二甲胺四环素对大鼠脊髓损伤后iNOS表达及细胞凋亡的影响

Effect of minocycline on expression of iNOS and apoptosis after spinal cord injury in rats

目的探讨大鼠脊髓损伤后应用二甲胺四环素(minocycline)对诱导型一氧化氮合酶(iNOS)表达及细胞凋亡的影响。方法成年大鼠随机分为脊髓损伤后应用二甲胺四环素的治疗组(A组)和应用生理盐水对照组(B组),损伤后不同时间点取材,用HE染色观察损伤脊髓组织病理变化;用免疫组化染色检测iN-OS的表达变化;原位末端标记法(TUNEL法)标记凋亡细胞;采用开放场地试验BBB评分和斜板试验,评价神经功能。结果HE染色镜检发现脊髓组织病理学改变A组明显轻于B组。A、B两组均发现凋亡细胞及iNOS表达,神经细胞凋亡指数及iNOS表达均为B组>A组(P<0.05)。治疗组神经功能改善优于B组。结论二甲胺四环素能抑制大鼠脊髓损伤后iNOS表达及细胞凋亡。

[Objective] To investigate the effect of minocycline on expression of iNOS and apoptosis after spinal cord injury （SCI） in rats. [Methods] Adult SD rats were divided at random into two groups： with pressure to cause spinal cord injury and use minocycline group （group A）, and use normal saline group （group B）. After operation the rats were sacrificed at 4 h, 8 h, 1 d, 3 d, 7 d, 14 d and 21 d after surgery, and then the tissue sections were stained with hematoxylin and eosin（HE）, immunohistochemistry and terminal deoxynucl-eotidyl transferase-mediated dUTP nick end labeling （TUNEL） method, and the injured spinal cord tissue was evaluated. [Results] The histopathology changes in spinal cord tissue observed with HE staining microscopic examination in group B was worse than that in group A. Expression of iNOS and apoptotic cells were observed in two groups, and the apoptotic index and expression of iNOS in group B was higher than that in group A （P 〈0.05）. [Conclusion] This study demonstrated that minocycline can inhibit expression of iNOS and apoptosis after SCI in rats.