The infarct size-limiting effect of ischemic postconditioning (IPOC) is suppressed in isolated hyperhomocysteinemic (Hhcy) rat hearts: The reasonable role of PKC-δ - 26/11/09
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Abstract |
Background |
Recently we have demonstrated that the cardioprotective potential of ischemic postconditioning (IPOC) against ischemia and reperfusion (I/R)-induced myocardial injury was markedly suppressed in hyperhomocysteinemic (Hhcy) rat hearts. The present study investigated the possible role of PKC-δ in Hhcy-induced suppression of myocardial infarct size-limiting effect of IPOC.
Methods |
Isolated Langendorff’s perfused normal and Hhcy rat hearts were subjected to 30-min global ischemia (I), followed by 120-min reperfusion (R). The myocardial damage was assessed by measuring the infarct size, and analyzing the release of LDH and CK-MB in coronary effluent. The oxidative stress in the heart was assessed by measuring lipid peroxidation and superoxide anion generation.
Results |
The I/R produced myocardial injury in normal and Hhcy rat hearts by increasing myocardial infarct size, LDH and CK in coronary effluent and oxidative stress. Hhcy rat hearts exhibited enhanced I/R-induced myocardial injury and high oxidative stress as compared to normal rat hearts subjected to I/R. The IPOC (six brief episodes of I/R, 10s each) afforded cardioprotection against I/R-induced myocardial injury in normal rat hearts; but IPOC-mediated cardioprotection was abolished in Hhcy rat hearts. Treatment with rottlerin (10μM), a selective inhibitor of PKC-δ, did not affect the cardioprotective effect of IPOC in normal rat hearts; but its treatment significantly restored the myocardial infarct size-limiting effect of IPOC in Hhcy rat hearts.
Conclusion |
The high oxidative stress produced in Hhcy rat hearts during reperfusion may activate PKC-δ, which may be responsible for impairing the infarct size-limiting potential of IPOC in Hhcy rat hearts.
Le texte complet de cet article est disponible en PDF.Keywords : Postconditioning, Ischemia–reperfusion injury, Hyperhomocysteinemia, Protein kinase C-delta
Plan
Vol 63 - N° 10
P. 787-791 - décembre 2009 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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