重症肌无力被动转移大鼠模型眼外肌的易感机制研究  

Susceptible mechanisms of extraocular muscles in the passive transferred experimental myasthenia gravis rats

作　　者：刘睿[1] 王桂平[2] 杜婴[1] 周琼[1] 苗建亭[1] 李柱一[1] 

机构地区：[1]陕西省西安市第四军医大学唐都医院神经内科,710038 [2]吉林省长春市中国人民解放军第208医院神经外科,130062

出　　处：《中国神经免疫学和神经病学杂志》2012年第3期200-205,210,共7页Chinese Journal of Neuroimmunology and Neurology

基　　金：国家自然科学基金资助项目(30270485);陕西省自然科学基金资助项目(2010JQ4014)

摘　　要：目的探讨眼外肌在重症肌无力发病过程中的易感机制。方法给予SD大鼠腹腔注射mAb35建立重症肌无力被动转移(PTMG)大鼠模型,对照组大鼠注射等量生理盐水。选取PTMG组和对照组大鼠眼外肌、膈肌、胫前肌3种骨骼肌组织。采用乙酰胆碱酯酶(AChE)染色法观察神经肌肉接头(NMJ)并检测NMJ面积和灰度;采用银环蛇毒免疫组化法检测乙酰胆碱受体(AChR)数量;采用电镜观察NMJ超微结构和其AChR情况,并分析比较神经末端面积和突触后膜面积的比值以及突触前后膜长度的比值。结果 AChE染色结果显示,对照组眼外肌NMJ面积相对其他两种骨骼肌更小(P<0.01),PTMG组眼外肌与其他两种骨骼肌NMJ面积比较无统计学差异(P>0.05)。银环蛇毒免疫组化结果显示,PTMG组和对照组眼外肌与其它两种骨骼肌间AChR灰度值比较均有统计学差异(P<0.01)。电镜观察结果显示,PTMG组3种骨骼肌突触前后膜长度比值均较对照组下降(P<0.01),神经末端面积与突触后膜面积比值较对照组增加(P<0.01),其中眼外肌的变化较其他骨骼肌更为显著。结论 PTMG大鼠模型眼外肌易感机制可能与眼外肌和其他骨骼肌间NMJ面积、AChR数量差异造成眼外肌NMJ安全系数较低有关。Objective To investigate the susceptible mechanisms of extraocular muscles in passive transferred experimental myasthenia gravis （PTMG） rats. Methods PTMG model was induced by intraperitoneally injection of purified monoclonal antibody 35. The control group were intraperitoneally injected with normal saline. The extraocular muscles, diaphragms and tibial front muscles in the PTMG group and control group were dissected. Acetylcholinesterase staining, which showed neuromuscular junctions, and alpha bungarotoxin immunohistochemical reaction, which showed acetylcholine receptors （AChR） were used. Neuromuscular junction （NMJ） ultrastructure was observed by transmission electron microscope, and the ratios of pre/post synaptic membrane and acreaqe were analyzed. Results The aceaqe of NMJs in extraocular muscles in the PTMG group was comparable with other skeletal muscles （P〉0. 05）, but it was decreased in the control group in comparison with other skeletal muscles （P〈0.01）. There was significant difference in the gray value of AChRs among extraocular muscle and other skeletal muscles in both PTMG group and control group （P〈0.01）. Compared with the control group, the ratio of pre/post synaptic membrane decreased in all three kinds of skeletal muscles in the PTMG group （P〈0. 01）, and the ratio of pre/post synaptic acreaqe increased in all three kinds of skeletal muscles in PTMG group （P〈0. 01）, and the changes were more prominent in the extraocular muscles. Conclusions The susceptibility of extraocular muscles in PTMG rats were possibly related to the difference in NMJs aceaqe, NMJs amount among extraocular muscle and other skeletal muscles, which caused the relatively reduced safety factor in NMJs of extraocular muscles.

关 键 词：重症肌无力 眼外肌 神经肌肉接头 

分 类 号：R746.1[医药卫生—神经病学与精神病学]