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Effect of glutathione on canine myocardial ischaemia without reperfusion
1Departament de Fisiología, Facultat de Medicina i Odontologia, Universitat de València, Spain.
Insights
Exogenous glutathione showed minor benefits in reducing myocardial damage from short-term coronary occlusion in dogs. However, it did not prevent damage or preserve glutathione levels during longer occlusions, suggesting a limited protective role.
Area of Science:
- Cardiology
- Biochemistry
- Pharmacology
Background:
- Myocardial infarction is a significant cause of mortality.
- Glutathione plays a crucial role in cellular antioxidant defense.
- The protective effect of exogenous glutathione in ischemia without reperfusion is not well understood.
Purpose of the Study:
- To investigate the efficacy of exogenous glutathione in mitigating myocardial damage.
- To assess the impact of glutathione on infarct size and myocardial glutathione levels.
- To evaluate the role of endogenous glutathione in myocardial ischemia without reperfusion.
Main Methods:
- Anesthetized dogs underwent permanent coronary ligation for 3 or 6 hours.
- Glutathione was administered intraperitoneally before and during coronary occlusion.
- Hemodynamics, infarct size, myocardial glutathione content, and erythrocyte superoxide dismutase (SOD) activity were measured.
Main Results:
- Saline-treated dogs exhibited myocardial infarction and decreased myocardial glutathione.
- Glutathione treatment slightly reduced infarct size after 3 hours of occlusion but had no effect on glutathione levels or SOD activity.
- Glutathione administration failed to reduce infarct size or prevent glutathione depletion after 6 hours of occlusion.
Conclusions:
- Exogenous glutathione offers minimal benefit for myocardial damage from permanent coronary occlusion.
- Endogenous glutathione appears to have a limited role in protecting the myocardium during ischemia without reperfusion.
Abstract:
The present study was to evaluate the effect of exogenous glutathione on myocardial damage resulting from permanent (no reperfusion) coronary ligation (3 or 6 h) in anaesthetized dogs. Haemodynamics, infarct size and myocardial glutathione content were determined. Erythrocyte superoxide dismutase (SOD) activity was also determined in coronary venous blood samples. Glutathione was administered by the intraperitoneal route, 100 mg kg-1 as initial dose given 5 min before coronary ligation, and successive doses of 25 mg kg-1 every 40 min throughout the study period. Saline-treated dogs showed myocardial infarction, a decrease in myocardial glutathione content, and a transient increase in SOD activity. Three hours occlusion in glutathione-treated dogs resulted in a small reduction of infarct size, and no changes in myocardial glutathione content and SOD activity. By contrast, administration of glutathione failed to reduce infarct size and failed to prevent myocardial glutathione decrease in dogs subjected to 6 h occlusion. These results indicate that exogenous glutathione is of minor beneficial effect for myocardial damage resulting from permanent coronary occlusion and suggest that endogenous glutathione has a limited role in protecting against myocardial ischaemia without reperfusion.