Accumulating evidence has suggested that the gap junction plays an important role in the determination of cerebral ischemia, but the underlying mechanisms remain to be elucidated. In this study, we assessed the effect...Accumulating evidence has suggested that the gap junction plays an important role in the determination of cerebral ischemia, but the underlying mechanisms remain to be elucidated. In this study, we assessed the effect of a gap-junction blocker, carbenoxolone （CBX）, on ischemia/reperfusion-induced brain injury and the possible mechanisms. By using the transient cerebral ischemia model induced by occlusion of the middle cerebral artery for 30 min followed by reperfusion for 24 h, we found that pre-administration of CBX （25 mg/kg, intracerebroventricular injection, 30 min before cerebral ischemic surgery） diminished the infarction size in rats. And this was associated with a decrease of reactive oxygen species generation and inhibition of the activation of astrocytes and microglia. In PC12 cells, H202 treatment induced more coupling and apoptosis, while CBX partly inhibited the opening of gap junctions and improved the cell viability. These results suggest that cerebral ischemia enhances the opening of gap junctions. Blocking the gap junction with CBX may attenuate the brain injury after cerebral ischemia/reperfusion by partially contributing to amelioration of the oxidative stress and apoptosis.展开更多
Radiation-induced bystander effect is the phenomenon that the cells which are not directly exposed to radiation have identical or similar biological reactions with the cells of direct exposure to radiation. It is a co...Radiation-induced bystander effect is the phenomenon that the cells which are not directly exposed to radiation have identical or similar biological reactions with the cells of direct exposure to radiation. It is a common second reaction of radiotherapy and has a strong impact on cancer patients. Here we review and synthesize its studies in vitro and in vivo, its time effect and the mechanism. And the existing problems and its research significance are also discussed.展开更多
基金supported by the National Natural Science Foundation of China (30872731)Natural Science Foundation of Gansu Province, China (2008GS01435 and 1010RJZA114)
文摘Accumulating evidence has suggested that the gap junction plays an important role in the determination of cerebral ischemia, but the underlying mechanisms remain to be elucidated. In this study, we assessed the effect of a gap-junction blocker, carbenoxolone （CBX）, on ischemia/reperfusion-induced brain injury and the possible mechanisms. By using the transient cerebral ischemia model induced by occlusion of the middle cerebral artery for 30 min followed by reperfusion for 24 h, we found that pre-administration of CBX （25 mg/kg, intracerebroventricular injection, 30 min before cerebral ischemic surgery） diminished the infarction size in rats. And this was associated with a decrease of reactive oxygen species generation and inhibition of the activation of astrocytes and microglia. In PC12 cells, H202 treatment induced more coupling and apoptosis, while CBX partly inhibited the opening of gap junctions and improved the cell viability. These results suggest that cerebral ischemia enhances the opening of gap junctions. Blocking the gap junction with CBX may attenuate the brain injury after cerebral ischemia/reperfusion by partially contributing to amelioration of the oxidative stress and apoptosis.
基金the National Natural Science Foundation of China (81460695, 81760836).
文摘Radiation-induced bystander effect is the phenomenon that the cells which are not directly exposed to radiation have identical or similar biological reactions with the cells of direct exposure to radiation. It is a common second reaction of radiotherapy and has a strong impact on cancer patients. Here we review and synthesize its studies in vitro and in vivo, its time effect and the mechanism. And the existing problems and its research significance are also discussed.
