阿米替林对SNI模型大鼠抑郁样行为及杏仁体外侧核5-HT2CRmRNA表达的影响

Effect of amitriptyline on depression and 5-HT_(2C) receptor expression in the SNI rat model

目的研究阿米替林(AMI)对神经病理性疼痛(NP)大鼠产生的抑郁样行为以及杏仁体外侧核(BLA)5羟色胺2C受体(5-HT2CR)mRNA表达水平的影响。方法将24只雄性Wistar大鼠随机分到3个组,分别为假手术组(S0组)、神经病理性疼痛组(NP组)和阿米替林组(AMI组),每组8只。采用坐骨神经分支保留性损伤(SNI)的方法制备神经病理性疼痛模型,AMI组大鼠在术后第14~35天每天腹腔注射阿米替林(10mg/kg)。术后第3,7,14,21,28,35天测各组大鼠右后足机械痛阈,计算50%缩足阈值(50%PWT)。术后第36天强迫游泳实验评价大鼠抑郁样行为,随后处死大鼠,用反转录PCR(RT-PCR)方法检测大鼠BLA脑区5-HT2CR mRNA的表达水平。结果与SO组比较,NP组50%PWT降低,强迫游泳静止时间延长,5-HT2CR mRNA的表达水平升高;与NP组比较,AMI组50%PWT升高,强迫游泳静止时间缩短,5-HT2CR mRNA的表达水平降低。结论阿米替林可改善神经病理性疼痛及其引起的抑郁样行为并降低BLA脑区的5-HT2CR mRNA的表达水平。

Objective To investigate the effects of amitriptyline（AMI） on depression in neuropathic pain（NP） rats and the expression of 5-HT2CR mRNA in the basolateral nucleus of the amygdale（BLA）. Methods Twentyfour male Wistar rats were randomly divided into three groups： sham operation group（S0 group）,neuropathic pain group（NP group） and amitriptyline group（AMI group）,with 8 rats in each group. The model of neuropathic pain was established by the method of spared nerve injury（SNI）. The rats in AMI group were treated with amitriptyline（10 mg·kg^-1·d^-1） intraperitoneally at 14 - 35 days after operation. On the 3 rd,7 th,14 th,21 st,28 th and 35 th day after operation,mechanical pain threshold was measured and the 50% paw withdrawal threshold（50% PWT） was calculated. The forced swimming test was performed on the 36 th day and the depressive state in rats was evaluated. Then the rats were sacrificed and the expression level of 5-HT2CR mRNA in BLA brain regions by reverse transcription-PCR（RT-PCR） was detected.Results Compared with the SO group,50% PWT in NP group decreased,forced swimming time was prolonged,and the expression of 5-HT2CR mRNA increased. Compared with NP group,50% PWT in AMI group increased,swimming time in forced swimming group was shorter,5-HT2CR mRNA expression decreased. Conclusion Amitriptyline improves neuropathic pain and the depression induced by it,as well as decreases the expression of 5-HT2CR mRNA in BLA brain regions.