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[The effect of ouabain on the cardiovascular system of rats with chronic heart failure]
Abstract:
The response of the rat cardiovascular system to the cardiac glycoside ouabain was studied in an original model of heart failure developed on day 21 of coronary embolization with 15 microns radioactive microspheres introduced into the left ventricular cavity during ascending aortic occlusion. To examine systemic and regional hemodynamic parameters, the tracer technique with microspheres. Ouabain infused to rats with heart failure caused an increase in the index of left ventricular contractility, cardiac output, stroke volume, myocardial contractility, blood flow in most viscera and a decrease in end-diastolic pressure. The findings suggest that 21 days after coronary embolization the rats with heart failure proved more sensitive to the glycoside than did those sham-operated and thus, the presented model adequately reflects the status of the cardiovascular system when heart failure is evolving.
Insights
Rats with heart failure showed increased sensitivity to ouabain, a cardiac glycoside. This study utilized a novel heart failure model in rats to assess cardiovascular responses to ouabain.
Area of Science:
- Cardiovascular Physiology
- Pharmacology
- Animal Models
Background:
- Heart failure is a complex condition affecting cardiovascular function.
- Cardiac glycosides like ouabain have inotropic effects.
- Developing reliable animal models is crucial for studying heart failure pathophysiology.
Purpose of the Study:
- To investigate the cardiovascular system's response to ouabain in a rat model of heart failure.
- To compare the effects of ouabain in heart failure rats versus sham-operated controls.
- To validate a novel heart failure model for studying drug responses.
Main Methods:
- A rat model of heart failure was created using coronary embolization with radioactive microspheres.
- Systemic and regional hemodynamic parameters were assessed using the microsphere tracer technique.
- Ouabain was infused into rats with established heart failure and control groups.
Main Results:
- Ouabain administration increased left ventricular contractility index, cardiac output, and stroke volume in heart failure rats.
- Myocardial contractility and blood flow to most viscera were enhanced by ouabain.
- End-diastolic pressure decreased, and heart failure rats showed greater sensitivity to ouabain compared to controls.
Conclusions:
- The developed rat model of heart failure is sensitive to cardiac glycoside intervention.
- Ouabain demonstrates significant positive inotropic and hemodynamic effects in this evolving heart failure model.
- The findings support the utility of this model for studying cardiovascular drug efficacy in heart failure.