How does dronedarone affect thyroid hormone signaling in the heart?
['Administration of debutyl-dronedarone (DBD), a TRα1 antagonist abolished the T3-limiting effect on reperfusion injury:', 'Dron affected TR expression in the RA similarly by decreasing TRalpha 1 and beta 1 expression by about 50%.', 'In the LVW, AM and Dron decreased TRbeta 1', 'Hypothyroid heart displays a phenotype of cardioprotection against ischemia and this study investigated whether administration of dronedarone, an amiodarone-like compound that has been shown to preferentially antagonize thyroid hormone binding to thyroid hormone receptor alpha1 (TRalpha1),', 'dronedarone treatment results in cardioprotection by selectively mimicking hypothyroidism.', 'The in vitro and in vivo findings suggest that dronedarone via its metabolite debutyldronedarone acts as a TRalpha(1)-selective inhibitor.', 'Amiodarone resulted in increased T4, T4/T3 and rT3, whereas dronedarone did not alter the thyroid hormone profile in normal animals.']
['Dronedarone via its metabolite debutyldronedarone acts as a TRalpha(1)-selective inhibitor and selectively mimicks hypothyroidism.\nDronedarone  decreases TRalpha 1 and beta 1 expression by about 50%  in the right atrium (RA)  while in the left ventricle, only TRbeta1 is found to be decreased.']
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