title: Reactive oxygen species and x-ray disrupted spontaneous [Ca²⁺]I oscillation in alveolar macrophages.
abstract: Radiation leads to a rapid burst of reactive oxygen species (ROS), which is considered to be one of the major causes of radiation-induced injury. ROS have previously been shown to induce changes in cytosolic Ca²⁺ ([Ca²⁺]i) including [Ca²⁺]i oscillation. However, the role of radiation in [Ca²⁺]i oscillation is poorly understood. The purpose of this study was to identify the effect of ROS and X ray on [Ca²⁺]i oscillation, as well as their role in radiation-induced lung injury. Alveolar macrophages were cultured in the absence and presence of different doses of hydrogen peroxide (H₂O₂) or exposed to X-ray irradiation with or without pretreatment of diphenyleneiodonium chloride (DPI, an inhibitor of NADPH oxidases) or tetrandrine (TET, a calcium entry blocker) and cytosolic Ca²⁺ concentration was detected by fluorescent Ca²⁺ indicator Fura-2. Rat radiation lung injury was induced in vivo by using 40 Gy X ray and DPI or TET was used to prevent radiation-induced lung injury. The results showed that there was spontaneous [Ca²⁺]i oscillation in alveolar macrophages under normal conditions, and treatment of H₂O₂ (100-500 μM) or 2 Gy X ray inhibited the spontaneous [Ca²⁺]i oscillation and induced [Ca²⁺]i rise. TET abolished H₂O₂ or X ray induced [Ca²⁺]i rise in alveolar macrophages, and attenuated X ray- induced rat alveolitis in vivo. DPI prevented X-ray-induced inhibition of [Ca²⁺]i oscillation in alveolar macrophages and prevented X-ray-induced rat alveolitis. Taken together, the data suggest that the disruption of [Ca²⁺]i oscillation and induction of [Ca²⁺]i rise through ROS is involved in the mechanism of radiation-induced lung injury.
authors: Department of Respiratory Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China.
authors: Hao
authors: H
authors: Chen
authors: Hong
authors: H
authors: Ye
authors: Da-Quan
authors: DQ
authors: Meng
authors: Peng-Cheng
authors: PC
authors: Cai
authors: Feng
authors: F
authors: Chen
authors: Li-Ping
authors: LP
authors: Zhu
authors: Qiu
authors: Q
authors: Tang
authors: Zhi-Xiong
authors: ZX
authors: Long
authors: Qiong
authors: Q
authors: Zhou
authors: Yang
authors: Y
authors: Jin
authors: Jian-Bao
authors: JB
authors: Xin
authors: Xiao-Nan
authors: XN
authors: Tao
authors: Wan-Li
authors: WL
authors: Ma
mesh_terms: D000818:Animals; D044182:Benzylisoquinolines / Q000494:pharmacology; D020013:Calcium Signaling / Q000528:radiation effects*; D002478:Cells, Cultured; D016676:Macrophages, Alveolar / Q000378:metabolism / Q000528:radiation effects*; D008297:Male; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors; D009861:Onium Compounds / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014965:X-Rays
chemical_list: D044182:Benzylisoquinolines; D009861:Onium Compounds; D017382:Reactive Oxygen Species; C009438:tetrandrine; C007517:diphenyleneiodonium; D019255:NADPH Oxidases