Stability of motor endplates is greater in the biceps than in the interossei in a rat model of obstetric brachial plexus palsy
Bo Li
Liang Chen
Yu-Dong Gu
1.Department of Hand Surgery,Huashan Hospital and Institutes of Biomedical Sciences,Fudan University,Shanghai,China;Shanghai Key Laboratory of Peripheral Nerve and Microsurgery,Shanghai,China2.Department of Hand Surgery,Huashan Hospital and Institutes of Biomedical Sciences,Fudan University,Shanghai,China;Shanghai Key Laboratory of Peripheral Nerve and Microsurgery,Shanghai,China3.Department of Hand Surgery,Huashan Hospital and Institutes of Biomedical Sciences,Fudan University,Shanghai,China;Shanghai Key Laboratory of Peripheral Nerve and Microsurgery,Shanghai,China
摘要：The time window for repair of the lower trunk is shorter than that of the upper trunk in patients with obstetric brachial plexus palsy. The denervated intrinsic muscles of the hand become irreversibly atrophic much faster than the denervated biceps. However, it is unclear whether the motor endplates of the denervated interosseous muscles degenerate more rapidly than those of the denervated biceps. In this study, we used a rat model of obstetric brachial plexus palsy of the right upper limb. C5–6 was lacerated distal to the intervertebral foram-ina, with concurrent avulsion of C7–8 and T1, with the left upper limb used as the control. Bilateral interossei and biceps were collected at 5 and 7 weeks. Immunofluorescence was used to assess the morphology of the motor endplates. Real-time quantitative polymerase chain reaction and western blot assay were used to assess mRNA and protein expression levels of acetylcholine receptor subunits (α, β and δ), rapsyn and β-catenin. Immunofluorescence microscopy showed that motor endplates in the denervated interossei were fragmented, while those in the denervated biceps were morphologically intact with little fragmentation. The number and area of motor endplates, relative to the control side, were significantly lower in the denervated interossei compared with the denervated biceps. mRNA and protein expression levels of acetylcholine receptor subunits (α, β and δ) were significantly lower, whereas β-catenin protein expression was higher, in the de-nervated interossei compared with the denervated biceps. The protein expression of rapsyn was higher in the denervated biceps than in the denervated interossei at 7 weeks. Our findings demonstrate that motor endplates of interossei are destabilized, whereas those of the biceps remain stable, in the rat model of obstetric brachial plexus palsy. All procedures were approved by the Experimental Animal Ethics Com-mittee of Fudan University, China (approval No. DF-187) in January 2016.
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论文发表日期：2020-09-28
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：8( 1678-1685 )
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