雌激素对脊髓损伤大鼠运动功能及GAP-43表达的影响

Effects of estrogen on motor function and GAP-43 expression in rats with spinal cord injury

目的探讨雌激素对脊髓损伤(SCI)大鼠运动功能和损伤区域生长相关蛋白-43(GAP-43)表达的影响。方法72只雄性SD大鼠按随机数表法分为假手术组(A组)、生理盐水模型组(B组)、雌激素组(C组),每组24只,B组、C组制作SCI模型,B组等量生理盐水腹腔注射,C组雌激素腹腔注射。术后3 d、1周、2周、3周检测BBB评分和Rivlin斜板试验。术后3 d、1周、2周、3周时间点处死大鼠取脊髓组织,行免疫组织染色观察GAP-43的表达情况。结果A组大鼠术后3 d、1周、2周、3周BBB评分分别为(20.48±0.57)分、(21.00±00)分、(21.00±00)分、(21.00±00)分,B组分别为(3.18±0.12)分、(4.28±0.15)分、(6.93±0.50)分、(8.95±0.34)分,C组分别为(3.27±0.15)分,(9.67±0.30)分、(14.06±0.69)分、(16.46±0.39)分,术后3 d、1周、2周、3周比较,A组明显高于B组和C组,C组术后1周、2周、3周明显高于B组,差异均有统计学意义(P<0.05);A组大鼠术后3 d、1周、2周、3周Rivlin斜板试验结果分别为(73.70±1.15)°、(75.00±0.00)°、(75.00±0.00)°、(75.00±0.00)°,B组分别为(22.98±0.98)°、(24.60±0.63)°、(27.58±0.79)°、(30.51±1.18)°,C组分别为(23.77±0.62)°、(29.83±0.66)°、(40.16±0.76)°、(49.00±1.48)°,术后3 d、1周、2周、3周比较,A组明显高于B组和C组,C组术后1周、2周、3周明显高于B组,差异均有统计学意义(P<0.05);术后3 d、1周、2周、3周,A组大鼠的GAP-43阳性细胞表达数分别为(2.20±0.66)个、(2.28±0.10)个、(2.31±0.17)个、(2.31±0.20)个,B组分别为(15.93±0.59)个、(26.45±0.69)个、(13.61±0.43)个、(4.59±0.47)个,C组分别为(23.38±0.40)个、(31.14±0.86)个、(18.78±0.37)个、(9.87±0.44)个,术后3 d、1周、2周、3周比较,B组和C组明显高于A组,C组明显高于B组,差异均有统计学意义(P<0.05)。结论雌激素能促进脊髓损伤大鼠的运动功能的恢复,其机制可能是通过增加脊髓损伤区域GAP-43的表达,促进神经的修复和再生。

Objective To investigate the effects of estrogen on motor function and the expression of growth-associated Protein 43(GAP-43)in the rats with spinal cord injury(SCI).Methods A total of 72 male SD rats were randomly divided into 3 groups,each with 24 rats:group A(sham group),group B(normal saline model group),group C(estrogen group).SCI models were made in groups B and C.The rats in group B were injected with the same amount of normal saline,and the rats in group C were injected with estrogen.BBB score and Rivlin inclined plate test were detected on the 3rd day,1st week,2nd week,and 3rd week after operation.The rats were sacrificed on the 3rd day,1st week,2nd week,and 3rd week after the operation and the spinal cord tissues were harvested for immunohistochemical staining to observe the expression of GAP-43.Results The BBB scores on the 3rd day,1st week,2nd week,3rd week after operation were(20.48±0.57)points,(21.00±00)points,(21.00±00)points,and(21.00±00)points in group A,respectively,(3.18±0.12)points,(4.28±0.15)points,(6.93±0.50)points,and(8.95±0.34)points in group B,and(3.27±0.15)points,(9.67±0.30)points,(14.06±0.69)points,and(16.46±0.39)points in group C.The BBB scores were significantly higher in group A than group B and group C on the 3rd day,1st week,2nd week,and 3rd week after surgery,and also significantly higher in group C than group B on the 1st week,2nd week and 3rd week,with statistically significant differences(P<0.05).In group A,the results of Rivlin inclined plate test on the 3rd day,1st week,2 nd week,and 3rd week after operation were(73.70±1.15)°,(75.00±0.00)°,(75.00±0.00)°,(75.00±0.00)°,respectively,(22.98±0.98)°,(24.60±0.63)°,(27.58±0.79)°,(30.51±1.18)°in group B,and(23.77±0.62)°,(29.83±0.66)°,(40.16±0.76)°,(49.00±1.48)°in group C;the results in group A were significantly higher than those in group B and group C on the 3rd day,1st week,2nd week,3rd week after the operation,and the results in group C were significantly higher than those in group B on the 1st week,2nd week,3rd week after the operation,with statistically significant differences(P<0.05).The expression numbers of GAP-43 positive cells of group A on the 3rd day,1st week,2nd week,3rd week after operation were 2.20±0.66,2.28±0.10,2.31±0.17,2.31±0.20,respectively,15.93±0.59,26.45±0.69,13.61±0.43,4.59±0.47 in group B,and 23.38±0.40,31.14±0.86,18.78±0.37,9.87±0.44 in group C;the numbers of group B and group C were significantly higher than those in group A on the 3rd day,1st week,2nd week,and 3rd week after surgery,and the numbers of group C were significantly higher than those in group B,with statistically significant differences(P<0.05).Conclusion The estrogen can promote the recovery of motor function in the rat spinal cord injury.It's mechanism is probably related to increasing the expression of GAP-43 in the area of SCI and promoting nerve repair and regeneration.