缺血/再灌注损伤对心肌细胞核膜NTPase活性和mRNA出核转运的影响  

INFLUENCE OF MYOCARDIAL ISCHEMIA/REPERFUSION in vitro ON NUCLEAR ENVELOPE NTPase ACTIVITY AND mRNA EXPORT IN THE CARDIOMYOCYTE OF RABBITS

作　　者：夏春芳[1] 刘乃奎[1] 扬军[1] 庞永正[1] 霍勇[1] 唐朝枢[1] 

机构地区：[1]北京大学第一医院心血管研究所,北京100034

出　　处：《中国应用生理学杂志》2001年第2期161-165,共5页Chinese Journal of Applied Physiology

基　　金：国家自然科学基金资助项目! (39870 35 5 )

摘　　要：目的 :观察家免心肌缺血 /再灌注 (I/R)损伤时心肌细胞核膜核苷三磷酸酶 (NTPase)动力学及mRNA出核转运的变化。方法 :制备家兔离体心脏I/R模型 ,密度梯度离心法制备心肌细胞核膜 ,按Tiffany等的方法测定NT Pase活性及mRNA的转运率。结果 :心肌细胞核膜NTPase在以ATP或GTP为底物时 ,与对照组比较 ,I/R组最大反应速率 (Vmax)分别降低 2 6 %及 2 2 % (P <0 .0 1)。Km值分别升高 5 4%及 72 % (P <0 .0 1) ;而缺血组Vmax及Km值较对照组无明显差异。以ATP或GTP启动反应时I/R组 10min内心肌细胞核mRNA转出率分别较对照组降低 2 7%及 32 % (P <0 .0 1) ;而缺血组与对照组相比并无显著性差异 (P >0 .0 5 )。结论 :心肌缺血 /再灌注损伤时 ,心肌细胞核膜受损 ,核膜上NTPase活性降低 ,导致细胞核膜mRNA出核受阻 ,从而可能影响蛋白质的合成表达。Aim: To study the alteration of nuclear envelope associated NTPase activity and mRNA nucleocytoplamic transport in rabbit cardiomyocyte following in vitro ischemia and reperfusion.Methods:The model of myocardial perfusion in rabbit was used to produce myocardial I/R injury and cardiomyocyte nuclear envelope vesicles were prepared by density gradient centrifugation for the assay of mRNA transport rate and NTPase activity.Results: NTPase activity was reduced and mRNA transport rate was significantly decreased in I/R ( P <0.01) but not in ischemia group( P >0.05).Conclusion:The nuclear envelope vesicles had been injured following ischemia and reperfusion and resulted in NTPase activity reduced and egress of mRNA interrupted,and therefore may lead to decreasing of protein synthesis.

关 键 词：心肌缺血 再灌注损伤 核膜核苷三磷酸酶 MRNA NTPASE 核转运 

分 类 号：R542.2[医药卫生—心血管疾病]