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Updated: Jul 4, 2026
Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury
Published on: March 7, 2022
Inhibiting matrix metalloproteinase-2 reduces protein release into coronary effluent from isolated rat hearts during
Justyna Fert-Bober1, Hernando Leon, Jolanta Sawicka
1Dept. of Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada.
Background:
Previous studies have shown that the disruption of the coronary endothelium and the increase in its permeability during ischemia-reperfusion (I/R), are linked to matrix metalloproteinase-2 (MMP-2) activity. Studies from our group have shown that during I/R, activity of MMP-2 in the coronary effluent increases and this increase is associated with cardiac dysfunction, which in turn, can be prevented by MMP inhibitors. Therefore, we hypothesize that inhibiting MMPs reduces the MMP-2 dependent disruption of the coronary endothelium and subsequent protein release during I/R.
Methods:
Isolated rat hearts were perfused in the Langendorff mode at a constant pressure and subjected to 15, 20 or 30 min no-flow ischemia followed by 30 min of reperfusion. The MMP inhibitors, o-phenanthroline (Phen, 100 microM) or doxycycline (Doxy, 30 microM) an inhibitors of MMPs, were added to the perfusion solution 10 min before ischemia and for the first 10 min of reperfusion. The coronary effluents were collected during perfusion for protein analysis. Creatine kinase was measured as an index of cellular damage. Endothelial integrity was assessed by measuring coronary flow and by measuring the levels of serotransferrin and interstitial albumin in the coronary effluent. Additionally, damage to the endothelium was assessed histologically by light microscopy analysis of the cellular structure of the myocardium. MMP-2 activity was measured by zymography in hearts subjected to 15, 20 and 30 min of ischemia without reperfusion.
Results:
MMP-2 activity was increased in heart tissue at the end of ischemia and was correlated with duration of ischemia. The post-ischemia decrease in coronary flow, and the increase in the release of serotransferrin and albumin were attenuated by Phen. Edema (another indirect marker of endothelial damage) was observed in I/R heart and the edema was abolished in I/R heart treated with MMP inhibitors.
Conclusion:
MMP inhibition not only reduces cardiac mechanical dysfunction but also reduces endothelial damage resulting from cardiac I/R injury.
Insights
Matrix metalloproteinase inhibition reduces cardiac endothelial damage and dysfunction during ischemia-reperfusion injury. This study shows that inhibiting matrix metalloproteinases (MMPs) protects the coronary endothelium from damage and preserves cardiac function following ischemia-reperfusion.
Area of Science:
- Cardiovascular Research
- Biochemistry
- Cell Biology
Background:
- Ischemia-reperfusion (I/R) injury disrupts coronary endothelium and increases permeability, linked to matrix metalloproteinase-2 (MMP-2) activity.
- Elevated MMP-2 activity in coronary effluent during I/R correlates with cardiac dysfunction.
- MMP inhibitors have previously shown potential in preventing I/R-induced cardiac dysfunction.
Purpose of the Study:
- To investigate if MMP inhibition reduces MMP-2 dependent disruption of the coronary endothelium during I/R.
- To assess the impact of MMP inhibitors on endothelial integrity and protein release post-I/R.
- To determine the protective effects of MMP inhibitors against cardiac I/R injury.
Main Methods:
- Isolated rat hearts underwent 15-30 min ischemia followed by 30 min reperfusion.
- Hearts were treated with MMP inhibitors (o-phenanthroline or doxycycline) before and during reperfusion.
- Coronary effluents were analyzed for protein content, and endothelial integrity was assessed via coronary flow, serotransferrin, and albumin levels.
Main Results:
- MMP-2 activity increased with ischemia duration.
- MMP inhibitors attenuated the decrease in coronary flow and reduced serotransferrin and albumin release.
- Edema, an indicator of endothelial damage, was abolished in hearts treated with MMP inhibitors.
Conclusions:
- MMP inhibition effectively reduces endothelial damage caused by cardiac I/R injury.
- Inhibiting MMPs not only mitigates cardiac mechanical dysfunction but also preserves endothelial integrity.
- These findings highlight MMP inhibitors as a potential therapeutic strategy for I/R injury.