氧化应激对左心室内外膜收缩力及钙瞬变的影响  

Effect of Oxidative Stress on the Contraction and Calcium Transient in the Epicardial and Endocardial Myocytes of Left Ventricle

作　　者：潘文[1] 杨梓琪[1] 程均[1] 钱成[1] 王扬淦[1] 

机构地区：[1]武汉大学中南医院心内科,湖北武汉430071

出　　处：《武汉大学学报（医学版）》2016年第5期714-717,共4页Medical Journal of Wuhan University

基　　金：国家自然科学基金资助项目(编号:81270304)

摘　　要：目的:探讨氧化应激对左心室内、外膜心肌细胞收缩力及钙瞬变的影响。方法:采用Langendorff灌流术分离小鼠左心室内、外膜心肌细胞。采用高速CCD摄像机系统和双激发荧光倍增系统同步测量内外膜心肌细胞肌小节收缩舒张功能和胞内钙瞬变。结果:H2O2(100μmol/L,灌流1min)显著增加内、外膜心室肌细胞的收缩幅度和钙瞬变幅度,但对内膜的增加幅度显著大于外膜。H2O2使内外膜心肌细胞收缩振幅分别增加了(0.015 5±0.001 7)μm和(0.009 6±0.000 9)μm(P<0.05);使细胞钙瞬变振幅(F340/380)分别增加了0.073 7±0.004 3和0.028 4±0.001 4(P<0.05)。结论:心室内膜心肌细胞较外膜心肌细胞对氧化应激有更高的反应性;在氧化应激时心肌细胞肌织网钙释放增加使心肌收缩力增强,而内膜心肌细胞在心室肌的这一正性变力反应中起到关键性作用。Objective：To determine the transmural reaction of contraction and calcium transient to oxi- dative stress in the left ventricle. Methods： Endocardial （Endo） and epicardial （Epi） myocytes were isolated from C57/BL6 mice by Langendorff perfusion. Sarcomere contraction and Ca2＋ transient were recorded simultaneously using a high speed CCD video camera and a dual excitation fluorescence photomultiplier system. Results： Perfusion of H2O2 （100 mol/L, for 1 min） signifi- cantly increased the amplitudes of sareomere shortening and calcium transient in both Endo and Epi myocytes, with much greater increase in the Endo myocytes. H2O2induced an increase in sar- comere shortening in Endo by （0. 015 5±0. 001 7）μm （n=10） and in Epi by （0. 009 6±0. 000 9） μm （n=12, P〈0.05）, respectively. Similarly, H2O21ed to an increase of Ca2＋ transient ampli- tude in Endo by （0. 073 7±0. 004 3）F340/380 （n=10） and in Epi myocytes by （0. 028 4±0. 001 4） F340/380 （n=12,P〈0.05）. Conclusion： Endo myoeytes are more sensitive to oxidative stress than Epi my.ocytes. Oxidative stress increases cardiac contractility by increasing SR calcium release, while the endomyoeardium plays a major role in this positive inotropie reaction.

关 键 词：心肌收缩 钙瞬变 过氧化氢 氧化应激 

分 类 号：R331.31[医药卫生—人体生理学]