Administration time–dependent effect of nitrendipine on the reduction of cardiac hypertrophy in spontaneously hypertensive rats

The influence of administration time of nitrendipine on the regression of cardiac mass was studied in spontaneously hypertensive rats (SHR). Nitrendipine (100 mg/kg) was given once daily at 10 or 10 for 16 weeks. Similar reductions of the trough blood pressure were observed in both groups. Cardiac biventricular mass in the animals dosed at 10 was significantly less than that in the vehicle-treated rats, whereas in the rats dosed at 10 no significant reduction was noted in the cardiac mass. These data suggest that the administration time of nitrendipine has a different effect on the regression of cardiac hypertrophy in SHR.