内毒素对大鼠心肌肌质网功能的抑制作用  

Inhibition of endotoxin on the function of cardiac sarcoplasmic reticulum in rats

作　　者：陈怀生 刘雪燕 郭晓静 洪澄英 李威 曹静 Chen Huai-Sheng;Liu Xue-Yan;Guo Xiao-Jing;Hong Cheng-Ying;Li Wei;Cao Jing(Department of Intensive Care Unit,the First Affiliated Hospital of Southern University of Science and Technology/the Second Clinical Medical College of Jinan University/Shenzhen Peoples’Hospital,Shenzhen,Guangdong 518020,China;Department of Pathology,the First Affiliated Hospital of Southern University of Science and Technology/the Second Clinical Medical College of Jinan University/Shenzhen Peoples’Hospital,Shenzhen,Guangdong 518020,China)

机构地区：[1]南方科技大学第一附属医院/暨南大学第二临床医学院/深圳市人民医院重症医学科,广东深圳518020 [2]南方科技大学第一附属医院/暨南大学第二临床医学院/深圳市人民医院病理科,广东深圳518020

出　　处：《解放军医学杂志》2020年第7期697-701,共5页Medical Journal of Chinese People's Liberation Army

基　　金：深圳市科创委项目(JCYJ20140416122811971)。

摘　　要：目的观察内毒素致大鼠心肌肌质网相关酶学变化,评价内毒素对大鼠心肌肌质网功能的抑制作用。方法雄性SD大鼠10只,随机均分为空白对照组与内毒素注射组。内毒素注射组构建脓毒症大鼠模型,即从大鼠尾静脉注射脂多糖(0.7 mg/kg),1次/d,共2 d。检测两组大鼠血流动力学参数,评价心肌组织的病理形态学变化,测定心室肌细胞肌质网钙调节蛋白mRNA的表达水平。结果与空白对照组比较,内毒素注射组大鼠心率增快[首日(204±18)次/min vs.(139±10)次/min,次日(199±22)次/min vs.(143±17)次/min,P<0.05],首日平均动脉压(MAP)降低[(87±12)mmHg vs.(102±7)mmHg,P<0.05]。光学显微镜及电子显微镜下可见,内毒素注射组大鼠心肌细胞排列疏松,细胞间炎性细胞浸润,肌纤维断裂,线粒体、肌质网形态辨认困难。反转录实时定量PCR(PT-qPCR)结果显示,注射内毒素后大鼠心室肌肌钙集蛋白(CASQ1)、钠-钙交换体(NCX)、钙调蛋白磷酸酶1(ppplCa)、受磷蛋白(PLN)、肌质网Ca^2+-ATP酶(SERCA2)mRNA表达水平均明显增加(P<0.05)。结论内毒素可通过多种机制影响肌质网钙调节蛋白的作用,抑制心肌细胞功能。Objective To observe the enzymatic changes of myocardial sarcoplasmic reticulum in rats after injecting endotoxin(LPS),and provide basic research results for the future study of myocardial sarcoplasmic reticulum dysfunction caused by LPS in rats.Methods Ten SD rats were randomly divided into blank control group and LPS injection group with 5 rats in each group.In the LPS injection group,endotoxin was injected into the tail vessels of the rats.Results The heart rate(HR)of the LPS injection group increased and was faster than that in the blank control group[(204±18)beat per min vs.(139±10)beat per min on the first day,and(199±22)beat per min vs.(143±17)beat per min on the next day,both P values were less than 0.05].The mean arterial pressure(MAP)was lower than that of the blank control group on the first day[(87±12)mmHg vs.(102±7)mmHg,P<0.05].Under light and electron microscope,the myocardial cells of rats with LPS injection were loosely arranged,with intercellular infiltration with inflammatory cells,muscle fibers broken,and difficult to identify the morphology of mitochondria and sarcoplasmic reticulum.Quantitative PCR results showed that after endotoxin injection,troponin(CASQ1),sodium-calcium exchanger(NCX),calmodulin phosphatase 1(ppplCa),phospholipid protein(PLN),sarcoplasmic reticulum Ca^2+-ATPase(SERCA2)increased significantly(P<0.05).Conclusion Endotoxin can inhibit cardiomyocyte function by affecting the activity of sarcoplasmic reticulum calcium regulatory protein-related enzymes through various mechanisms.

关 键 词：内毒素 心肌细胞 肌质网Ca^2+-ATP酶 肌钙集蛋白 钠-钙交换体 

分 类 号：Q71[生物学—分子生物学]