Fig. 2.

Activity of cytochrome P450 reductase in the HepatoPac model was shown to be stable in the HepatoPac model up through 22 days in culture. CPR activity was measured by pooling n = 12 samples at each time point or condition (vector control or siRNA treated) using donor 2. Activity levels were shown to be similar to the activity levels observed from two separate donor preparations of human hepatocytes and HLM samples. Although there was slightly lower activity observed after treatment of vector control or siRNA, most likely due to the difference in media supplementation for the delivery media, there was no difference between vector control and siRNA treatments, demonstrating that CPR activity is not impacted by reduction in CYP3A4 levels.