硫酸锌诱导金属硫蛋白减轻再灌注肺细胞凋亡的实验研究  

Effects of metallothionein induced by ZnSO_4 on pneumocyte apoptosis after lung ischemia/reperfusion injury in rats

作　　者：石璐[1,2] 贾旭广[1,2] 邱晓晓 钱小英[3] 汪洋[1] 许冬武[1] 王万铁[1] 

机构地区：[1]温州医学院病理生理教研室 [2]桐乡市卫生学校 [3]温州市第三人民医院呼吸内科

出　　处：《中国临床药理学与治疗学》2010年第10期1110-1116,共7页Chinese Journal of Clinical Pharmacology and Therapeutics

基　　金：温州市科技计划项目(Y20060083);温州市医药卫生科研项目(2009A004)

摘　　要：目的:观察硫酸锌诱导金属硫蛋白对再灌注肺细胞凋亡的影响。方法:健康雄性SD大鼠24只,随机分为对照组(C组)、模型组(I/R组)和研究组(M组)。对比观察各组肺组织中金属硫蛋白的含量,血清中丙二醛(MDA)、超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)活力及含量变化,原位缺口末端标记法(TUNEL)检测肺组织细胞凋亡情况,免疫组化及RT-PCR法检测肺组织中Bax、Bcl-2蛋白和基因的表达,透射电镜观察肺组织超微结构的改变。结果:I/R组与C组相比,肺组织中金属硫蛋白的含量显著下降,MDA含量、MPO活力明显升高,SOD活力明显下降(P<0.05或P<0.01),肺组织原位细胞凋亡检测显示I/R组凋亡指数(AI)39.03±3.46显著高于C组2.88±0.34,Bcl-2/Bax比值在蛋白和基因水平明显降低(P<0.05或P<0.01),肺组织超微结构发生异常改变;金属硫蛋白组与I/R组相比肺组织中金属硫蛋白的含量显著升高(P<0.01),MDA含量、MPO活力明显下降,SOD活力明显升高(P<0.05或P<0.01),AI为15.50±1.02显著低于I/R组,并能明显升高Bcl-2/Bax比值及改善肺组织超微结构。结论:金属硫蛋白通过减轻脂质过氧化反应及中性粒细胞聚集,降低Bax/Bcl-2比值,使肺组织细胞凋亡减少,从而有效地减轻肺缺血/再灌注损伤。AIM：To investigate the effects of metallothionein induced by ZnSO4 on pneumocyte apoptosis after lung ischemia/reperfusion injury in rats.METHODS：Adult male Sprague-Dawley rats were randomly divided into 3 groups based upon the intervention（n=8）：control group（C）,LIR group（I/R）,LIR＋ ZnSO4 group（M）.At the end of the experiment,the content of metallothionein was tested in lung tissue;blood specimens drawn from the arteria carotis were tested for the content of Malondialdehyde（MDA）,the activity of Superoxide dismutase（SOD） and Myeloperoxidase（MPO）;the pneumocyte apoptosis index（AI） was achieved by terminal deoxynucleotidyl transferase mediated dUTP nick end abeling（TUNEL）;the expression of Bcl-2,Bax protein in lung tissue were accessed by quantitative immunohistochemistry（IHC） and Bcl-2,Bax mRNA by RT-PCR;ultrastructural changes of lung tissue were ob-served by transmission electron microscope.RESULTS：Metallothionein induced by ZnSO4 could significantly attenuate the MDA level,MPO activity and improve SOD activity in blood serum which was comparable to I/R and significantly reduced the number of TUNEL-positive cells vs.the I/R group,expressed as AI（% total nuclei） from 39.03±3.46 to 15.50±1.02（P0.01）.The protein and mRNA expression of Bcl-2,Bax showed that metallothionein significantly attenuated the ischemia/reperfusion-upregulated expression of Bax protein but improved the expression of Bcl-2 that improved the Bcl-2/Bax ratio（P0.05 or P 0.01）.There were abnormal changes of the ultrastructure in I/R,and markedly reversed in MT group.CONCLUSION：Metallothionein induced by ZnSO4 may attenuate pneumocyte apoptosis in LIRI by up-regulating expression of Bcl-2/Bax ratio and by inhibiting oxidant generation,neutrophils filtration.

关 键 词：肺 缺血/再灌注损伤 金属硫蛋白 硫酸锌 凋亡 

分 类 号：R363[医药卫生—病理学]