Chinese Journal Of Clinical Anatomy ›› 2016, Vol. 34 ›› Issue (2): 180-185.doi: 10.13418/j.issn.1001-165x.2016.02.013

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Expression of subtypes acetylcholine receptors in donor and recipient muscles after musculocutaneous nerve transection and reconstruction of elbow flexion in rats

YI Xiao-dong1, YANG Sheng-bo2   

  1. 1.Department of Histology and Embryology,  2.Department of Anatomy, Zunyi Medical college, Zunyi563003, China
  • Received:2015-08-31 Online:2016-03-25 Published:2016-04-14

Abstract:

Objective To explore the expression changes of acetylcholinereceptors(AChR)ε and γ subtypes (ε-AChR and γ-AChR) in the recipient muscle (biceps brachii) and donor muscle (oblique part of pectoralis major) after musculocutaneous nerve transection and elbow flexion reconstruction, and to provide a scientific guidance for the prevention and treatment of donor and recipient muscles’ atrophy. Methods Seventy adult Sprague Dawley rats were randomly divided into group A (normal); groups B1 and B2 (2w and 4w post-musculocutaneous nerve transection); groups C1 and C2 (2w and 4w post-false-reconstruction of elbow flexion); groups D1 and D2 (2w and 4w post-reconstruction of elbow flexion); There were 7 animal groups, and each group had 10 rats. Muscle wet weights were assessed, muscle fiber cross-sectional area were measured after H&E staining. ε-AChR and γ-AChR mRNA expressions were detected by RT-PCR. ε-AChR and γ-AChR protein expressions were detected by western blot technology. Results Compared with rats in group A, rats in group B became limp after musculocutaneous nerve transection, and the foraging movements were restricted, the weight of biceps brachii (recipient muscle) muscle shrunk gradually, the cross-sectional area decreased, the ε-AChR mRNA and protein expressions were downregulated. The γ-AChR expression reappeared later and followed an increasing trend gradually; However, the aboveme ntioned changes were far worse in group C and gradually improved in group D while expression of γ-AChR and ε-AChR in pectoralis major(donor muscle) showed only transient changes. Conclusions The transfer of the oblique part of the pectoralis major for elbow flexion reconstruction after musculocutaneous nerve transection can upregulate ε-AChR and downregulate γ-AChR in the recipient muscle and improve the function of elbow flexion in rats.

Key words: Musculocutaneous nerve injury, Elbow flexion reconstruction, Epsilon-acetylcholine receptors, Gamma-acetylcholine receptors