Involvement of sympathetic nerve in the regulation of disuse atrophy of skeletal muscles: a preliminary study
10.3760/cma.j.cn115530-20250103-00004
- VernacularTitle:交感神经参与调控骨骼肌废用性萎缩的初步探究
- Author:
Dongliang CHENG
1
;
Mingming ZHANG
;
Jiang LIU
;
Junmin SHEN
;
Zhongqi WANG
;
Xinyu SUN
;
Duanyang WANG
;
Feifan CHANG
;
Haobo ZHANG
;
Pincong FU
;
Ming CHEN
;
Yi LI
;
Pengbin YIN
;
Licheng ZHANG
;
Peifu TANG
Author Information
1. 解放军总医院第四医学中心骨科医学部，国家骨科与运动康复临床医学研究中心，北京 100048
- Publication Type:Journal Article
- Keywords:
Lower extremity;
Muscle, skeletal;
Muscular atrophy;
Sympathetic nerve;
Norepinephrine;
Paraventricular nucleus of hypothalamus;
Immobilization
- From:
Chinese Journal of Orthopaedic Trauma
2025;27(3):242-249
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the changes in sympathetic nerve activity after lower limb immobilization and the role of sympathetic nerve in regulating disuse atrophy of skeletal muscles.Methods:The experiment was divided into the following 3 parts: ① Twelve 8-week-old male C57 mice were randomly divided into a blank control group and a hind limb fixation group ( n=6). The blank control group received no intervention while the hind limb fixation group received splint fixation of the hind limbs for 2 weeks before the musculoskeletal multi-dimensional characterization was completed at the behavioral, pathological and molecular levels. ② Thirty-six 8-week-old male C57 mice were selected and randomly divided into a control group and 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) ( n=6). The control group was fed normally until 14 days without any intervention while the 5 hind limb fixation groups were sampled after fixation for 1, 3, 5, 7 and 14 days, respectively. The level of norepinephrine in the serum and the expression level of tyrosine hydroxylase (TH), a marker of sympathetic nerve activity in the paraventricular nucleus of hypothalamus (PVN), were detected to observe the plasticity of sympathetic nerve activity. ③ Eighteen 8-week-old male C57 mice were selected and randomly divided into a blank control group, a hind limb fixation group and a hind limb fixation plus medication group ( n=6). The blank control group received no intervention while the 2 fixation groups were injected with phosphate buffer (PBS) and propranolol hydrochloride solution for 2 consecutive weeks, respectively. The parameters related to the skeletal muscles were compared between the 3 groups. Results:① Compared with the control group, the mass and function of skeletal muscles in the hind limb fixation group were statistically significantly decreased ( P<0.05). ② The levels of serum norepinephrine [(3.27±1.03) ng/mL, (9.21±1.05) ng/mL, (6.36±0.88) ng/mL, (3.84±1.00) ng/mL, and (3.91±0.75) ng/mL] and the PVN TH levels (42.00%±5.38%, 61.67%±5.57%, 55.82%±3.11%, 50.90%±2.53%, and 39.17%±9.07%) in the 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) were significantly higher than those in the control group [(1.81±0.72)] ng/mL and 23.33%±5.50%] ( P<0.05). ③ The wet weight of the gastrocnemius muscle [(93.50±4.32) mg] and the cross-section area of the tibial anterior muscle [(1,180.00±95.09) μm 2] in the hind limb fixation plus medication group were increased significantly compared with those in the hind limb fixation group [(80.83±9.99) mg and (907.80±121.00) μm 2] ( P<0.05). Conclusions:Overactivation of the sympathetic nervous system occurs in the mice model of skeletal muscle disuse atrophy after hind limb fixation. Inhibition of sympathetic nerve activity may reduce the severity of skeletal muscle atrophy at the lower limbs.
