blot.
