黄体酮对大鼠面神经损伤轴突再生影响实验研究

Experimental Study of Progesterone on the Regeneration of Facial Nerve Axons in Rats

为探讨黄体酮在大鼠面神经损伤再生修复中的作用,将48只雌性Wistar大鼠先切除双侧卵巢,2周后建立单侧面神经钳夹损伤动物模型.大鼠随机分为两组.A组为黄体酮组(实验组),术后每日臀部肌注黄体酮注射液0.2mL;B组为对照组,术后每日注射等量的二甲基亚砜.1)分别在损伤后7、14、28d时各组取面神经损伤处的远端经丽春红G-亮绿SF染色法光镜下观察,计算横断面单位面积的有髓神经纤维数目及髓鞘厚度,透射电镜下观察神经纤维超微结构变化;2)术后7、14、21、28d时取大鼠损伤远端面神经行NGF(nerve growth factor,NGF)蛋白免疫组织化学染色,观察NGF的表达情况.结果显示,有髓神经纤维计数及髓鞘厚度在术后各时间点实验组均多于对照组,两者差异有统计学意义(P<0.05).NGF的表达在术后7、21、28d时实验组多于对照组,但在术后14d时两组差异无统计学意义(P>0.05).提示黄体酮促进面神经再生与其促进神经营养因子表达或运输有关.

To investigate the role of progesterone on the regeneration of facial nerve crush injury, 48 female Wistar rats were first performed ovariectomy. Two weeks later,the fight facial nerves of the rats were exposed and clamped with a smooth clamp to make a crash injury area of 2 mm. Then,all rats were randomized into two groups. Rats in group A （Experimental group） had hip intramuscular administration of progesterone injection （0.2 mL/d） while those in group B （Control group） had hip intramuscular administration of dimethyl sulfoxide （0.2 mL/d）. 1 ） The proximodistal injured facial nerve were determined with ponceau G - Brilliant green SF staining and observed under light microscope at days 7,14, 28 after surgery. Numbers of mean nerve fiber i,l unit area of transverse plane and the thickness of the myelin were calculated. Ultrastructure of nerve fiber were determined under transmission electron microscope; 2） At days 7,14,21,28 after surgery,the facial nerve stump immediately distal to the crushed site were harvested and then the expression of NGF were evaluated by using immunohistochemistry staining. The results showed that the myelinated nerve fiber numbers and the thickness of the myelin in group A at different intervals were significantly higher than those in group B,the expressions of NGF in group A were significantly better than those in group B at 7, 21,28 days. But there were no significant difference between the two groups at 14 days. It is suggested that the progesterone can facilitate facial nerve regeneration in that it promotes the expression or transportation of neurotrophic factors.