The capability of the synchronization modulation (SM) technique in enhancing the function of Na/K pumps has been demonstrated in various cells and tissues, including cardiomyocytes, a monolayer of cultured MDCK kidney cells, peripheral blood vessels, and frog skeletal muscles. This study characterized the membrane potential hyperpolarization induced by SM in both physiological and high [K+]o conditions on single skeletal muscle fibers. The results showed that SM could consistently induce membrane potential hyperpolarization by a few millivolts, and this hyperpolarization was not possible in the presence of ouabain. In contrast, the same electrical pulses but with random frequencies, constant frequencies, or synchronization with backward-modulation could not hyperpolarize the membrane potential. Prolonged field application and higher field intensity enhanced the effects of SM-induced hyperpolarization. Finally, the effect of SM was tested on skeletal muscle fibers incubated in a solution with high external potassium. Results showed that the SM electric field could hyperpolarize the membrane potential even if the external K+ concentration was higher than the normal, which implied the therapeutic effects of the SM electric field on the hyperkalemic situation.

中文翻译：

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在生理和高钾血症条件下，Na / K泵的同步调制引起膜电位超极化。

同步调制（SM）技术增强Na / K泵功能的能力已在各种细胞和组织中得到证实，包括心肌细胞，培养的单层MDCK肾细胞，外周血管和青蛙骨骼肌。这项研究的特点是在生理和高[K +] o条件下，SM在单个骨骼肌纤维上引起的膜电位超极化。结果表明，SM可以持续诱导几毫伏的膜电位超极化，而在哇巴因存在下不可能发生这种超极化。相反，相同的电脉冲却具有随机频率，恒定频率或与反向调制同步不会使膜电位超极化。延长的野外应用和更高的场强增强了SM诱导的超极化效应。最后，测试了SM在骨骼肌纤维中的作用，该骨骼肌纤维在高外部钾溶液中孵育。结果表明，即使外部K +浓度高于正常水平，SM电场也可使膜电位超极化，这暗示了SM电场对高钾血症的治疗作用。