Influence on HMG-COA reductase inhibitors on plaque-forming cell (PFC) response in mice

Effects of pravastatin and simvastatin on the humoral immune response were studied using Cunningham's method of the IgM plaque-forming cell (PFC) assay system in mice. The vehicle (0.5% CMC), pravastatin (1 mg/body : about 50 mg/kg) or simvastatin (0.5 mg/body : about 25 mg/kg) were given orally for 14 days in experiment Exp-I and Exp-II. The vehicle, pravastatin (0.5 mg/body : about 25 mg/kg) or simvastatin (0.25 mg/body : about 12.5 mg/kg) were given orally 29 times for 32 days in Exp-III. There were no significant differences in the mean numbers of PFCs per 10(6) splenocytes between the pravastatin groups and the vehicle groups. In the simvastatin groups, however, there were significant reductions of the numbers of PFCs in Exp-I, Exp-II and Exp-III, as compared with the vehicle group. Based on these results, it was considered that suppressive effect on IgM antibody production was induced by simvastatin, whereas such a suppression was not observed with pravastatin.