Effects of Combination Therapy with Levamlodipine and Bisoprolol on Stroke in Rats

Aim To examine the effects of combination with levamlodipine and bisoprolol on stroke in rats. Methods For acute study, Systolic blood pressure (SBP) and heart period (HP) were monitored in conscious stroke prone-spontaneously hypertensive rats (SHR-SP) and sinoaortic denervation (SAD) rats before and after intragastric administration of either drug at a single dose. Rats were subjected to middle cerebral arterial occlusion (MCAO) half an hour after drug administration; sacrificed 24h later to measure the infarct size. For long-term study, drugs (either alone or in combination) were delivered via food to SHR-SP. The survival time was recorded. Results SBP was significantly reduced by combination therapy both in SHR-SP and SAD rats. Neutralization on heart rate (HR) was observed in combination. The drug combination increased baroreflex sensitivity (BRS) and reduced SBP variability (SBPV). In chronic experiments, the lifespan of SHR-SP rats exposed to the drug combination was longer than that in rats exposed to either drug alone. The infarct area was the smallest in subjects receiving drug combination in SD rats both with and without SAD. Conclusion Combined use of levamlodipine and bisoprolol produced better protection against stroke.