中文摘要：

目的观察大鼠脊髓损伤（SCI）前后痉挛腓肠肌（GM）的病理特征、超声弹性特征及两者的相关性。方法将24只SD雄性大鼠分为对照组（n=6）和SCI组（2、4、12周亚组,每组6只）。各组大鼠在上述各时间点完成踝关节肌张力改良Ashworth量表（MAS）评分、BBB运动功能评分、超声弹性成像评估GM硬度（Young＇s模量）、肌ATP酶染色及MyHC电泳分析。相关性采用Pearson相关分析。结果踝跖屈时,对照组GM的Young＇s模量与体质量呈正相关（r=0.89,P=0.02）,与MyHC-Ⅰ占比呈负相关（r=-0.83,P=0.04）;2周亚组GM的Young＇s模量与其MyHC-Ⅰ型肌纤维占比呈正相关（r=0.85,P=0.03）。踝背曲时,对照组GM的Young＇s模量与其Ⅰ型纤维占比呈负相关（r=-0.91,P=0.01）,4周亚组GM的Young＇s模量与体质量呈负相关（r=-0.92,P=0.01）。结论 SCI后大鼠GM的硬度特征与其早期病理改变相关;而后期发生的GM硬度改变可能与其肌纤维外结构改变有关。

英文摘要：

Objective To observe pathological characteristic and ultrasonic elastography characteristics of spastic gastrocnemius（GM）and the correlation between them in rat models before and after spinal cord injure（SCI）.Methods Totally24 SD male rats were divided into control group（n=6）and SCI model groups（2,4,12 week subgroup,each n=6）.At above different time points,the modified Ashworth scale（MAS）was used to assess the GM spasticity,Basso,Beattie,and Bresnahan locomotor rating scale（BBB scale）was used to assess the movement ability of lower limb for rats,GM stiffness was assessed with shear wave ultrasonic elastography technology in each group.The GM of rat would be forwarded for pathological examinations（ATP staining,myosin heavy chain electrophoretic）after ultrasonic elastography examinations in all groups.The correlation was analyzed by Pearson correlation analysis.Results During ankle plantar flexion,it was showed that Young＇s modulus of GM was significant positive correlation with weight of rats in control group（r=0.89,P=0.02）,significant negative correlation was found between Young＇s modulus of GM and ratio of MyHC-Ⅰ of GM in control group（r=-0.83,P=0.04）.Significant positive correlation was found between Young＇s modulus of GM and ratio of MyHC-Ⅰ of GM at 2^nd week（r=0.85,P=0.03）.During ankle dosiflexion,significant negative correlation was found between Young＇s modulus of GM and ratio of typeⅠfibers in control group（r=-0.91,P=0.01）,significant negative correlation was found between Young＇s modulus of GM with the weight of rats at 4^th week（r=-0.92,P=0.01）.Conclusion In SCI model,the stiffness of GM is correlation with pathological characteristics happened early,while it maybe be correlated with the changes of structures outside muscle fiber in later period.