Fig. 3.

Downregulation of PEPCK and G-6-Pase mRNA in primary rat hepatocytes by taurocholate is inhibited by pertussis toxin. Primary rat hepatocytes were prepared as described in “Materials and Methods.” After 20 h, cells were treated with either TCA (50 µM), insulin (50 nM), or both for a 4 h period, harvested at the same time, mRNA isolated and subjected to RT-PCR analysis to quantitate PEPCK and G-6-Pase mRNA as described in “Materials and Methods” (panels A and B). In some experiments, cells were treated 4 h after plating with pertussis toxin (300 ng/ml) for 16 h prior to treatment with TCA or insulin (panels C and D). N = 3 for all points. G-6-Pase, glucose-6-phosphatase; PEPCK, phosphoenolpyruvate carboxykinase; PTX, pertussis toxin; TCA, taurocholate.