RESUMEN
Background Medium-dose (25 gray) x-ray radiation therapy has recently been performed on patients with refractory ventricular tachyarrhythmias. Unlike x-ray, carbon ion and proton beam radiation can deliver most of their energy to the target tissues. This study investigated the electrophysiological and pathological changes caused by medium-dose carbon ion and proton beam radiation in the left ventricle (LV). Methods and Results External beam radiation in the whole LV was performed in 32 rabbits. A total of 9 rabbits were not irradiated (control). At the 3-month or 6-month follow-up, the animals underwent an open-chest electrophysiological study and were euthanized for histological analyses. No acute death occurred. Significant LV dysfunction was not seen. The surface ECG revealed a significant reduction in the P and QRS wave voltages in the radiation groups. The electrophysiological study showed that the local conduction times in each LV site were significantly longer and that the local LV bipolar voltages were significantly lower in the radiation groups than in the control rabbits. Histologically, apoptosis, fibrotic changes, and a decrease in the expression of the connexin 43 protein were seen in the LV myocardium. These changes were obvious at 3 months, and the effects were sustained 6 months after radiation. No histological changes were seen in the coronary artery and esophagus, but partial radiation pneumonitis was observed. Conclusions Medium-dose carbon ion and proton beam radiation in the whole LV resulted in a significant electrophysiological disturbance and pathological changes in the myocardium. Radiation of the arrhythmogenic substrate would modify the electrical status and potentially induce the antiarrhythmic effect.
Asunto(s)
Técnicas Electrofisiológicas Cardíacas , Ventrículos Cardíacos , Radioterapia de Iones Pesados , Miocardio , Traumatismos Experimentales por Radiación , Taquicardia Ventricular , Función Ventricular Izquierda , Animales , Conejos , Relación Dosis-Respuesta en la Radiación , Técnicas Electrofisiológicas Cardíacas/métodos , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Ventrículos Cardíacos/efectos de la radiación , Radioterapia de Iones Pesados/métodos , Miocardio/patología , Terapia de Protones/métodos , Traumatismos Experimentales por Radiación/diagnóstico , Traumatismos Experimentales por Radiación/fisiopatología , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatología , Taquicardia Ventricular/radioterapia , Tomografía Computarizada por Rayos X , Función Ventricular Izquierda/efectos de la radiaciónRESUMEN
Sakura-cha (salted cherry blossom tea) is a Japanese tea that is traditionally served at celebrations such as wedding ceremonies. The production of Sakura-cha includes the immersion of cherry blossom flowers in Japanese plum vinegar, and through this process, the byproduct (plum vinegar extract of cherry blossom) is obtained. In this study, the antioxidant activity of the plum vinegar extract of cherry blossom was examined. The plum vinegar extract of cherry blossom had a greater superoxide anion scavenging activity compared with red wine, which is a well-known strong antioxidant. Liquid chromatography-mass spectrometry analysis showed that cyanidin-3-glucoside, cyanidin-3-rutinoside, and caffeic acid were the major components in the phenolic extract prepared from plum vinegar extract of cherry blossom, and they possessed superoxide anion scavenging activity. Caffeic acid is mainly responsible for the scavenging activity of phenolic extract; the contributions of cyanidin-3-glucoside and cyanidin-3-rutinoside were minor.