Related Experiment Videos
Relation between ischemic preconditioning and the duration of sustained ischemia
1Department of Histology, College of Medicine, Chung-Ang University, Seoul, Korea.
Journal of Korean Medical Science
|April 1, 1995
Summary
Ischemic preconditioning (IP) limits infarct size and delays ultrastructural changes in rabbit hearts during prolonged global ischemia, though it doesn't improve postischemic function. This cardioprotective effect may involve calcium homeostasis.
Area of Science:
- Cardiology
- Physiology
- Cell Biology
Background:
- Ischemic preconditioning (IP) reduces myocardial damage in rats.
- IP's protective effects are diminished in larger animals with prolonged ischemia.
Purpose of the Study:
- To evaluate IP's cardioprotective efficacy in prolonged global ischemia using isolated rabbit hearts.
- To assess IP's impact on left ventricular function, infarct size, and ultrastructural changes.
Main Methods:
- Rabbit hearts underwent 10-60 minutes of sustained global ischemia (SI) followed by 60 minutes of reperfusion.
- IP was induced via 4 cycles of 5-minute global ischemia and 5-minute reperfusion.
- Evaluated left ventricular function (LVF), extent of infarction (EI), and ultrastructural changes.
Main Results:
- No significant difference in LVF recovery between IP and non-IP (ISCH) hearts.
- Extracellular Ca2+ concentration was lower in ISCH hearts.
- Significant reduction in EI in IP hearts (32%) compared to ISCH hearts (67%) after 60 min SI (p < 0.01).
- Ultrastructural changes were heterogeneous and restricted in IP hearts, unlike homogeneous and irreversible changes in ISCH hearts.
Conclusions:
- IP does not attenuate postischemic dysfunction in prolonged ischemia.
- IP provides an infarct size-limiting effect and delays irreversible ultrastructural changes.
- The cardioprotective effect of IP may be linked to calcium homeostasis.