Calcium and its role in myocardial cell injury during ischemia and reperfusion.
Direct measurements of intracellular free Ca2+ concentration ([Ca2+]i) were obtained during ischemia and reperfusion in ferret hearts loaded with the Ca2+ indicator, the 5,5'-difluoro derivative of 1,2-bis(o-aminophenoxy)ethane-N,N,N',N',-tetraacetic acid. During 15 minutes of ischemia at 37 degrees C, time-averaged [Ca2+]i increased significantly and decreased rapidly during reperfusion. In contrast to metabolic inhibition in isolated muscle or cells, the increase in [Ca2+]i during true ischemia occurs in the absence of a mechanical contracture. After ischemia, contractile function does not recover completely: the hearts are "stunned." Our results support the hypothesis that an increase in cellular calcium-loading causes dysfunction in the form of myocardial stunning while leaving unresolved the precise mechanism of the calcium-mediated injury.
Marban
E
E
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Koretsune
Y
Y
Corretti
M
M
Chacko
V P
VP
Kusuoka
H
H
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002614:Chelating Agents; D003327:Coronary Disease / Q000378:metabolism*; D004533:Egtazic Acid / Q000031:analogs & derivatives; D005289:Ferrets; D009682:Magnetic Resonance Spectroscopy; D009200:Myocardial Contraction / Q000502:physiology; D015425:Myocardial Reperfusion; D015428:Myocardial Reperfusion Injury / Q000473:pathology*; D009206:Myocardium / Q000378:metabolism*; D013997:Time Factors
D002614:Chelating Agents; D004533:Egtazic Acid; C039877:5,5'-difluoro-1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium