电针对脊髓损伤星形胶质细胞增生及其NGF表达的影响

目的研究脊髓损伤后电针治疗对星形胶质细胞增生及其内源性神经生长因子(nerve growth factor,NGF)表达的影响.方法选用成年雌性Wistar大鼠,随机分为3组.A组为正常对照组,B组、C组为下胸段脊髓不完全损伤.B组损伤后不治疗,C组损伤后给予督脉电针治疗.损伤后3 d、1 、2或4周应用免疫组化染色分别观察损伤脊髓胶质原纤维酸性蛋白(glial fibroblast acid protein,GFAP)和NGF表达的变化.结果 B组术后3 d,GFAP阳性细胞明显增多, 2周后开始减少,4周时仍有较多的阳性细胞;C组GFAP阳性细胞明显少于B组,1周时达高峰.脊髓损伤后NGF表达呈逐渐增加的趋势.C组NGF的表达明显高于B组,且一直保持在较高水平.NGF阳性细胞大部分与GFAP阳性细胞形态相似.结论电针治疗能减少星形胶质细胞增生,促进内源性NGF的合成,从而创造了有利于神经再生的微环境.

EFFECTS OF ELECTRO-ACUPUNCTURE ON THE PROLIFERATION OF ASTROCYTES AND THE EXPRESSION OF ENDOGENOUS NGF IN INJURED SPINAL CORD

Objective To investigate the effects of electro-acupuncture on the proliferation of astrocytes and the expression of the endogenous nerve growth factor(NGF) after spinal cord injury(SCI). Methods Female adult Wistar rats were randomized into threegroups. GroupA was the normal control group, while group B and C were injured in the lower thoracic spinal cord by Allen's method. The rats in group B werenottreated at all, whereas those in group C were treated with electro-acupuncture on the DU Channel. The changes of GFAP and NGF were detected by using immunohistochemical staining on the 3rd day, 1st week , 2nd week and 4th week after the operation. Results The number of GFAP-positive cells on the 3rd day in group B was more than that in group A. It began to decrease by the 2nd week, and remained at a high level till the 4 th week. In group C it was less than that in group B, and the GFAP expression reached the highest levelin the 1st week. The expression of NGF in group B and C kept increasing during the test period. It was higher in group C than in group B, and remained at a high level till the end of the test. Most of the NGF-positive cells were morphologically similar to the GFAP-positive astrocytes. Conclusion Electro-acupuncture may inhibit the proliferation of astrocytes and enhance the expression of endogenous NGF after spinal cord injury, which creates a beneficial environment for nerves to regenerate.