摘要
目的 探讨Ca2 + 在严重烧伤早期心肌线粒体呼吸功能损害中的作用及其机制。方法 复制 30 %TBSAⅢ度烧伤大鼠模型 ,取正常及伤后 1、3、6、12、2 4h大鼠心肌分离线粒体 ,测其Ca2 + 浓度 ( [Ca2 + ]m)、线粒体PLA2 (mtPLA2 )、一氧化氮合酶 (mtNOS)、F0 F1 ATPase和细胞色素c氧化酶活性 ,同时观察心肌线粒体呼吸功能变化。结果 ①伤后 1h [Ca2 + ]m与线粒体呼吸控制率(RCR)均明显升高 ,且RCR与 [Ca2 + ]m呈显著正相关 ;伤后 3、6、12、2 4h心肌 [Ca2 + ]m、mtPLA2 及mtNOS活性均显著高于正常组 ,但线粒体呼吸功能反而下降 ,RCR与 [Ca2 + ]m呈明显负相关 ,mtNOS、mtPLA2 活性与 [Ca2 + ]m呈明显正相关。②伤后 1h线粒体F0 F1 ATPase合成活性明显升高 ,但 3、6、12、2 4h其合成活性与细胞色素c氧化酶活性均显著低于正常组 ;F0 F1 ATPase水解活性除伤后 3h显著升高外 ,其余各时相点均明显低于正常对照组。结论 [Ca2 + ]m改变是烧伤后心肌线粒体呼吸功能变化的重要原因 ,烧伤初始 [Ca2 + ]m适度升高 ,促进线粒体呼吸功能加强 ;烧伤后续阶段Ca2 + 严重超载激活mtPLA2 。
Objective To explore the role of Ca 2+ in the damage of myocardial mitochondrial respiratory function in the early stage after severe burns. Methods An experimental model of 30%TBSA full thickness skin scalding was established in rats. Myocardial mitochondira were isolated from control rats and burned rats at the 1, 3, 6, 12 and 24 h postburn. Changes of mitochondrial respiratory function were observed, Contents of mitochondrial calcium([Ca 2+ ]m),activities of mtPLA 2 , mtNOS, F 0 F 1 ATPase, and cytochrome coxidase were determined. Results ① At 1 h postburn, [Ca 2+ ]m and mitochondrial respiratory control rate (RCR) were both elevated significantly, and RCR was postively correlated with [Ca 2+ ]m. At 3, 6, 12, and 24 h postburn, [Ca 2+ ]m and the activities of mtNOS and mtPLA 2 were significantly higher than those of the controls, but the mitochondrial respiratory function of burned rats decreased, and RCR was negatively correlated with [Ca 2+ ]m, while mtNOS and mtPLA 2 activities were both positively correlated with [Ca 2+ ]m. ②The F 0 F 1 ATPase synthetic activity increased at the 1st hour postburn, but it and the cytochrome coxidase activity both decreased at 3, 6, 12 and 24 h postburn. Except for elevation at 3 h postburn, the F 0 F 1 ATPase hydrolytic activity decreased at all other time points. Conclusions The changes of [Ca 2+ ]m were involved in the damage or regulation of mitochondrial respiratory function after severe burns. Appropriate increase of [Ca 2+ ]m reinforced the mitochondrial respiration fumctionin the beginning statge after severe burns, but activation of mtPLA 2 and mtNOS by severe overloading of Ca 2+ might play an important role in the damages of myocardial mitochondria respiratory function in the following stage after severe burns.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2002年第2期135-137,共3页
Journal of Third Military Medical University
基金
国家重点基础研究发展规划项目 ("973"项目 ) (G19990 54 2 0 2 )
关键词
烧伤
线粒体
钙
心肌
burns
mitochondria
Ca 2+
myocardium
