小鼠左心室肌细胞收缩与钙瞬变对频率和氧化压力应答的跨膜梯度

发布时间：2018-12-17 00:25

【摘要】：目的：研究小鼠左心室肌细胞收缩与钙瞬变对频率和氧化压力应答的跨膜梯度。材料：6周鼠龄的C57雄性小鼠左心室内／外膜层肌细胞分离采用Langendorff灌流术。心肌细胞钙瞬变和收缩舒张功能同步检测使用的是双激光荧光光电倍增系统。结果：实验统计了来自6只小鼠的22个内膜心肌细胞和26个外膜心肌细胞,发现在刺激频率为lhz,台式液灌流情况下,正常小鼠左心室内膜心肌细胞的舒张期钙浓度为0.521±0.023(F340/380),大于外膜心肌细胞的0.466±0.022(F340/380)(p0.05)；钙瞬变振幅为0.241±0.014(F340/380)大于外膜心肌细胞的0.203±0.011(F340/380)(p0.05)；肌织网钙释放速率为20.89±0.923(F/s)小于外膜心肌细胞的22.823±0.814 F/s(p0.05)；肌织网钙回收速率为2.459±0.292(F/s),小于外膜心肌细胞的3.267±0.245(F/s)(p0.05)。同时,内膜心肌细胞的肌小节长度为1.816±0.033(um)小于外膜心肌细胞的1.834±0.011(um)(p0.05)；肌小节收缩振幅为0.034±0.005(um)小于外膜心肌细胞的0.023±0.002(um)(p0.05)。刺激频率增加后,内膜心肌细胞的舒张期钙浓度增加了16.29%±2.64%,大于外膜心肌细胞的8.91%±1.12%(p0.05)；收缩期钙瞬变振幅增加了32.12%±5.69%,大于外膜心肌细胞的14.12%±1.67%(p0.05)；胞质钙回收速率的增加129.29%±24.72%,大于外膜心肌细胞的55.50%±4.55%(p0.05)。相应地,肌小节收缩振幅增加了250.30%±42.08%(n=12)大于外膜层心肌细胞的49.97%±7.56%(n=23,P=0.020.05)。肌小节缩短的最大速率加速了433.15%±71.25%(n=12)大于外膜层心肌细胞75.74%±13.95%(n=23,P=0.0090.05)。当给予100 uM H202暴露1min使内膜心肌细胞收缩振幅增加了0.0155±0.0017(um)大于外膜心肌细胞的0.0096±0.0009(um),P0.05。内膜心肌细胞钙瞬变振幅增加了0.0737±0.0043(F340/380)大于外膜心肌细胞的0.0284±0.0014(F340/380),P0.05。正常小鼠内外膜心肌细胞的钙瞬变振幅存在0.045±0.006(F340/380)的差异,而心衰小鼠内外膜心肌细胞的钙瞬变差异为0.005±0.001(F340/380)(P0.05)结论：小鼠左心室内膜心肌细胞钙瞬变振幅和收缩力均强于外膜心肌细胞。内膜层心肌细胞钙瞬变和收缩舒张慢于外膜层心肌细胞。内膜层心肌细胞钙瞬变和收缩舒张对频率的反应较为膜层心肌细胞更敏感。低浓度段时间的氧化压力使内膜心肌细胞收缩和钙瞬变代偿性增加大于外膜心肌细胞。心衰小鼠内外膜心肌细胞钙瞬变的跨膜梯度消失。
[Abstract]:Aim: to study the transmembrane gradient of contractile and calcium transient responses to frequency and oxidative pressure in mouse left ventricular myocytes. Materials: the left ventricular / outer lamellar myocytes of 6 week old C57 male mice were isolated and perfused with Langendorff. Double-laser fluorescence photomultiplier system is used for simultaneous detection of calcium transient and systolic-diastolic function of myocardial cells. Results: 22 endomyocytes and 26 adventitia cardiomyocytes from 6 mice were counted. The results showed that the stimulation frequency was lhz, table perfusion. The diastolic calcium concentration of left ventricular endomyocytes in normal mice was 0.521 卤0.023 (F340 / 380), which was higher than that of adventitia cardiomyocytes (0.466 卤0.022) (p0.05). The transient amplitude of calcium was 0.241 卤0.014 (F340 / 380) and 0.203 卤0.011 (F340 / 380) in epicardial cardiomyocytes (p0.05). The calcium release rate of muscle mesh was 20.89 卤0.923 (F / s) less than that of 22.823 卤0.814 F / s of epicardial cardiomyocytes (p0.05). The calcium recovery rate of muscle netting was 2.459 卤0.292 (F / s), which was lower than 3.267 卤0.245 (F / s) of epicardial cardiomyocytes (p0.05). At the same time, the length of muscle section of endomyocytes was 1.816 卤0.033 (um), which was smaller than that of adventitia cardiomyocytes (1.834 卤0.011 (um) (, p0.05). The contractile amplitude of muscle section was 0.034 卤0.005 (um), which was lower than that of adventitia cardiomyocytes (0.023 卤0.002 (um) (, p0.05). After stimulation, the diastolic calcium concentration increased by 16.29% 卤2.64%, which was higher than that of adventitia cardiomyocytes (8.91% 卤1.12%, p0.05). The amplitude of transient calcium in systolic phase increased by 32.12% 卤5.69%, which was higher than that of adventitia cardiomyocytes by 14.12% 卤1.67% (p0.05). The recovery rate of calcium in cytoplasm was increased by 129.29% 卤24.72%, which was higher than that of adventitia cardiomyocytes by 55.50% 卤4.55% (p0.05). Correspondingly, the contractile amplitude of muscle section was increased by 250.30% 卤42.08% (nm12) than that of adventitia cardiomyocytes (49.97% 卤7.56%). The maximal rate of shortening of muscle section was increased by 433.15% 卤71.25% (nm12) than that of adventitia cardiomyocytes (75.74% 卤13.95%). When exposed to 100 uM H202, the contractile amplitude of endomyocytes was increased by 0.0155 卤0.0017 (um) than by 0.0096 卤0.0009 (um), P0.05 of epicardial cardiomyocytes. The amplitude of calcium transient was increased by 0.0737 卤0.0043 (F340 / 380) in endomyocytes than 0.0284 卤0.0014 (F340 / 380) in adventitial cardiomyocytes (P0.05). In normal mice, the amplitude of calcium transient was 0.045 卤0.006 (F340 / 380). The difference of calcium transient was 0.005 卤0.001 (F340 / 380) (P0.05). Conclusion: the amplitude and contractility of calcium transient in mouse left ventricular endomyocytes are stronger than that of adventitia cardiomyocytes. Calcium transient and diastolic activity of endometrial myocardial cells was slower than that of adventitia cardiomyocytes. Calcium transient and contractile relaxation were more sensitive to frequency than membranous myocardial cells. The contractility and calcium transient compensability of myocardial cells were increased by oxidative pressure at low concentration than that of adventitia cardiomyocytes. The transmembrane gradient of calcium transient in cardiac myocytes of heart failure mice was disappeared.
【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R54

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