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Postconditioning with Lactate-enriched Blood for Cardioprotection in ST-segment Elevation Myocardial Infarction
Published on: May 28, 2019
Second window of preconditioning normalizes palmitate use for oxidation and improves function during low-flow
Raymond K Kudej1, Mathew Fasano, Xin Zhao
1Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ, USA.
Cardiovascular Research
|August 13, 2011
Summary
The second window of preconditioning (SWOP) normalizes long-chain free fatty acid oxidation during ischemia, protecting heart function. This metabolic shift improves mechanical performance despite increased non-oxidative glycolysis.
Area of Science:
- Cardiovascular Physiology
- Metabolic Regulation
- Ischemic Heart Disease
Background:
- Cardioprotection mechanisms often involve altered cellular metabolism.
- Limited understanding exists regarding metabolic changes during ischemic preconditioning and subsequent ischemia.
- The delayed phase of preconditioning, or second window of preconditioning (SWOP), offers potential cardioprotection.
Purpose of the Study:
- To investigate the impact of SWOP on long-chain free fatty acid (LCFA) oxidation during ischemia.
- To evaluate the protective effects of SWOP against myocardial infarction and stunning.
- To examine metabolic alterations in conscious pigs subjected to coronary artery stenosis following preconditioning.
Main Methods:
- Three groups of pigs were studied: control, coronary artery stenosis (CAS), and CAS following SWOP.
- Ischemia was induced via left anterior descending (LAD) stenosis, reducing flow by 40% for 90 minutes.
- LCFA oxidation was measured using (13)C palmitate infusion and in vitro nuclear magnetic resonance (NMR) of myocardial samples.
Main Results:
- CAS reduced subendocardial blood flow and induced transmural reductions in LCFA oxidation, increasing glycolysis.
- SWOP normalized LCFA contribution to oxidative ATP synthesis during stenosis, despite elevated lactate.
- SWOP demonstrated significant protection of contractile function, improving systolic wall thickening.
Conclusions:
- SWOP normalizes LCFA oxidative metabolism during ischemia, enhancing contractile function and mechanical performance.
- Metabolic adaptations during SWOP occur transmurally, even when ischemia is localized to the subendocardium.
- SWOP represents a promising therapeutic strategy for mitigating ischemic heart damage.
