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.