CAJ | 학술논문

目的评价糖尿病大鼠心肌缺血再灌注时线粒体动力相关蛋白1(Drp1)表达的变化.方法清洁级健康雄性SD大鼠60只,2～3月龄,体重220～ 250 g,采用随机数字表法分为4组(n=15):假手术组(S组)、心肌缺血再灌注组(Ⅰ/R组)、糖尿病+假手术组(DS组)和糖尿病+心肌缺血再灌注组(DI/R组).DS组和DI/R组以高脂高糖饲料喂养和腹腔注射链脲佐菌素的方法制备糖尿病模型.Ⅰ/R组和DI/R组采用结扎冠状动脉左前降支30 min再灌注120 min的方法制备大鼠心肌缺血再灌注损伤模型.于再灌注120 min时处死大鼠,取心肌组织,测定心肌梗死范围,光镜下观察病理学结果;电镜下观察心肌细胞线粒体超微结构;采用TUNEL法检测心肌细胞凋亡情况;采用黄嘌呤氧化酶法和硫代巴比妥酸显色法分别测定超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量;采用免疫组化法和RT-PCR法分别测定心肌Drp1及其mRNA的表达.结果与S组比较,Ⅰ/R组、DS组和DI/R组MDA含量升高,SOD活性降低,Drp1及其mRNA的表达上调,细胞凋亡指数升高(P＜0.05);与Ⅰ/R组比较,DI/R组心肌MDA含量升高,SOD活性降低,Drp1及其mRNA的表达上调,细胞凋亡指数升高,心肌梗死范围增大(P＜0.05);与DS组比较,DI/R组心肌MDA含量升高,SOD活性降低,Drp1及其mRNA表达上调,细胞凋亡指数升高,心肌梗死范围增大(P＜0.05).DI/R组心肌病理学损伤较Ⅰ/R组加重.结论糖尿病大鼠心肌缺血再灌注损伤加重的机制可能与心肌Drp1表达上调有关.
목적 평개당뇨병대서심기결혈재관주시선립체동력상관단백1(Drp1)표체적변화.방법 청길급건강웅성SD대서60지,2～3월령,체중220～ 250 g,채용수궤수자표법분위4조(n=15):가수술조(S조)、심기결혈재관주조(Ⅰ/R조)、당뇨병+가수술조(DS조)화당뇨병+심기결혈재관주조(DI/R조).DS조화DI/R조이고지고당사료위양화복강주사련뇨좌균소적방법제비당뇨병모형.Ⅰ/R조화DI/R조채용결찰관상동맥좌전강지30 min재관주120 min적방법제비대서심기결혈재관주손상모형.우재관주120 min시처사대서,취심기조직,측정심기경사범위,광경하관찰병이학결과;전경하관찰심기세포선립체초미결구;채용TUNEL법검측심기세포조망정황;채용황표령양화매법화류대파비타산현색법분별측정초양화물기화매(SOD)활성화병이철(MDA)함량;채용면역조화법화RT-PCR법분별측정심기Drp1급기mRNA적표체.결과 여S조비교,Ⅰ/R조、DS조화DI/R조MDA함량승고,SOD활성강저,Drp1급기mRNA적표체상조,세포조망지수승고(P＜0.05);여Ⅰ/R조비교,DI/R조심기MDA함량승고,SOD활성강저,Drp1급기mRNA적표체상조,세포조망지수승고,심기경사범위증대(P＜0.05);여DS조비교,DI/R조심기MDA함량승고,SOD활성강저,Drp1급기mRNA표체상조,세포조망지수승고,심기경사범위증대(P＜0.05).DI/R조심기병이학손상교Ⅰ/R조가중.결론 당뇨병대서심기결혈재관주손상가중적궤제가능여심기Drp1표체상조유관.
Objective To evaluate the changes in the expression of mitochondrial fission protein dynamin-related protein-1 (Drp!) during myocardial ischemia-reperfusion (Ⅰ/R) injury in diabetic rats.Methods Sixty healthy adult male Sprague-Dawley rats, weighing 220-250 g, were randomly divided into 4 groups (n =15 each) using a random number table: sham operation group (group S), myocardial Ⅰ/R group (group Ⅰ/R), diabetes mellitus (DM) + sham operation group (group DS), and DM + myocardial Ⅰ/R group (group DI/R).DM was induced by high-fat and high-sucrose diet and intraperitoneal streptozotocin in DS and DI/R groups.Myocardial Ⅰ/R was produced by occlusion of the anterior descending branch of left coronary artery for 30 min followed by 120 min reperfusion in Ⅰ/R and DI/R groups.At 120 min of reperfusion, the rats were sacrificed, and myocardial specimens were obtained for measurement of the myocardial infarct size.The myocardial specimens were cut into sections which were stained with haematoxylin and eosin to examine the pathological changes under light microscope.The ultrastructure of mitochondria in cardiomyocytes was observed by electron microscopy.Apoptosis in cardiomyocytes was determined by TUNEL.Apoptosis index (AI) was calculated.The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured by the methods of xanthine oxidase and thiobarbituric acid, respectively.The expression of myocardial Drp1 protein and mRNA was determined by immunohistochemistry and real-time reverse transcriptase polymerase chain reaction, respectively.Results Compared with group S, the MDA content was significantly increased, the SOD activity was decreased, the expression of Drp1 protein and mRNA was up-regulated, and AI was increased in Ⅰ/R, DS, and DI/R groups (P＜0.05).Compared with group Ⅰ/R, the MDA content was significantly increased, the SOD activity was decreased, the expression of Drp1 protein and mRNA was up-regulated, AI was increased, and the myocardial infarct size was enlarged in group DI/R (P＜0.05).Compared with group DS, the MDA content was significantly increased, the SOD activity was decreased, the expression of Drp1 protein and mRNA was up-regulated, AI was increased, and the myocardial infarct size was enlarged in group DI/R (P＜0.05).The pathological changes was aggravated in group DI/R compared with group Ⅰ/R.Conclusion Myocardial I/R injury is aggravated in diabetic rats, and the mechanism may be associated with up-regulated expression of myocardial Drp1.