Related Experiment Videos
Ischaemic preconditioning limits infarct size in the rat heart
D M Yellon1, A M Alkhulaifi, E E Browne
1Hatter Institute for Cardiovascular Studies, Department of Academic Cardiology, University College and Middlesex Hospital, London, United Kingdom.
Cardiovascular Research
|October 1, 1992
Summary
Rat hearts can be protected from prolonged ischemia through preconditioning. This study found that the protective mechanism does not involve the inhibition of mitochondrial ATPase, suggesting other pathways are involved.
Area of Science:
- Cardiovascular Physiology
- Mitochondrial Function
- Ischemic Heart Disease
Background:
- Ischemic preconditioning (IP) protects the heart against prolonged ischemia.
- A proposed mechanism involves reduced ATP utilization during ischemia, potentially via inhibition of mitochondrial ATPase.
- Rats have lower levels of the inhibitor protein, prompting investigation into their preconditioning capacity.
Purpose of the Study:
- To determine if rat hearts can be subjected to ischemic preconditioning.
- To investigate the role of mitochondrial ATPase inhibition in the protective effects of IP in rats.
Main Methods:
- Anesthetized rats underwent a 5-minute left main coronary artery occlusion followed by 10 minutes of reperfusion (preconditioning).
- Hearts were then subjected to 45 minutes of ischemia and 3 hours of reperfusion.
- Infarct size was quantified and compared to control hearts without preconditioning.
Main Results:
- Ischemic preconditioning significantly reduced infarct size in rat hearts (31.4% vs. 61.0% of risk area).
- The reduction in infarct size was statistically significant (p < 0.005).
Conclusions:
- Rat hearts demonstrate the capacity for ischemic preconditioning.
- The protective mechanism in rat hearts is unlikely to be mediated by endogenous inhibition of mitochondrial ATPase.
- Reduced ATP wastage may not be the sole contributor to the protective effects of ischemic preconditioning.