Objective To investigate the effects of sinusoidal magnetic field on isolated sarcoplas-mic reticulum (SR) calcium release channel (RyR1) function. Methods With the Ca2+ dynamic spectrum and isotope labeled methods, the Ca2+ release and [3H]-Ryanodine binding, the initial rates of NADH oxida-tion and the production of superoxide of SR exposed to 50 Hz sinusoidal magnetic field (MF) were investi-gated respectively. Results 0.4 mT, 50 Hz sinusoidal MF exposure for 30 min increased SR Ca2+ release initial rate about 35% from (10.82±0.89)pmol· mg-1 pro·s-1 to (14.69±1.21)pmol·mg-1 pro·s-1; and the [3H]-Ryanodine binding by about 15% from (2.13±0.05)pmol/mg pro to (2.45±0.07)pmol/mg pro, which regu-lated by 1 mmol/L NADH with 1 mmol/L NAD+. Meanwhile MF upregnlated the rate of NADH oxidation by about 22% from (0.88±0.11)×10-4 FI/s to (1.07±0.13)×10-4 FI/s and upregulated the production of super-oxide by about 32% from (0.99±0.09)×10-5 FI/s to (1.31±0.06)×10-5 FI/s. Conclusion 0.4 mT sinu-soidal MF increases the activity of RyR1 within the low redox potential environment, and promotes NADH oxidase activity and superoxide production.%目的 探讨正弦磁场对提取的骨骼肌肌质网(SR)囊泡钙释放通道(RyR1)的影响.方法 采用动态光谱法和同位素标记方法 ,分别检测了正弦磁场对SR囊泡Ca2+释放初速率、[3H]-Ryanodine平衡结合度、还原型辅酶(NADH)的氧化初速率和超氧(O·2-)产率的影响.结果 0.4 mT、50 Hz正弦磁场辐照SR囊泡30 min,由1 mmol/L NADH与1 mmol/L NAD调控的Ca2+释放初速率Con组为(10.82±0.89)pmol·mg-1 pro·s-1、MF组为(14.69±1.21)pmol·mg-1pro·s-1;上调了35%,[3H]-Ryan-odine平衡结合度上调15%,由(2.13±0.05)pmol/mg pro上升到(2.45±0.07)pmol/mg pro.另外,该磁场辐照SR囊泡30 min,导致NADH的氧化速率上调22%,由(0.88±0.11)×10-4FI/s上升到(1.07±0.13)×10-4FI/s;O·2-产率上调32%,由(0.99±0.09)×10-5FI/s上升到(1.31±0.06)×10-5FI/s. 结论 0.4 mT正弦磁场在低氧化还原电势环境下对RyR1有显著的激活,且该磁场促进了NADH氧化酶的活力和O·2-产率的增加.
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