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Published on: September 18, 2017
Effect of ranolazine on cardiac microcirculation in normal and diabetic rats
H Khazraei1, M Shafa2, Hossein Mirkhani3
1Shiraz University of Medical Sciences Department of Pharmacology PO Box 71345-1649 Shiraz Iran.
Unlabelled:
Ranolazine is a new antianginal drug that is postulated to act through blocking of cardiac late sodium channels and improvement in cardiac blood flow. The present study has been carried out to investigate its possible effect on microcirculation of normal and diabetic rats’ cardiac muscle.
Methods:
Normal and diabetic rats were anesthetized.The chest was opened and a surface laser Doppler flowmeter probe was sutured on the left ventricle next to the left anterior descending branch of the coronary artery. After 30 minutes of animal adaptation, baseline flow was recorded.Thereafter, ranolazine was injected intravenously (10 mg/kg) through the jugular vein and the changes in the cardiac blood flow were measured every 5 minutes for 30 minutes. Systolic blood pressure and heart rate were also recorded.
Results:
Although, injection of ranolazine resulted in some reduction of cardiac blood flow, no significant changes were observed in normal and diabetic animals. Ranolazine had no significant effect on systolic blood pressure of either groups studied. Nevertheless, it caused a mild but statistically significant increase in the heart rate of diabetic and normal rats.
Conclusion:
In conclusion, in normal and diabetic rats, no evidence of improvement in intramyocardial blood flow by ranolazine was obtained.
Insights
Ranolazine did not improve cardiac blood flow in normal or diabetic rats, despite its proposed mechanism. The antianginal drug showed no significant effect on blood pressure but mildly increased heart rate.
Area of Science:
- Cardiology
- Pharmacology
- Physiology
Background:
- Ranolazine is an antianginal medication.
- It is believed to work by blocking cardiac late sodium channels.
- This action may improve cardiac blood flow.
Purpose of the Study:
- To investigate ranolazine's effect on cardiac microcirculation.
- The study included both normal and diabetic rats.
- This research aimed to understand ranolazine's impact on myocardial blood flow.
Main Methods:
- Anesthetized normal and diabetic rats were used.
- Laser Doppler flowmetry measured cardiac blood flow in the left ventricle.
- Ranolazine was administered intravenously, and hemodynamic parameters were recorded.
Main Results:
- Ranolazine administration did not significantly alter cardiac blood flow in either group.
- No significant changes in systolic blood pressure were observed.
- A mild, statistically significant increase in heart rate was noted in both normal and diabetic rats.
Conclusions:
- Ranolazine did not demonstrate improvement in intramyocardial blood flow.
- The study found no evidence supporting ranolazine's efficacy in enhancing cardiac blood flow in this model.
- Further research may be needed to elucidate ranolazine's precise effects on cardiac circulation.

