The isolated perfused heart according to langendorff technique function application
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1. Definition. The isolated perfused heart according to Langendorff is a preparation which is easily obtained from all warm-blooded animals. The heart is usually perfused at constant pressure, but frequently at constant flow, mostly with oxygenated saline solutions. The ventricles do not fill with the perfusate and therefore do not perform pressure-volume work. If, however, an intraventricular balloon is inserted, the ventricle can contract isovolumetrically. 2. Measuring parameters. Mechanical parameters of the working myocardium (contractile force, volume, ventricular diameter), mean coronary flow, bioelectrical parameters (EKG, monophasic injury potentials), and cardiac rhythm can be measured and recorded. 3. Function tests. The intact function of the working myocardium and the coronary vessels should be examined using various simple tests regarding the myocardium, the smooth musculature, and the endothelium of coronary vessels. 4. Possible applications. In the Langendorff-heart of normal or pretreated animals, inotropic, chronotropic, antiarrhythmic or vasoactive substances can be investigated in the steady state or by means of specific stress tests. In addition, the preparation is particularly suitable for biochemical studies of myocardial metabolism. 6. Advantages. Due to the technical ease with which a variety of parameters can be measured, a single heart can provide maximum information about the condition of the myocardium and the coronary vessels. Thus, it is not surprising to find that 90 years after its first description, the isolated perfused heart according to Langendorff continues to be utilized.
One of the methods of donor heart protection against ischemia is a substantial lowering of temperature of the heart perfused with cardioplegic solution (CS). The achieved conservation of energetically rich compounds, however, does not guarantee the full restoration of heart function during reperfusion. Another possibility for heart preservation is repeated application of CS at 20 degrees C. This variant was tested in our experiments on isolated rat hearts perfused under constant pressure with the Krebs-Henseleit solution according to Langendorff. During global ischemia (180 min at 20 degrees C) we applied the St. Thomas Hospital CS lx or 4 x at 60 min intervals. During the ischemia, glycogen, ATP, lactate, Na+, K+ were assessed in the heart. The heart injury was monitored as the release of lactate dehydrogenase (LD) during the 60 min reperfusion. Repeated CS perfusion of the heart during ischemia lowers the contents of lactate and maintains ATP and glycogen content at elevated levels throughout ischemia. The improved condition of the heart after repeated CS application demonstrated as prevention of the gain of Na+ in the cells at the end of ischemia as well as after reperfusion. This was associated with reduced intracellular potassium depletion and LD release into the perfusate.
- MeSH
- adenosintrifosfát metabolismus MeSH
- energetický metabolismus * MeSH
- glykogen metabolismus MeSH
- kardioplegické roztoky aplikace a dávkování MeSH
- krysa rodu Rattus MeSH
- kyselina mléčná MeSH
- laktáty metabolismus MeSH
- myokard metabolismus MeSH
- reperfuze myokardu * MeSH
- techniky in vitro MeSH
- transplantace srdce * MeSH
- uchovávání orgánů metody MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- adenosintrifosfát MeSH
- glykogen MeSH
- kardioplegické roztoky MeSH
- kyselina mléčná MeSH
- laktáty MeSH
