| RESEARCH PAPER |
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| Year : 1997 | Volume
: 29
| Issue : 5 | Page : 310-313 |
Effect of metoprolol and prazosin alone and in combination in reperfusion induced arrhythmias in intact rabbits
D Sharma, P Pandhi
Correspondence Address:
D Sharma
 Source of Support: None, Conflict of Interest: None  | Check |
Objective: To investigate the effect of metoprolol (cardioselective beta blocker), prazosin (alpha blocker) alone and in combination on reperfusion induced arrhythmias in intact rabbit hearts.
Methods: Newzealand white rabbits of either sex weighing 1.5 to 2 kg were used. The coronary artery was ligated for 30 minutes and then reperfusion was carried out for 60 minutes. Metoprolol alone (0.5 mg, 0.75 mg and 1mg/kg B.wt.), prazosin alone (0.25 mg, 0.5 mg and 1mg/kg B.wt.) and combination of lowest dose of metoprolol (0.5 mg/kg) and prazosin (0.25 mgkg) was administered intravenously at the time of reperfusion in different groups of animals. Electrocardiogram was monitored every 5 minutes using limb lead II throughout the experiment. Incidence and severity of arrhythmias were analysed from ECG recordings.
Results: Metoprolol in all doses produced slight bradycardia and percent protection against arrhythmias was 0 to 16.6% with different doses.Percent protection produced by prazosin was 33.3 to 66.6%. When metoprolol (lowest dose) was used in combination with prazosin (lowest dose) there was no change in heart rate and percent protection against arrhythmias was 83.3%.
Conclusion: Combination of a cardioselective beta blocker (metoprolol) and an alpha blocker (prazosin) has produced potentiation of effect in protecting the heart against reperfusion induced arrhythmias in intact rabbit heart.
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