摘要
目的：探讨活性氧过氧化氢（Ｈ２Ｏ２）对心肌细胞损伤作用。方法：用不同浓度的 Ｈ２Ｏ２作用于新生鼠培养心肌细胞，通过琼脂糖凝胶电泳、Ｇｉｅｍｓａ染色和流式细胞仪等方法观察Ｈ２Ｏ２对心肌细胞的凋亡性损伤作用，同时检测培养介质中乳酸脱氢酶（ＬＤＨ）和丙二醛（ＭＤＡ）等生化指标的改变。结果：５ｍｍｏｌ／Ｌ Ｈ２Ｏ２作用于培养心肌细胞６ｈ，在琼脂糖凝胶电泳上出现梯状ＤＮＡ带； Ｇｉｅｍｓａ染色细胞涂片可见到染色体浓聚或边缘化，成新月型聚集在核膜周边，并有凋亡小体的存在；流式细胞仪可检测出亚二倍体峰的出现。结论：Ｈ２Ｏ２具有浓度和时间依赖关系诱导心肌细胞的调亡，在低浓度Ｈ２Ｏ２（＜１ｍｍｏｌ／Ｌ）导致培养心肌细胞的早期生物化学改变，自由基含量升高，膜通透性增加，同时伴有少量心肌细胞调亡；而在高浓度Ｈ２Ｏ２（＞１０ｍｍｏｌ／Ｌ）时会造成培养心肌细胞的坏死性死亡，细胞膜崩塌，脂质过氧化物（ＭＤＡ）大量产生，ＬＤＨ大量泄漏，ＤＮＡ琼脂糖凝胶电泳出现弥散（ｓｍｅａｒ）泳带；５～１０ ｍｍｏｌ／Ｌ Ｈ２Ｏ２诱导大量心肌细胞凋亡性死亡，同时伴有 ＬＤＨ和 ＭＤＡ含量升高等生物化学的改变。
AIM: To study apoptotic injury induced by aeactive oxygen species - hydrogen peroxide (H2O2) on cardiac myocytes. METHODS: Cultured rat neonatal cardiac myocytes were treated with H2O2 of various concentra- tion to observe apoptoitic injury of cardiomyocytes by agarose gel electrophoresis, Giemsa - stained smears of cell, and flow cytometry, meanwhile lactate dehydrogenas (LDH) and malondialdehyde (MDA) were determined to assess the effect of H2O2 on lipid peroxidation and permeability of the plasma membrane. RESULTS: 5 mmol/L H2O2 caused culted cardiomyocytes apoptotic morophological characteristics, including nucleosomal DNA fragmentation in my- ocytes by agarose gell electrophoresis (DNA ladder), cell shrinkage, nuclear condensation, and chromatin margin by Giemsa-stained cell smears, and aneuploid peak (AP) - apoptotic bodies occurence by flow cytometry. CONCLU- SONS: H2O2 - induced apotosis in myocytes was a the - and concentration - dependent process, Treatment with low concentration of H2O2(<1mmol/L) only caused cardiomyocyted early biochemical changes, such as increase of the radicals level. and membrane permeability, which were pro - apoptotic injurious features. High concentration of H2O2 (>10 mmol/L) rapidly induced a necrotic form of death characterized by smeared patterns of DNA digestion on agarose gel electrophoresis and lethal membrane disuption (as measured by LDH release). Exposure of 5 - 10 mmol/ L H2O2 induced cardiomyocytes apoptosis concurrently with biochemical changes of LDH and MDA increase in the medium.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2000年第5期457-461,I000,共6页
Chinese Journal of Pathophysiology
关键词
过氧化氢
心肌细胞
细胞凋亡
新生大鼠
Oxygen
Hydrogen peroxide
Myocardium
Cells, cultured
Cell death
