【摘要】 目的探讨工频磁场对骨骼肌肌质网钙转运动力学的影响。方法利用动态光谱法检测0.4mT、50Hz正弦磁场辐照过的骨骼肌肌质网Ca2+转运和钙泵活性,用3H兰尼碱结合实验检测Ca2+释放通道的活性,用荧光偏振法检测肌质网膜的流动性等。结果0.4mT、50Hz正弦磁场辐照导致提取的肌质网囊泡Ca2+摄取初速率由每秒(29.18±3.90)pmol/mg下降到(24.60±3.81)pmol/mg,钙泵的活性由每分钟(0.93±0.05)μmol/mg下降到(0.69±0.07)μmol/mg;导致Ca2+释放初速率由每秒(4.83±0.82)pmol/mg上升到(5.65±0.43)pmol/mg,3H兰尼碱结合度由(1.10±0.12)pmol/mg上升到(1.16±0.13)pmol/mg,分别上升了15%和5%。结论0.4mT工频磁场辐照引起的肌质网Ca2+摄取下调和Ca2+释放上调是由于肌质网钙泵活性降低和Ca2+释放通道活性升高所致。更多还原

【Abstract】 Objective To investigate the effects of power frequency magnetic field on the Ca 2+ transport dynamics of isolated sarcoplasmic reticulum vesicles. Methods The assays of Ca 2+ uptake time course and the Ca 2+-ATPase activity of sarcoplasmic reticulum vesicles were investigated by using dynamic mode of spectrometry with a Ca 2+ dye;Ca 2+ release channel activation was examined by 3H-ryanodine binding and Ca 2+ release assays;membrane fluidity of sarcoplasmic reticulum vesicles was examined by fluorescence polarization,without or with exposure to the vesicles at a 0.4 mT, 50 Hz sinusoidal magnetic field. Results 0.4 mT, 50 Hz sinusoidal magnetic field exposure caused about a 16% decline of the initial Ca 2+ uptake rate from a (29.18±3.90) pmol·mg -1·s -1 to a (24.60±3.81) pmol·mg -1·s -1 and a 26% decline of the Ca 2+-ATPase activity from (0.93±0.05) μmol·mg -1·min -1 to (0.69±0.07) μmol·mg -1·min -1 of sarcoplasmic reticulum vesicles,whereas caused a 15% increase of the initial Ca 2+ release rate from (4.83±0.82) pmol·mg -1·s -1 to (5.65±0.43) pmol·mg -1·s -1 and a 5% increase in 3H-ryanodine binding to the receptor from (1.10±0.12) pmol/mg to (1.16±0.13) pmol/mg,respectively. Conclusion The decline of Ca 2+-ATPase activity and the increase of Ca 2+ release channel activity should result in a down-regulation of Ca 2+ dynamic uptake and an up-regulation of Ca 2+ release induced by exposing the sarcoplasmic reticulum to a 0.4 mT, 50 Hz power frequency magnetic field.更多还原