Antiarrhythmic effect of tamoxifen on the vulnerability induced by hyperthyroidism to heart ischemia/reperfusion damage.
J Steroid Biochem Mol Biol
; 143: 416-23, 2014 Sep.
Article
en En
| MEDLINE
| ID: mdl-24923730
Hyperthyroidism, known to have deleterious effects on heart function, and is associated with an enhanced metabolic state, implying an increased production of reactive oxygen species. Tamoxifen is a selective antagonist of estrogen receptors. These receptors make the hyperthyroid heart more susceptible to ischemia/reperfusion. Tamoxifen is also well-known as an antioxidant. The aim of the present study was to explore the possible protective effect of tamoxifen on heart function in hyperthyroid rats. Rats were injected daily with 3,5,3'-triiodothyronine at 2mg/kg body weight during 5 days to induce hyperthyroidism. One group was treated with 10mg/kg tamoxifen and another was not. The protective effect of the drug on heart rhythm was analyzed after 5 min of coronary occlusion followed by 5 min reperfusion. In hyperthyroid rats not treated with tamoxifen, ECG tracings showed post-reperfusion arrhythmias, and heart mitochondria isolated from the ventricular free wall lost the ability to accumulate and retain matrix Ca(2+) and to form a high electric gradient. Both of these adverse effects were avoided with tamoxifen treatment. Hyperthyroidism-induced oxidative stress caused inhibition of cis-aconitase and disruption of mitochondrial DNA, effects which were also avoided by tamoxifen treatment. The current results support the idea that tamoxifen inhibits the hypersensitivity of hyperthyroid rat myocardium to reperfusion damage, probably because its antioxidant activity inhibits the mitochondrial permeability transition.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Arritmias Cardíacas
/
Tamoxifeno
/
Daño por Reperfusión Miocárdica
/
Antagonistas de Estrógenos
/
Hipertiroidismo
/
Mitocondrias Cardíacas
Tipo de estudio:
Etiology_studies
Límite:
Animals
Idioma:
En
Revista:
J Steroid Biochem Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Año:
2014
Tipo del documento:
Article
País de afiliación:
México
Pais de publicación:
Reino Unido