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Transcardiac alteration of neutrophil function before and after coronary thrombolysis in human myocardial infarction
S Hoshida1, T Kuzuya, M Nishida
1First Department of Medicine, Osaka University School of Medicine, Japan.
Insights
Neutrophil function in the coronary sinus is reduced during heart attack ischemia but recovers after reperfusion therapy. This suggests factors in the coronary circulation affect neutrophil activity during myocardial infarction.
Area of Science:
- Cardiovascular Science
- Immunology
- Hematology
Background:
- Neutrophils play a critical role in myocardial ischemia and reperfusion injury.
- Understanding neutrophil function during coronary artery occlusion is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the functional changes of neutrophils in the coronary sinus before and after thrombolytic reperfusion in patients with occluded coronary arteries.
- To compare neutrophil function in the coronary sinus with systemic circulation (aorta) during ischemia and reperfusion.
Main Methods:
- Isolated neutrophils from the aorta and coronary sinus of 17 patients were analyzed.
- Assessed neutrophil functions included free radical generation (using ferricytochrome c reduction and luminol-enhanced chemiluminescence), aggregation, and chemotaxis.
- Measurements were taken before and after thrombolytic reperfusion in patients with left or right coronary artery disease.
Main Results:
- Before reperfusion in left coronary artery disease, neutrophils in the coronary sinus showed significantly reduced free radical generation (20-30%), aggregation (21%), and chemotaxis (20%) compared to the aorta.
- After reperfusion, neutrophil function in the coronary sinus returned to levels similar to the aorta.
- No significant changes in neutrophil function were observed in right coronary artery disease or in neutrophil counts in either artery.
Conclusions:
- Neutrophil function is significantly altered within the coronary circulation during myocardial ischemia and recovers post-reperfusion.
- These findings suggest the presence of factors within the ischemic coronary bed that modulate neutrophil activity, or a washout of activated neutrophils after reperfusion.
Abstract:
We examined function of isolated neutrophils taken from aorta and coronary sinus before and after thrombolytic reperfusion in 17 patients whose infarct-related coronary arteries were totally occluded. Before reperfusion in left coronary artery disease, free radical generation by activated neutrophils in coronary sinus, assessed by ferricytochrome c reduction (phorbol myristate acetate, 10 ng/ml) and luminol-enhanced chemiluminescence (A23187, 2 microM), was reduced by 20% (P less than 0.05) and 30% (P less than 0.05), respectively, compared with those in aorta. Neutrophil aggregation (A23187, 10 microM) and chemotactic activity (formyl-methionyl-leucyl-phenylalanine, 5 microM) were also reduced in coronary sinus by 21% and 20%. After reperfusion the extent of such neutrophil function in coronary sinus recovered and was similar to that in aorta. There were no significant differences between neutrophil counts in aorta and coronary sinus before and after reperfusion. In right coronary artery disease, no significant changes were seen in these functions of neutrophils of aorta and coronary sinus before and after reperfusion. These results indicate that function of neutrophils passing through coronary circulation fluctuated significantly in association with reperfusion, suggesting (1) factor(s) that depress neutrophil function are produced in coronary circulation during myocardial ischemia and their effects are overcome after reperfusion or (2) activated neutrophils, trapped in the ischemic coronary bed, are washed out to coronary sinus after reperfusion.