title: Association of pre-ischaemic disturbances in energy metabolism with postischaemic dysfunction of the rat isolated working heart.
abstract: 1. Metabolic and functional effects of two protocols of preconditioning were compared in rat isolated hearts subjected to 20 min global ischaemia (37 degrees C) and reperfusion (30 min Langendorff + 15 min working). Prior to the ischaemic period, hearts were perfused according to Langendorff (control group) or were preconditioned by three 5 min cycles or two 10 min cycles of ischaemia and reperfusion (PC-I and PC-II groups, respectively). 2. There was no difference in the contractile function between the two preconditioned groups at the onset of sustained ischaemia, although the PC-II group showed enhanced release of adenosine (Ado), inosine, hypoxanthine and xanthine into the interstitium accompanied by losses of tissue adenine nucleotides (sigmaAN = ATP + ADP + AMP), total creatine (sigmaCr = phosphocreatine + creatine) and activation of glycolysis following the preconditioning period. During reperfusion, the PC-I group showed enhanced functional recovery, higher contents of sigmaAN and sigmaCr, and the smallest lactate dehydrogenase release compared with these indices in the control and PC-II groups. Postischaemic myocardial dysfunction was similar in the control and PC-II groups. 3. Functional recovery of hearts in both preconditioned groups was positively correlated with myocardial contents of ATP, sigmaAN and sigmaCr at the end of reperfusion, but not with pre-ischaemic Ado release into the interstitium. The results suggest that pre-ischaemic disturbances of energy metabolism, rather than activation of Ado receptors or stunning, may contribute to efficacy of multiple preconditioning in the rat isolated heart.
authors.affiliation: Institute of Experimental Cardiology, Cardiology Research Centre, Moscow, Russia. Internetcsc@adonis.ias.msk.su
authors.forename: O I
authors.initials: OI
authors.lastname: Pisarenko
authors.forename: V L
authors.initials: VL
authors.lastname: Lakomkin
authors.forename: I M
authors.initials: IM
authors.lastname: Studneva
authors.forename: O V
authors.initials: OV
authors.lastname: Korchazhkina
authors.forename: A I
authors.initials: AI
authors.lastname: Kuzmin
authors.forename: V I
authors.initials: VI
authors.lastname: Kapelko
mesh_terms: D000818:Animals; D004734:Energy Metabolism; D005110:Extracellular Space; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial / Q000009:adverse effects; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D008991:Monitoring, Physiologic; D017202:Myocardial Ischemia / Q000201:enzymology / Q000378:metabolism* / Q000503:physiopathology*; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar
chemical_list: D007770:L-Lactate Dehydrogenase