Evaluation of high trough-to-peak ratio of perindopril in SHR.

The present study was designed to evaluate trough-to-peak ratio (T/P) of AC E inhibitors in spontaneously hypertensive rats (SHR) by a continuous monit oring of ambulatory blood pressure for 24 hours with a biotelemetric system . Blood pressure was recorded uninterruptedly with a battery-operated trans mitter connected to a sensor catheter. Perindopril (3 mg/kg), trandolapril( 1 mg/kg), quinapril(10 mg/kg) and enalapril (6 mg/kg) were given once a day for 7 days. On the first day of the treatment these ACE inhibitors equally decreased blood pressure by 20 mmHg at each peak. The peak and trough bloo d pressure decreased steadily until day 4, and then they were constant unti l the end of experiment (day 7). T/P for each inhibitor also increased unti l day 4, and the ratios in systolic blood pressure at the end of experiment s (day 7) were as follows, perindopril: 0.63, trandolapril: 0.62, quinapril : 0.41, enalapril: 0.27. The T/P of perindopril was significantly higher th an that of enalapril. The results of the present studies testing four ACE i nhibitors are well consistent with those in clinical trials. Thus, the meas urement of T/P in SHR would provide a meaningful information for the evalua tion of antihypertensive agents like ACE inhibitors.