外源性雄激素对实验性变态反应性脑脊髓炎的视神经形态功能的影响

Effect of oral testosterone on the function and morphology of optic nerve in experimental autoimmune encephalomyelitis

目的研究在实验变态反应性脑脊髓炎（EAE）中,口服雄激素对视神经形态和功能的影响。方法雌性Wistar大鼠被随机分为3组：正常组、未治疗对照组和雄激素组。未治疗对照组每天以安慰剂灌胃,雄激素组每天以0.25mg/kg甲睾酮灌胃。在第20天,未治疗对照组和雄激素组注射完全弗氏佐剂-豚鼠脊髓匀浆（CFA-GPSCH）,并辅以注射百日咳疫苗（BPV）诱导EAE模型。我们用光学显微镜和闪光视觉诱发电位（F-VEP）观察视神经形态和功能的变化。结果EAE鼠发病后出现尾及后肢无力、麻痹甚至死亡等临床症状。与未治疗对照组相比,雄激素组的EAE发病率和临床表现明显下降（p〈0.05）。EAE鼠N1、P和N2潜伏期明显延长,N1-P和P-N2振幅降低。与未治疗对照组相比,雄激素组的潜伏期明显缩短（p〈0.05）,振幅升高（p〈0.05）。未治疗对照组视神经可见广泛的脱髓鞘,而雄激素组脱髓鞘不明显。结论口服雄激素对EAE鼠视神经有保护作用。

Objective Considering that sex steroids could influence the immune system, we observed the effect of oral testosterone on the function and morphology of optic nerve in experimental autoimmune encephalomyelitis （EAE）. Methods Female Wistar rats were randomly divided into 3 groups： the normal group; the testosterone group fed with 0.25mg/kg methyltestosterone orally per day; the untreated control group fed with placebo. On the 20thday, the untreated control group and the testosterone group rats were induced to establish EAE model by injecting guinea pig spinal cord homogenate （GPSCH） in complete Freund＇s adjuvant （CFA） and bordetella pertussis vaccine （BPV）. We observed the functional and morphological changes of optic nerve with the aid of flare-visual evoked potential and light microscope. Results EAE rats presented weakness or paralysis of tail and hind limb. Compared to the untreated control group, oral testosterone reduced the incidence of EAE and released signs. As to EAE rats the latency of N1, P and N2 wave had a marked prolongation, and the N1-P and P-N2 amplitude decreased. In the testosterone group, the latency was shorter than that of the untreated control group （p〈0.05）, and the amplitude increased（p〈0.05）.The results of light microscope showed extensive demyelination of optic nerve in the untreated control group, while demyelination of optic nerve in the testosterone group was not obvious. Conclusions Oral testosterone might protect optic nerve in Experimental Autoimmune Encephalomyelitis.