摘要
目的 为探讨细胞凋亡在急性心肌梗塞时心肌细胞中的意义。方法 用末端原位标记 (TUNEL)法、DNA电泳和电镜三种方法检测兔急性心梗模型中梗塞区心肌细胞的凋亡。结果 TUNEL法发现 :兔急性心梗模型中梗塞区心肌细胞凋亡千分率在冠脉结扎前 (0h)和结扎后 1h、2h、3h、4h、6h、8h、12h的改变如下 :0h组 (31 0 0± 14 0 0‰ )和 12h组 (6 8 0 0±31 72‰ ) <1h组 (142 33± 5 3 5 2‰ ) <2h组 (370 83± 6 6 0 1‰和 8h组 (32 1 17± 86 43‰ ) <3h组 (5 86 83± 5 5 0 2‰ ) <4h组(836 17± 43 73‰ ) (P均 <0 0 5 ) ,即急性心梗心肌细胞凋亡数在冠脉结扎后 1h时开始逐渐增多 ,到 4h时达高峰 ,其后逐渐下降 ,到 12h时已逐渐降至正常。DNA梯形电泳显示在兔冠脉结扎后 3h、4h、6h时梗塞区的心肌细胞均出现相差约 180～2 0 0bp的DNA阶梯 (Ladder) ,而其它各时间点的心肌细胞未见有相差约 180～ 2 0 0bp的DNA条带。电镜观察显示在兔冠脉结扎后梗塞区内的心肌细胞核膜完整、染色质浓集、电子密度增加的凋亡特征 ,有的则出现核膜破裂、染色质溶解成碎屑的坏死现象。结论 兔冠脉在结扎 3～ 6h时梗塞的心肌细胞凋亡特征最明显 ,细胞凋亡在急性心梗心肌细胞死亡中起重要作用。
Objective To explore the significances of myocyte apoptosis in acute myocardial infarction(AMI). Methods Myocyte apoptosis in AMI rabbit model was studied by TdT-Mediated dUTP Nick End Labling(TUNEL), DNA laddering on agarose gel electrophoresis and electron microscope. Results In the AMI rabbit model, TUNEL methlod showed that the permillage of apoptotic myocytes in infarct area at 1 h, 2 h, 3 h, 4 h, 6 h, 8 h, 12 h after coronary artery occlusion and before coronary artery occlusion(Oh) were: Oh group (31.00±14.00‰) and 12 h group (68.00±31.72‰)<1 h group (142.33±53.52‰)<2 h group (370.83±66.01‰) and 8 h group(321.17±86.43‰)<3 h group (586.83±55.02‰)<4 h group (836.17±43.73‰)( P <0.05), The number of apoptotic myocytes was increased gradually after 1 h occlusion of coronary artery, reaching to the top at the 4th hour, then decreased slowly to normal at the 12th hour. DNA laddering on agarose gel electrophoresis demonstrated that the small molecule DNA fragment (180～200 bp) in myocytes of infarct area was observed at 3 h, 4 h, 6 h after the coronary artery occlusion, but not found at any other times. Electron microscopy showed that characteristics of myocyte apoptosis episodes, including intact nuclear membrane, condensed chromatin and increased electron denes. The others showed broken membrane, chromatin dissolved into pieces, lysed and empited nuclear-characteristics of necrosis. Conclusions These morphologic changes suggest that the apoptotic characteristics of myocytes in the infarct areas are most obvious during 3～6 h after coronary artery occlusion, apoptosis is the important form of myocyte death in AMI.[
出处
《中国急救医学》
CAS
CSCD
北大核心
1999年第10期577-580,共4页
Chinese Journal of Critical Care Medicine
基金
卫生部基金!1996-1-116
关键词
细胞凋亡
急性
心肌梗塞
兔
Apoptosis
Acute myocardial infarction
Rabbit
