Importance of blood pressure variability in organ protection in spontaneously hypertensive rats treated with combination of nitrendipine and atenolol.
AIM
To study the importance of reduction of blood pressure variability (BPV) in the organ protection of long-term treatment with combination of nitrendipine and atenolol, which was abbreviated as Nile, in spontaneously hypertensive rats (SHR).


METHODS
Combination of nitrendipine (10 mg/kg/d) and atenolol (20 mg/kg/d) was given in SHR chow for 12 weeks. Blood pressure (BP) was then recorded during 24 h in conscious state. After the determination of baroreflex sensitivity (BRS), rats were killed for organ-damage evaluation.


RESULTS
Long-term treatment with Nile significantly decreased BP and BPV, ameliorated impaired BRS, and obviously diminished end-organ damage in SHR. The indices of left ventricular and aortic hypertrophy, and glomerulosclerosis score were all positively related to BP and BPV, and negatively related to BRS in untreated and Nile-treated SHR. Multiple-regression analysis showed that decrease in left ventricular and aortic hypertrophy was mainly related to the decrease in systolic BPV, and amelioration in renal lesion was mainly determined by increase in BRS.


CONCLUSION
Long-term treatment with Nile possessed obvious organ protection in SHR. Besides the BP reduction, the decrease in BPV and the restoration of BRS may importantly contribute to this organ protection.