A comparison of inhibition of pravastatin on HMG-CoA reductase with enalapril and verapamil in SDR and SHR liver

AIM To compare the inhibition of pravastatin on HMG CoA reductase with enalapril and verapamil in SDR and SHR liver. METHODS The liver microsomes were prepared by ultracentrifugation, the HMG CoA reductase activity was determined by radioactivity in vitro. RESULTS Pravastatin inhibited HMG CoA reductase, and its IC 50 value was 0 28 g·L -1 . The inhibitory rate of pravastatin on HMG CoA reductase in SDR and SHR liver were 51 40%±3 98% and 63 40%±4 14%, respectively (P001). Enalapril and verapamil did not inhibit HMG CoA reductase. The inhibitory rate of enalapril and verapamil on HMG CoA reductase in SDR and SHR liver were -0 33%±13 35%, 5 90%±21 12% and 2 60%±17 38%,4 00%±19 69%, respectively. Enalapril and verapamil were significantly different from pravastatin p0 01). CONCLUSION The inhibitory effects of pravastatin on HMG CoA reductase in SHR were more potent than that in SDR, while enalapril and verapamil did not inhibit activity of HMG CoA reductase. These results suggest that pravastatin greatly prevents the synthesis of cholesterol, decreases serum cholesterol in SHR, and it is in favor of the therapy of hypertension. The inhibitory mechanism of enalapril and verapamil on serum lipoprotein is irrelevant of HMG CoA reductase in SDR and SHR liver.