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Updated: Jul 29, 2026
06:11
Model of Ischemia and Reperfusion Injury in Rabbits
Published on: November 3, 2023
Reperfusion induces myocardial apoptotic cell death
Z Q Zhao1, M Nakamura, N P Wang
1Department of Surgery, Emory University School of Medicine, Atlanta, GA 30365-2225, USA.
Cardiovascular Research
|March 23, 2000
Summary
Myocardial apoptosis is primarily induced by reperfusion, not permanent ischemia. Reperfusion injury involves Bcl-2 family proteins and polymorphonuclear neutrophil accumulation, contributing to cell death.
Area of Science:
- Cardiovascular Research
- Cellular Biology
- Pathology
Background:
- Ischemia and reperfusion (I/R) injury is a critical factor in cardiovascular diseases.
- Understanding the mechanisms of cell death, including apoptosis, during I/R is crucial for developing therapeutic strategies.
Purpose of the Study:
- To investigate if apoptosis occurs during ischemia (I) and reperfusion (R).
- To determine if I/R-induced apoptosis correlates with changes in Bcl-2 and Bax protein expression.
Main Methods:
- Open-chest dogs underwent either permanent ischemia (PI) or 60 minutes of ischemia followed by 6 hours of reperfusion (I/R).
- Apoptosis was assessed using DNA laddering and the TUNEL assay.
- Bcl-2 and Bax expression levels were analyzed by Western blot.
- Polymorphonuclear neutrophil (PMN) accumulation was quantified via immunohistochemistry and myeloperoxidase activity.
Main Results:
- Permanent ischemia (PI) did not induce significant apoptosis, with minimal TUNEL-positive cells and no DNA laddering.
- Ischemia/reperfusion (I/R) significantly increased TUNEL-positive cells and DNA laddering, indicating apoptosis primarily occurs during reperfusion.
- I/R led to decreased Bcl-2 and increased Bax expression, suggesting the Bcl-2 family's involvement.
- PMN accumulation was significantly higher in the I/R group and correlated with the number of apoptotic cells.
Conclusions:
- Apoptosis, alongside necrosis, is a key cell death mechanism following I/R, but not permanent ischemia.
- The Bcl-2 family proteins likely play a role in early reperfusion-induced myocardial apoptosis.
- Polymorphonuclear neutrophil infiltration may contribute to the development of apoptosis during I/R injury.
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