Related Experiment Video
Updated: Jun 19, 2026
Model of Ischemia and Reperfusion Injury in Rabbits
Published on: November 3, 2023
[Effect of morphine postconditioning on myocardial ischemia-reperfusion injury in rabbits]
Zi-Xi Gong1, Ke Ran, Ye-Tian Chang
1Department of Anesthesiology, The Second Xiangya Hospital, Central South University, Changsha 410011, China.
Objective:
To investigate the protective effects of morphine postconditioning on myocardial ischemia-reperfusion (I/R)injury and the potential mechanisms in rabbits.
Methods:
Thirty-two New Zealand male white rabbits were randomly assigned into 4 groups: Group 1 (Sham), Group 2 (I/R), Group 3 (ischemic postconditioning), Group 4 (ischemia and morphine postconditioning). Group 1 was perfused for 160 min; Group 2 underwent 40 min ischemia and 120 min reperfusion; Group 3 underwent three cycles of 30 s reperfusion and 30 s left anterior descending coronary artery re-occlusion immediately after 40 min ischemia and before 120 min reperfusion; Group 4 was given morphine 1.0 mg/kg immediately after 40 min ischemia in 1 min and before 120 min reperfusion. Blood samples were taken from arterial line at 20 min before occlusion, 20 min after occlusion, 40 min after occlusion, 1 h after reperfusion and 2 h after reperfusion for determination of the plasma levels of cardiac troponin I (cTnI). At the end of the reperfusion, infarct size (IS) and area at risk were defined by Evans and TTC staining. Plasma SOD activity and MDA were determined at the end of reperfusion.
Result:
The levels of cTnI were significantly lower during reperfusion in the two postconditioning groups than those in I/R group. The plasma MDA content was significantly lower and SOD activity was significantly higher in the two postconditioning groups than those in I/R group, but there was no difference between two postconditioning groups. Morphine significantly reduced infarct size of the left ventricular area at risk as compared with I/R group (P<0.05).
Conclusion:
Morphine postconditioning is as effective as ischemic postconditioning in the protection of myocardium against I/R injury in rabbits. Decrease in oxygen free radicals and increased antioxidant activity might be involved in its mechanism.
Insights
Morphine postconditioning effectively protects rabbit hearts from ischemia-reperfusion injury, matching ischemic postconditioning's benefits. This protection involves reducing free radicals and enhancing antioxidant activity.
Area of Science:
- Cardiovascular Research
- Pharmacology
- Cellular Biology
Context:
- Myocardial ischemia-reperfusion (I/R) injury is a significant clinical concern.
- Investigating novel therapeutic strategies to mitigate I/R damage is crucial.
- Postconditioning has emerged as a promising protective intervention.
Purpose:
- To evaluate the cardioprotective efficacy of morphine postconditioning against I/R injury in a rabbit model.
- To elucidate the underlying mechanisms, including the role of oxidative stress and antioxidant defense.
Summary:
- Rabbits subjected to 40 minutes of ischemia and 120 minutes of reperfusion were assigned to sham, I/R, ischemic postconditioning, or morphine postconditioning groups.
- Morphine postconditioning (1.0 mg/kg) significantly reduced cardiac troponin I levels, infarct size, and malondialdehyde (MDA) content, while increasing superoxide dismutase (SOD) activity.
- These effects were comparable to those observed with traditional ischemic postconditioning.
Impact:
- Morphine postconditioning demonstrates significant cardioprotection against I/R injury, comparable to ischemic postconditioning.
- The protective effects are associated with reduced oxidative stress and enhanced endogenous antioxidant capacity.
- This study suggests a potential therapeutic role for morphine in managing myocardial I/R injury.
