Rehabilitation Medicine Center, West China Hospital, Sichuan University, Chengdu, P. R. China.
Rehabilitation Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, P. R. China.
Bioelectromagnetics. 2021 Sep;42(6):441-454. doi: 10.1002/bem.22344. Epub 2021 Jun 3.
A pulsed electromagnetic field (PEMF) can promote osteogenesis. However, studies have shown variation in the signal characteristics in terms of waveform type, intensity, frequency, and treatment duration. Among the factors that affect electromagnetic fields, frequency plays a major role. However, few studies have investigated the effects of PEMF at different frequencies in osteoporotic mice. Therefore, our objective was to determine the effect of PEMF frequency in osteoporotic mice. Forty 3-month-old female mice were randomly divided into the following five groups: sham, OVX, and OVX followed by 1.6-mT PEMF exposure groups (8 Hz, 50 Hz, and 75 Hz, 1.6 mT). The PEMF was applied for 1 h/day, 7 days/week, for 4 weeks. After 4 weeks, the micro-computed tomography showed that PEMF with (50 and 75 Hz) ameliorated the deterioration of bone microarchitecture. Improvements in the bone histological analysis were identified for PEMF with 50 and 75 Hz groups compared with the ovariectomy (OVX) controls. Osteoclast numbers were decreased in PEMF with (50 and 75 Hz). Moreover, the real-time PCR demonstrated PEMF with (50 and 75 Hz) significantly promoted the expression of the osteoblast-related genes (ALP, OCN, Runx2), and increased the serum PINP. PEMF with (50 and 75 Hz) exerted significant inhibitory effects on the osteoclast-related mRNA expression (CTSK, NFATc1, TRAP) and bone resorption markers CTX-I and IL-1β. Taken together, our results showed that PEMF at 50 and 75 Hz with 1.6 mT significantly ameliorate the deterioration of bone microarchitecture in OVX mice. The inhibitory effect of PEMF may be associated with IL-1β inhibition. © 2021 Bioelectromagnetics Society.
脉冲电磁场（PEMF）可促进成骨。然而，研究表明，在波形类型、强度、频率和治疗时间方面，信号特征存在差异。在影响电磁场的诸多因素中，频率起着重要作用。然而，很少有研究调查不同频率的 PEMF 在骨质疏松症小鼠中的影响。因此，我们的目的是确定 PEMF 频率对骨质疏松症小鼠的影响。将 40 只 3 月龄雌性小鼠随机分为以下五组：假手术组、卵巢切除组（OVX）和卵巢切除后接受 1.6-mT PEMF 暴露组（8 Hz、50 Hz 和 75 Hz，1.6 mT）。PEMF 每天 1 小时，每周 7 天，连续 4 周。4 周后，微计算机断层扫描显示，（50 和 75 Hz）的 PEMF 改善了骨微结构的恶化。与卵巢切除（OVX）对照组相比，50 Hz 和 75 Hz 组的骨组织学分析显示出改善。PEMF 可减少（50 和 75 Hz）破骨细胞数量。此外，实时 PCR 表明，（50 和 75 Hz）的 PEMF 显著促进了成骨相关基因（ALP、OCN、Runx2）的表达，并增加了血清 PINP。（50 和 75 Hz）的 PEMF 对破骨细胞相关基因（CTSK、NFATc1、TRAP）的表达和骨吸收标志物 CTX-I 和 IL-1β 具有显著的抑制作用。总之，我们的研究结果表明，1.6 mT 的 50 Hz 和 75 Hz 的 PEMF 可显著改善 OVX 小鼠骨微结构的恶化。PEMF 的抑制作用可能与 IL-1β 抑制有关。
