To investigate the effect of BFR on muscle atrophy and gene expression levels during cast immobilization in humans, we recruited 10 healthy males who were randomly divided into the control and BFR treatment groups. All subjects were immobilized with a cast for 14 days. BFR treatment was conducted only in the BFR group. We evaluated cross sectional area (CSA) of thigh muscles by magnetic resonance imaging before and 14 days after cast immobilization. A percutaneous biopsy of the vastus lateralis muscle (VL) was performed before and 1, 7, and 14 days after cast immobilization. Expression of genes related to muscle atrophy and synthesis were evaluated using real-time PCR.
The CSA of the VL and the thigh flexor muscles were significantly decreased in both groups; however, percent decrease in CSA was significantly smaller in the BFR group compared with the control group. In two-way repeated ANOVA analysis, the time × treatment interaction in gene expression of the muscle-specific ubiquitin ligases muscle ring finger 1 (MuRF1) was significant, and elevated MURF1 expression level by cast immobilization was seemed to be suppressed by the BFR treatment.
BFR treatment may prevent reduced VL and thigh flexor muscles and increased MuRF1 expression level during cast immobilization. Further study is required to confirm these results.
为了研究BFR对人体石膏固定过程中肌肉萎缩和基因表达水平的影响,我们招募了10名健康男性,随机分为对照组和BFR治疗组.所有受试者用石膏固定14天。仅在BFR组中进行BFR治疗。我们在固定石膏之前和之后14天通过磁共振成像评估了大腿肌肉的横截面积(CSA)。在固定前和固定后1、7和14天进行了股外侧肌(VL)的经皮活检。使用实时PCR评估与肌肉萎缩和合成相关的基因的表达。
两组的VL和大腿屈肌的CSA均显著降低;然而,与对照组相比,BFR组的CSA下降百分比明显较小。在双向重复方差分析中,肌肉特异性泛素连接酶肌肉无名指1(MuRF1)基因表达的时间×处理相互作用是显着的,BFR处理似乎抑制了通过cast固定引起的MURF1表达水平的升高。
BFR治疗可以防止在石膏固定期间减少的VL和大腿屈肌以及增加的MuRF1表达水平。需要进一步的研究来证实这些结果。