骨化三醇对周围神经损伤后大鼠脊髓运动神经元的保护作用

Protective effect of calcitriol on spinal motor neuron after peripheral nerve injury

目的探讨骨化三醇[1，25（OH）2D3]对周围神经损伤后脊髓前角运动神经元的保护作用。方法48只SD大鼠随机分为安慰剂组和骨化三醇组，每组24只，切断右侧坐骨神经，近端结扎，远端埋人股二头肌。术后骨化三醇组给予骨化三醇2μg·kg^-1·d^-1灌胃，安慰剂组给予脂肪乳剂2ml·kg^-1·d^-1灌胃，灌胃7d。术后1、2、4周分别处死动物，取腰膨大（L4～L6节段）脊髓，分别行尼氏染色，胆碱酯酶（CHE）染色和酸性磷酸酶（ACP）染色，并结合计算机进行图像分析。结果术后1、2、4周，骨化三醇组脊髓前角运动神经元存活率分别为（90．8±3．5）％、（84．1±2．3）％、（76．2±2．7）％，高于安慰剂组[（84．3±6．5）％、（76．3±2．7）％、（73．4±1．9）％]（t=-5．442、-6．443、-2．286，P〈0．01或P〈0．05）；骨化三醇组脊髓CHE染色阳性面积百分率分别为（69．1±1．4）％、（74．5±3．4）％、（78．9±6．6）％，高于安慰剂组[（59．5±1．0）％、（65．8±4．0）％、（66．8±5．3）％]（t=-15．787、-10．781、-11．954，P〈0．01）；骨化三醇组脊髓ACP染色阳性面积百分率分别为（182．8±5．5）％、（115．0士12．5）％、（108．7±8．4）％，低于安慰剂组[（206．5±14．7）％、（138．2±9．9）％、（u5．1±9．0）％]，第1、2周t=4．275、4．113，P〈0．01；第4周t=1．458，P=0．167。结论骨化三醇对周围神经损伤所致的脊髓前角运动神经元损伤有一定的保护作用。

Objective To investigate the protective effect of calcitriol on anterior horn motor neuron of spinal cord after peripheral nerve injury. Methods A total of 48 SD rats （250-300 g body weight） were divided into 2 groups： control group and calcitriol intervention group （n = 24, respectively）. The right nervi ischiadicus of rats were cut off with proximal ligation, and the distal ends were embedded into biceps femoris. After surgery, rats were treated with equivalent fat milk （2 ml· kg^-1 · d^-1） in control group, lasting 7 days. And the rats were treated with calcitriol （2· kg^-1 · d^-1） in intervention group. Rats were killed at 1, 2 and 4 weeks. The specimens of L4-L6 spinal cord were taken and sectioned. The Nissl＇s, cholinesterase （CHE） and acid phosphatase （ACP） staining in motor neurons were executed and analyzed. Results At the same time point, the viabilities of spinal cord anterior horn motor neurons were higher in caicitriol intervention group than in control group [1 week： （90.8±3.5）% vs. （84.3±6.5）（t=-5.442,P〈0.01）%; 2 weeks： （84.1±2.3）% vs. （76.3±2.7）%（t=-6.443,P〈0.01）; 4 weeks： （76.2±2.7）% vs. （73.4± 1.9） %] （t=- 2. 286, P〈0.05）. The CHE activities were significantly higher in calcitriol intervention group than in control group [1 week： （69.1±1.4）% vs. （59.5±1.0）%（t=-15.787,P〈0.01）; 2 weeks： （74. 5±3.4）% vs. （65.8±4.0）%（t=-10.781,P〈0.01）; 4 weeks： （78.9±6.6）% vs. （66.8±5.3） %]（t=-11. 954,P〈0.01）, and the ACP activities were significantly lower in calcitriol intervention group than in control group [1 week： （182.8 ± 5.5）% vs. （206.5 ±14.7）% （t = 4. 275, P〈0.01）; 2 weeks： （115.0±12.5）% vs. （138.2±9.9）%（t=4.113,P〈0.01）; 4 weeks： （108.7 ±8.4）% vs. （115.1±9.0）%]（t=1. 458,P〈0.16）. Conclusions Calcitriol has protective effect on spinal motor neuron after peripheral nerve injury.