CAJ | 학술논문

目的观察X射线照射对大鼠心肌线粒体功能的影响以及自噬在线粒体功能损伤中的作用.方法将135只实验大鼠分成假照射组(10只)、照射组(80只)和照射+3-甲基腺嘌呤(3-MA)组(45只),假照射组接受0Gy X射线照射,照射组给予20 Gy X射线照射,照射+3-MA组接受20 Gy X射线照射前30 min腹腔注射2μl 3-MA.采用蛋白免疫印迹法和实时定量PCR法检测心肌细胞的LC3Ⅱ及Beclin 1蛋白表达及其mRNA水平变化,检测左心室舒张压及±dP/dtm(左心室压力上升及下降的最大速率)等离体心功能指标.结果与假照射组相比,照射组大鼠经20 GyX射线照射后离体心功能在21 d时出现降低;而在1d时心肌组织线粒体功能便出现了损伤;同时,心肌细胞自噬水平在3h、6h、12h、1d、2d、4d及7d时出现明显上升,与假照射组之间的差异显著,且在6h达到最高值.与照射组相比,照射+3-MA组大鼠心肌LC3Ⅱ及Beclin 1表达水平明显下降,且心功能出现异常的时间提前至14d.结论 X射线照射损伤大鼠心肌线粒体功能并诱导自噬发生,可能是心肌保护的重要因素.
목적 관찰X사선조사대대서심기선립체공능적영향이급자서재선립체공능손상중적작용.방법 장135지실험대서분성가조사조(10지)、조사조(80지)화조사+3-갑기선표령(3-MA)조(45지),가조사조접수0Gy X사선조사,조사조급여20 Gy X사선조사,조사+3-MA조접수20 Gy X사선조사전30 min복강주사2μl 3-MA.채용단백면역인적법화실시정량PCR법검측심기세포적LC3Ⅱ급Beclin 1단백표체급기mRNA수평변화,검측좌심실서장압급±dP/dtm(좌심실압력상승급하강적최대속솔)등리체심공능지표.결과 여가조사조상비,조사조대서경20 GyX사선조사후리체심공능재21 d시출현강저;이재1d시심기조직선립체공능편출현료손상;동시,심기세포자서수평재3h、6h、12h、1d、2d、4d급7d시출현명현상승,여가조사조지간적차이현저,차재6h체도최고치.여조사조상비,조사+3-MA조대서심기LC3Ⅱ급Beclin 1표체수평명현하강,차심공능출현이상적시간제전지14d.결론 X사선조사손상대서심기선립체공능병유도자서발생,가능시심기보호적중요인소.
Objective To observed the effects of X-ray irradiation on myocardial mitochondrial function and role of autophagy in mitochondrial injury.Methods The rats were divided into shamirradiation control group,irradiation group and irradiation+3-methyladenine (3-MA) group.Rat in shamirradiation control group accepted no irradiation,while rat in irradiation group accepted local 20 Gy X-ray irradiation in the chest,the last group accepted 20 Gy X-ray irradiation prior to intraperitoneal injection 2 μl 3-MA.Western blot and real time PCR were used to detect the expression of LC3 Ⅱ and Beclin 1 in protein and their mRNA levels.In vitro cardiac function was used to detect the changes of the left ventricular diastolic pressure (LVDP),the maximal rate of rise of pressure in the isovolumetric systolic left ventricle (+dP/dt,max)and the maximal rate of rise of pressure in the isovolumetric diastolic left ventricle (-dP/dt.x).Results Compared with the sham-irradiation control group,there were the decreased of the LVDP,+dP/dtmax and-dP/dtmax at 21 d,and myocardial mitochondrial injury at 1 d after 20 Gy irradiation.The expression of LC3 and Beclin 1 in protein and mRNA levels increased significantly at 3 h,6 h,12 h,1 d,2 d,4 d and 7 d after 20 Gy irradiation,up to peak at 6 h.Compared with irradiation group,intraperitoneal injection 2 μl 3-MA 30 min before irradiation,the expression of LC3 Ⅱ and Beclin 1 in protein decreased significantly at 6 h after irradiation,there were the decreased of the LVDP,+dP/dtmax and-dP/dtmax at 14 d,then the irradiation group for 21 days.Conclusion X-ray irradiation could injury myocardial mitochondrial function and induce autophagy in rat myocardial cell,which was an important factor of myocardial protection.