reperfusion

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preconditioning on cardiomyocyte protection against ischemic- ... 2012, IP: 115.248.99.82] || Click here to download free Android application for this journal ...
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Research Article

Evaluation of thyroid hormone induced pharmacological preconditioning on cardiomyocyte protection against ischemicreperfusion injury Anil Kumar, Rajeev Taliyan, P.L. Sharma

ABSTRACT Objectives: Ischemic preconditioning (IPC) has been demonstrated to make myocardium transiently more resistant to deleterious effect of prolonged ischemia. The opening of the mitochondrial permeability transition pore (mPTP) at the time of myocardial reperfusion is a critical determinant of cell death. L-thyroxine pre-treatment increases the tolerance of the heart to ischemia and produces cardioprotection similar to ischemic precondition. This study has been designed to investigate the mechanism involved in L-thyroxine-induced cardiomyocyte protection against ischemia-reperfusion (I/R) injury in rats. Materials and Methods: L-thyroxine (T4) was administered to Wistar rats (n=6) (25 µg/100 g/day s.c.) for two weeks. Hearts from normal and L-thyroxine-treated rats were perfused in Langendorff’s mode and subjected to 30 min of ischemia followed by 120 min of reperfusion. Myocardial infarct size was estimated by triphenyltetrazolium chloride (TTC) staining and lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) was analyzed in coronary effluent. Results: IPC and pharmacological preconditioning (PPC) significantly decreased (P