Metabolic and physiological differences between zero-flow and low-flow myocardial ischemia: effects of L-acetylcarnitine
- 35 Downloads
The metabolic and physiologic differences between low-flow and zero-flow ischemia of varying duration were compared in the isolated perfused rat heart. Hearts subjected to 60 and 90 minutes of zero-flow ischemia recovered less cardiac work than hearts subjected to low-flow ischemia. Low-flow ischemia caused a build-up of both myocardial long-chain acyl coenzyme A and acyl carnitine esters, while zero-flow ischemia produced no change in long-chain acyl carnitine and only a transient increase in long-chain acyl coenzyme A. High energy phosphate depletion was greater in zero-flow ischemia. Perfusion with excess free fatty acids decreased the recovery of cardiac work after low-flow ischemia but had no effect after repeated episodes of zero-flow ischemia. L-Acetylcarnitine improved the recovery of cardiac work after low-flow ischemia in hearts perfused with 0.4 and 1.2 mM palmitate. With zero-flow ischemia, L-acetylcarnitine had no effect on the recovery of cardiac work in hearts perfused with 0.4 mM palmitate and a slight but statistically significant effect with 1.2 mM palmitate. Possible protective mechanisms of L-acetylcarnitine against ischemic damage are discussed.
Key wordscarnitine perfused rat heart long-chain acyl coenzyme A
Unable to display preview. Download preview PDF.
- 2.Adam H (1965) Adenosine-5′-diphosphate and adenosine-5′-monophosphate. In: Methods of Enzymatic Analysis, pp 573–577. Academic Press, (New York)Google Scholar
- 5.Crass MF III, McCaskill ES, Shipp JC (1979) Effect of pressure development on glucose and palmitate metabolism in perfused heart. Am J Physiol 216:1569–1576Google Scholar
- 15.Kosolcharoen P, Nappi J, Peduzzi P, Shug AL, Patel A, Filipek T, Thomsen JH (1981) Improved exercise tolerance after administration of carnitine. Curr Therap Res 30:753–764Google Scholar
- 20.Neely JR, Garber D, McDonough K, Idell-Wenger J (1979) Relationship between ventricular function and intermediates of fatty acid metabolism during myocardial ischemia: Effects of carnitine. In: Ischemia Myocardium and Antianginal Drugs, (New York), pp 225–234. Raven PressGoogle Scholar
- 23.Opie LH (1976) Effects of regional ischemia on metabolism of glucose and fatty acids; relative rates of aerobic and anaerobic energy production during myocardial infarction and comparison with effects of anoxia. Circ Res (Suppl I) 38:152–174Google Scholar
- 31.Tubbs PK, Ramsay RR, Edwards MR (1980) Inhibitors of carnitine transport and metabolism. In: Carnitine Biosynthesis, Metabolism, and Function. Academic Press, New York, pp 207–218Google Scholar