Experimental myocardial ischemia. Differential injury of mitochondrial subpopulations.
Distinct populations of subsarcolemmal (SS) and inter-fibrillar (IF) rat cardiac mitochondria were studied following 15 and 30 minutes of warm and cold global ischemia. The respiratory control index, state 3, state 4, adenosine diphosphate-oxygen ratio, and specific enzyme activities of these mitochondrial populations were examined. The subsarcolemmar and IF mitochondria were both severely uncoupled and inhibited by warm ischemia. However, IF mitochondria had a higher RCI at each ischemic interval. In cold ischemia, IF mitochondria were not injured compared with control specimens. Subsarcolemmar mitochondria showed a trend towards a lower RCI that was statistically significant at 30 minutes with succinate as a substrate. These data implicate a differential injury of ischemia on the compartmentalized bioenergy metabolism of the myocardial cell.
Weinstein
E S
ES
Benson
D W
DW
Ratcliffe
D J
DJ
Maksem
J
J
Fry
D E
DE
D000818:Animals; D003080:Cold Temperature; D003327:Coronary Disease / Q000378:metabolism* / Q000473:pathology; D003402:Creatine Kinase / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D004734:Energy Metabolism; D005260:Female; D006358:Hot Temperature; D066298:In Vitro Techniques; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D008929:Mitochondria, Heart / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D010101:Oxygen Consumption; D051381:Rats; D011919:Rats, Inbred Strains
D007521:Isocitrate Dehydrogenase; D003576:Electron Transport Complex IV; D003402:Creatine Kinase