Effects of duration of ischaemia during preconditioning on mechanical function, enzyme release and energy production in the isolated working rat heart.
Repeated brief episodes of ischaemia "precondition" the myocardium and protect it during a subsequent period of sustained ischaemia. We subjected isolated rat hearts to sustained ischaemia with or without reperfusion after different schedules of preconditioning. We demonstrated that preconditioning with three 5 min periods of ischaemia separated by 10 min periods of reperfusion permits better functional recovery than preconditioning with three 2 min ischaemic periods separated by 10 min of reperfusion. Preconditioned hearts had creatine phosphate and adenine nucleotide levels comparable to those in the aerobically perfused controls, and showed good functional recovery. Although the mechanisms by which preconditioning protects the heart from subsequent ischaemic damage are unclear, we speculate that preservation of mitochondrial function and oxidative energy production is involved.
Volovsek
A
A
Department of Pathology and Laboratory Medicine, Middleton Memorial Veterans Hospital, Wisconsin.
Subramanian
R
R
Reboussin
D
D
D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D003402:Creatine Kinase / Q000378:metabolism; D004734:Energy Metabolism; D006003:Glycogen / Q000378:metabolism; D006321:Heart / Q000503:physiopathology; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008297:Male; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000378:metabolism / Q000503:physiopathology*; D015428:Myocardial Reperfusion Injury / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D009206:Myocardium / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D000227:Adenine Nucleotides; D007773:Lactates; D010725:Phosphocreatine; D019344:Lactic Acid; D006003:Glycogen; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase