CAJ | 학술논문

目的探讨应激性心肌损伤的发病机制.方法 30只雄性Wistar大鼠按随机数字表法分成正常对照组、制动后冰泳应激组(每日制动6h,第13日开始制动后冰泳5 min)、内毒素组[腹腔注射脂多糖(LPS)10 mg/kg]3组,每组10只.取心肌组织,光镜下观察心肌组织病理变化;电镜下观察心肌超微结构;用酶联免疫吸附试验(ELISA)检测血清心肌肌钙蛋白Ⅰ(cTnI)含量;用原位末端缺刻标记法(TUNEL)检测心肌细胞凋亡并计算凋亡指数;用免疫组化法检测心肌组织天冬氨酸特异性半胱氨酸蛋白酶(caspase-8和caspase-3)的表达;并分析caspase与细胞凋亡指数的相关性.结果与正常对照组相比,制动冰泳应激组和内毒素应激组在光镜和电镜下均有不同程度的心肌细胞损伤表现,血清cTnI含量(μg/L)均明显增加(0.63±0.12、0.74±0.08比0.53±0.03,P＜0.05和P＜0.01);心肌细胞凋亡指数有不同程度增加[(7.91±1.71 )％、(12.94±2.00)％比0],心肌组织中caspase-8和caspase-3表达增加(caspase-8灰度值:126.65±3.13、114.82±8.67比156.99±9.66; caspase-3灰度值:130.20±2.96、108.58±5.72比160.51±5.25,均P＜0.01),且内毒素应激组各指标均明显高于制动冰泳应激组(P＜0.05或P＜0.01).相关分析显示,制动冰泳应激组中caspase-8、caspase-3与细胞凋亡指数呈显著正相关(r=0.914,P1=0.002;r2=0.929,P2=0.001);内毒素应激组中caspase-8、caspase-3与细胞凋亡指数呈显著正相关(r1=0.956,P1 =0.000;r2=0.916,P2=0.001).结论应激可能通过增加caspase-8和caspase-3蛋白的表达诱导大鼠心肌细胞凋亡,从而导致心肌损伤.
목적 탐토응격성심기손상적발병궤제.방법 30지웅성Wistar대서안수궤수자표법분성정상대조조、제동후빙영응격조(매일제동6h,제13일개시제동후빙영5 min)、내독소조[복강주사지다당(LPS)10 mg/kg]3조,매조10지.취심기조직,광경하관찰심기조직병리변화;전경하관찰심기초미결구;용매련면역흡부시험(ELISA)검측혈청심기기개단백Ⅰ(cTnI)함량;용원위말단결각표기법(TUNEL)검측심기세포조망병계산조망지수;용면역조화법검측심기조직천동안산특이성반광안산단백매(caspase-8화caspase-3)적표체;병분석caspase여세포조망지수적상관성.결과 여정상대조조상비,제동빙영응격조화내독소응격조재광경화전경하균유불동정도적심기세포손상표현,혈청cTnI함량(μg/L)균명현증가(0.63±0.12、0.74±0.08비0.53±0.03,P＜0.05화P＜0.01);심기세포조망지수유불동정도증가[(7.91±1.71 )％、(12.94±2.00)％비0],심기조직중caspase-8화caspase-3표체증가(caspase-8회도치:126.65±3.13、114.82±8.67비156.99±9.66; caspase-3회도치:130.20±2.96、108.58±5.72비160.51±5.25,균P＜0.01),차내독소응격조각지표균명현고우제동빙영응격조(P＜0.05혹P＜0.01).상관분석현시,제동빙영응격조중caspase-8、caspase-3여세포조망지수정현저정상관(r=0.914,P1=0.002;r2=0.929,P2=0.001);내독소응격조중caspase-8、caspase-3여세포조망지수정현저정상관(r1=0.956,P1 =0.000;r2=0.916,P2=0.001).결론 응격가능통과증가caspase-8화caspase-3단백적표체유도대서심기세포조망,종이도치심기손상.
Objective To investigate the pathogenesis of stress myocardial injury.Methods Thirty Wistar rats were randomly divided into three groups,with 10 rats in each group:normal control group,movement restriction and ice swimming stress group (rat movement was restricted 6 hours per day; beginning from 13th day rats were allowed to swim in ice water for 5 minutes,ice stress group),and endotoxin stress group [intraperitoneal injection of lipopolysaccharide (LPS) 10 mg/kg,LPS group].The myocardial tissue was harvested,the pathological changes in myocardial was observed with light microscopy,and the changes in myocardial ultrastructure were observed with electron microscope.The levels of serum cardiac troponin Ⅰ (cTnI) was determined by enzyme-linked immunosorbent assay (ELISA),apoptosis of myocardial cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL),and the apoptotic index was calculated.The caspase-8 and caspase-3 expression in myocardial tissue were assessed by immunohistochemistry.The correlation between caspase and apoptetic index was analyzed.Results Compared with normal control group,in ice stress group and LPS group,myocardial tissue was found to be injured seriously in different degrees under light microscopy and electron microscopy; the content of cTnI (μg/L)in serum was significantly increased (0.63 ± 0.12,0.74 ± 0.08 vs.0.53 ± 0.03,P＜0.05 and P＜0.01 ) ; apoptosis index of myocardial tissue was significantly increased in different degrees [ (7.91 ± 1.71 )％, ( 12.94 ± 2.00) ％ vs.0 ] ;caspase-8 and caspase-3 expressions in the myocardium were increased (caspase-8 gray scale:126.65 ±3.13,114.82 ± 8.67 vs.156.99 ± 9.66; caspase-3 gray scale:130.20 ± 2.96,108.58 ± 5.72 vs.160.51 ± 5.25,all P＜0.01 ).However,the above indexes in LPS group were significantly higher than those in ice stress group (P＜0.05 or P＜0.01 ).The correlation analysis showed that in ice stress gronp,positive correlation was found between caspase-8,caspase-3 and apoptotic index (r1 =0.914,P1 =0.002; r2=0.929,P2=0.001 ); in LPS group,the positive correlation also exist between caspase-8,caspase-3 and apoptotic index (r1 =0.956,P1 =0.000; r2 =0.916,P2=0.001 ).Conclusion Severe stress may produce stress injury of myocardium via increasing expression of caspase-8 and caspase-3 protein.