Synergistic effects of atenolol and amlodipine for lowering and stabilizing blood pressure in 2K1C renovascular hypertensive rats.

AIM

To test the synergistic effects of atenolol and amlodipine on lowering blood pressure (BP) and reducing blood pressure variability (BPV) in 2-kidney, one-clip (2K1C) renovascular hypertensive rats.

METHODS

Forty-eight 2K1C renovascular hypertensive rats were randomly divided into 6 groups. They were respectively given 0.8% carboxymethylcellulose sodium (control), atenolol (10.0 mg/kg), amlodipine (1.0 mg/kg), and combined atenolol and amlodipine (low dose: 5.0+0.5 mg/kg; intermediate dose: 10.0+1.0 mg/kg; high dose: 20.0+2.0 mg/kg). The drugs were given via a catheter in a gastric fistula. BP was recorded for 25 h from 1 h before drug administration to 24 h after administration.

RESULTS

Compared with BP before medication, all 3 doses of combined atenolol and amlodipine significantly decreased the BP at 24 h after administration, except for the low dose on diastolic BP. Compared with the control group, all 3 doses of combined atenolol and amlodipine significantly reduced the average BP levels for the 24 h period after administration; furthermore, the high and intermediate doses also significantly decreased the BPV levels for the same period. The q values calculated by probability sum analysis for systolic and diastolic BP for the 24 h period after administration were 2.29 and 1.45, respectively, and for systolic and diastolic BPV for the same period they were 1.41 and 1.60, respectively.

CONCLUSION

There is significant synergism between atenolol and amlodipine in lowering and stabilizing BP in 2K1C renovascular hypertensive rats.