痉挛型瘫痪大鼠骨骼肌肌球蛋白重链亚型的蛋白表达研究

Expression of myosin heavy chain in skeletal muscle in rats with spastic paralysis

目的:探讨痉挛型瘫痪大鼠骨骼肌肌球蛋白重链亚型的蛋白水平。方法:将50只5d龄新生Sprague-Dawley大鼠随机分成假手术组和模型组,每组25只。建模后大鼠20日龄时,HE染色观察锥体束病理损伤情况,Western blotting检测瘫痪侧比目鱼肌和腓肠肌中MHC-Ⅰ、MHC-Ⅱb蛋白的表达。结果:与假手术组相比,模型组大鼠患侧肢体屈曲痉挛、走路缓慢、跛行,HE染色显示仅锥体束处出现细胞坏死、核固缩;模型组比目鱼肌MHC-Ⅰ蛋白表达(3.78±0.32)显著高于假手术组(0.24±0.11),P<0.001;模型组腓肠肌MHC-Ⅰ蛋白表达(3.68±0.28)显著高于假手术组(2.34±0.26),P<0.001;模型组比目鱼肌MHC-Ⅱb蛋白表达(0.34±0.16)显著低于假手术组(0.77±0.21),P<0.001;模型组腓肠肌MHC-Ⅱb蛋白表达(0.32±0.18)显著低于假手术组(0.78±0.22),P<0.001。结论:痉挛状态下大鼠骨骼肌肌球蛋白重链亚型MHC-Ⅰ蛋白高表达、MHC-Ⅱb蛋白低表达。

Objective: To investigate the protein level of myosin heavy chain subtype in skeletal muscle of spasmodic paralytic rats Method: Fifty Sprague-Dawley rats aged 5 days were randomly divided into sham operation group and model group, with 25 rats in each group. After the modeling, when the rats were 20 days, HE staining was used to observe the pathological damage at the pyramidal tract. Western blotting was used to detect the expression of MHC-Ⅰand MHC-Ⅱb proteins in the paralyzed flounder muscle and gastrocnemius muscle.Result: Compared with the sham group, the rats in the model group suffered from lateral limb flexion spasm,slow walking and claudication. The expression of MHC-Ⅰprotein was significantly higher in the model group than in the sham group(0.24±0.11)(P<0.001). MHC-Ⅰ protein expression in the model group was significantly higher than that in the sham group(2.34 ± 0.26)(P<0.001). The expression of MHC-Ⅱ b protein in the soleus muscle of the model group(0.34±0.16) was significantly lower than that of the sham group(0.77±0.21)(P<0.001). The expression of MHC-Ⅱb protein in the model group was significantly lower than that in the sham group(0.78±0.22)(P<0.001).Conclusion: Skeletal muscle myosin heavy chain subtype MHC-Ⅰ protein was highly expressed and MHC-Ⅱb protein was lowly expressed in rats with spastic paralysis.