阿米替林对神经病理性疼痛大鼠脊髓GLAST的影响

目的观察阿米替林对SNI大鼠脊髓谷氨酸-天冬氨酸转运体(GLAST)表达影响。方法60只♂SD大鼠,分为空白对照组(A)、SNI模型组(B)、阿米替林(AMI)注射对照组(C)、SNI模型+AMI治疗组(D),经腹腔分别给予0.2ml生理盐水(A、B)、10mg.kg-1AMI(C和D),每日两次。术后1、3、5d取各组大鼠L3~L6脊髓,分别检测GLAST的蛋白和mRNA表达改变,同时观察机械缩足反射阈值(mechanical withdrawal threshold,MWT)改变。结果与对照组相比,B组大鼠MWT随时间明显下降,GLAST蛋白和mRNA表达先增加再降低,C组大鼠MWT无改变,但是GLAST蛋白和mRNA表达随时间逐渐增加,D组大鼠MWT给药后3d停止下降,GLAST蛋白和mRNA表达明显增高,但不随时间变化。结论阿米替林可以增加GLAST蛋白表达,可能是治疗神经病理性疼痛的机制之一。

Influence of amitriptyline on GLAST in spinal cord of rat in neuropathic pain

Aim To investigate influence of amitriptyline on glutamate-aspartate transporter(GLAST)in spinal cord of rats after spared nerve injury.Methods 60 male SD rats were randomly divided into 4 groups with 15 rats in each:control(A),SNI(B),amitriptyline(C),SNI+amitriptyline(D).Respectively 4 groups were treated with intraperitoneal injections of 0.2 ml saline(A and B),10 mg·kg-1 amitriptyline(C and D),bid.The L3～L6 segments of the spinal cord were isolated in 1,3 and 5 days after surgery.Expression of GLAST was determined by western blot and semiquantitative RT-PCR.Also,changes of mechanical withdrawal threshold(MWT)were measured.Results Compared to control,a markedly decreased MWT was showed in group B and the expression of GLAST at both protein and mRNA level increased firstly and decreased later.There were no changes of MWT in group C,but the expression of GLAST increased gradually.Rat MWT in group D did not change any more at the third days after surgery.In addition,the expression of GLAST in group D was higher than control group and kept stable.Conclusions Amitriptyline could increase the expression of GLAST,which may be one of its mechanisms in the treatment of neuropathic pain.