RESUMEN
BACKGROUND: Induction of heat-shock proteins (HSPs) results in cardioprotection against ischemic insult. Geranylgeranylacetone (GGA), known as an antiulcer agent, reportedly induces HSP72 in the gastric mucosa and small intestine of rats. The present study tested the hypothesis that oral GGA would induce HSP72 in the heart and thus render cardioprotection against ischemia/reperfusion injury in rats. METHODS AND RESULTS: Cardiac expression of HSPs was quantitatively evaluated in rats by Western blot analysis. Ten minutes of whole-body hyperthermia induced HSP72 expression in the rat hearts. A single oral dose of GGA (200 mg/kg) also induced expression of HSP72, which peaked at 24 hours after administration. Therefore, isolated perfused heart experiments using a Langendorff apparatus were performed 24 hours after administration of 200 mg/kg GGA (GGA group) or vehicle (control group). After a 5-minute stabilization period, no-flow global ischemia was given for 20, 40, or 60 minutes, followed by 30 minutes of reperfusion. During reperfusion, the functional recovery was greater and the released creatine kinase was less in the GGA group than in the control group. Electron microscopy findings revealed that the ischemia/reperfusion-induced damage of myocardial cells was prevented in GGA-treated myocytes. CONCLUSIONS: The results suggest that oral GGA is cardioprotective against ischemic insult through its induction of HSP72.
Asunto(s)
Diterpenos/administración & dosificación , Proteínas de Choque Térmico/metabolismo , Daño por Reperfusión Miocárdica/prevención & control , Miocardio/metabolismo , Administración Oral , Animales , Western Blotting , Chaperonina 60/metabolismo , Creatina Quinasa/metabolismo , Relación Dosis-Respuesta a Droga , Proteínas de Choque Térmico HSP27 , Proteínas del Choque Térmico HSP72 , Hemodinámica , Hipertermia Inducida , Técnicas In Vitro , Masculino , Isquemia Miocárdica/metabolismo , Reperfusión Miocárdica , Miocardio/ultraestructura , Proteínas de Neoplasias/metabolismo , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo I , Óxido Nítrico Sintasa de Tipo II , Óxido Nítrico Sintasa de Tipo III , Ratas , Ratas Sprague-Dawley , Recuperación de la Función/efectos de los fármacos , Tiorredoxinas/metabolismoRESUMEN
We report the case of a 54-year-old woman with idiopathic VT originating in the left ventricular outflow tract. She initially presented with palpitations and light-headedness. The morphology of the PVCs exhibited an inferior axis and tall R waves were noted in all the precordial leads. Spontaneous PVCs were transiently terminated by an intravenous injection of adenosine triphosphate. Radiofrequency catheter ablation from the left sinus of Valsalva successfully abolished the PVCs and the VT.