The Experimental Study On The Effects Of Electro-Acupuncture (EA) On The Expression Of Glial Fibrillary Acidic Protein (GFAP) After Acute Spinal Cord Injury (SCI) In Rats

Objective:To illustrate the mechanism of the treatment of electro-acupuncture on spinal cord injured through showing the change of the expression of GFAP in spinal cord before and after the operation and treatment.Methods:60 adult Wistar rats were assigned randomly and averagely to the control group(A),the model group(B),and the treatment of EA group(C) and SCI model was duplicated by using modified Allen's method in that group B and C were received transectable SCI at the T₁₀ vertebrae level while the group A was just opened the vertebrae and their spinal cords were not wounded.The group C was treated by EA-Apparatus with serried consecutive wave,100Hz frequency and 9V voltage and the points were chosen in the interspaces of the Centrum between nine and ten and the interspaces of Centrum between ten and eleven,about 3-4mm aparted from the midline.Two groups of leads of EA-Apparatus were connected with the handle of EA,with the anode up and cathode below,and then turned on the button of EA-Apparatus with the deferent intensity of electrical current with appearing slight twitch of the back of muscle.The rats of group C were treated twice per day and it lasted 15 minutes per time.Finally,all spinal cords of the injured section were taken out in different time,such as on the third day,the seventh day,the fourteenth day and twenty-first day after the operation.Western Blot and immunohistochemical methods with optic microscope were used to examine the change of the expression of GFAP in these tissues and an open field locomotor scale(the Basso,Beanie and Bresnahan,BBB) was used to assess the outcome of locomotors performance in rats.Result:1.The result of the BBB shows:The third day after the spinal cord injured,the outcome of locomotors performance in rats in group C is superior to the group B and there is a distinct difference in statistics(P＜0.05) and the group C is highly superior to the group B with the drastic difference in statistics(P＜0.01) after the seventh day,but the scores of both of group B and group C are much lower than group A。2.The result of the immunohistochemical dye shows:after the treatment with EA on the rats of the spinal cord injured,the number of astrocytes of the group C is greatly lower than group B after three days and seven days and there is a distinct difference in statistics(P＜0.01),and the number of astrocytes of the group C is still lower than group B with the distinct difference in statistics(P＜0.05) after fourteen days,but after twenty-one days,the number of astrocytes of both groups is close and there is not distinct difference in statistics(P＞0.05)。3.The result of the Western Blot shows:there is expression of GFAP among group A,B and C and the trend of group B increases by degrees with the strongest expression after two weeks,and then it decreases gradually。The expression of GFAP of group B is distinctly higher than group A and group C。Conclusions:1.EA can inhibit the proliferation of astrocytes,which creates a beneficial environment for nerves to regenerate.And therefore it proved to be the effective treatment for the spinal cord injured.2.EA can help to promote the function recovering of the spinal cord injured and its mechanism might by restraining the expression of GFAP.3.The best time of regeneration on spinal cord injured might be within two weeks,and so it should be treated as early as possible.