背根神经节Kv7.2在吗啡减轻紫杉醇诱发大鼠神经病理性痛中的作用
Role of Kv7.2 in dorsal root ganglion in reduction of paclitaxel-induced neuropathic pain by mor-phine in rats
周颖 1姚梦夏 1王英 1郑辉哲 1詹美香1
作者信息
- 1. 福建医科大学肿瘤临床医学院 福建省肿瘤医院麻醉科,福州 350000
- 折叠
摘要
目的 评价背根神经节(DRG)Kv7.2在吗啡减轻紫杉醇诱发大鼠神经病理性痛(NPP)中的作用.方法 选择SPF级健康雄性SD大鼠,5周龄,体质量140～160 g.实验Ⅰ 取72只大鼠,采用随机数字表法分为4组(n=18):对照组(C组)、对照+吗啡组(C+M组)、NPP1组和NPP1+吗啡组(NPP1+M组).实验Ⅱ取24只大鼠,采用随机数字表法分为4组(n=6):NPP2组、NPP2+ML252 组、NPP2+吗啡组(NPP2+M 组)和 NPP2+吗啡+ML252 组(NPP2+M+ML252 组).腹腔注射紫杉醇溶液2 mg/kg,每2 d注射1次,共注射4次,构建NPP模型.模型构建完成后,C+M组、NPP1+M 组、NPP2+M 组和 NPP2+M+ML252 组皮下注射吗啡 5 mg/kg,NPP2+ML252 组和 NPP2+M+ML252组腹腔注射钾离子通道抑制剂ML252 10 mg/kg,连续注射7 d.实验Ⅰ各组分别于连续给药结束后第1、3和7天,实验Ⅱ各组于连续给药结束后第7天,随机取6只大鼠,测定机械缩足反应阈(MWT)和冷缩足潜伏期(CWL).行为学评估结束后,处死大鼠取DRG,采用Western blot法检测Kv7.2表达.实验Ⅰ于连续给药结束后第1天时,采用RT-qPCR法检测DRG Kv7.2 mRNA表达,免疫荧光法测定DRG Kv7.2表达和C组Kv7.2与神经元和胶质细胞的共表达情况.结果 实验Ⅰ与C组比较,C+M组各时点MWT升高,DRG Kv7.2及其mRNA表达上调(P＜0.05),CWL差异无统计学意义(P＞0.05),NPP1组各时点MWT降低,CWL缩短,DRG Kv7.2及其mRNA表达下调(P＜0.05);与NPP1组比较,NPP1+M组各时点MWT升高,CWL延长,DRG Kv7.2及其mRNA表达上调(P＜0.05).大鼠DRG Kv7.2在肽能中小直径神经元、非肽能中小直径神经元和大直径神经元中存在表达,在胶质细胞中不存在表达.实验Ⅱ 与NPP2组比较,NPP2+ML252组MWT、CWL和DRG Kv7.2表达差异无统计学意义(P＞0.05),NPP2+M组MWT升高,CWL延长,DRG Kv7.2表达上调(P＜0.05);与 NPP2+M 组比较,NPP2+M+ML252 组 MWT 降低,CWL 缩短,DRG Kv7.2 表达下调(P＜0.05).结论 DRG Kv7.2表达下调参与了吗啡减轻紫杉醇诱发大鼠NPP的过程.
Abstract
Objective To evaluate the role of Kv7.2 in the dorsal root ganglion(DRG)in reduction of paclitaxel-induced neuropathic pain(NPP)by morphine in rats.Methods SPF healthy male Sprague-Dawley rats,aged 5 weeks,weighing 140-160 g,were randomly selected.This experiment was performed in two parts.Experiment Ⅰ Seventy-two rats were divided into control group(group C),control+morphine group(group C+M),NPP-1 group(group NPP1)and NPP-1+morphine group(group NPP1+M),with 18 animals in each group.Experiment Ⅱ Twenty-four rats were divided into NPP2 group,NPP2+ML252 group,NPP2+morphine group(NPP2+M group),and NPP2+morphine+ML252 group(NPP2+M+ML252 group),with 6 animals in each group.The model of NPP was developed by intraperitoneal injection of paclita-xel 2 mg/kg,once every 2 days for 4 times.After preparation of the model,morphine 5 mg/kg was subcutane-ously injected in C+M group,NPP1+M group,NPP2+M group and NPP2+M+ML252 group,and potassium channel inhibitor ML252 10 mg/kg was intraperitoneally injected for 7 consecutive days in NPP2+ML252 group and NPP2+M+ML252 group.Six rats were randomly selected from each group on the 1st,3rd and 7th days af-ter the end of continuous administration in experiment Ⅰ and from each group on the 7th day after the end of continuous administration in experiment Ⅱ for measurement of the mechanical paw withdrawal threshold(MWT)and cold paw withdrawal latency(CWL).At the end of the behavioral assessment,the rats were sac-rificed and the DRG was removed for determination of Kv7.2 expression by Western blot.On the 1st day after the end of continuous administration in experiment Ⅰ,the expression of Kv7.2 mRNA in DRG was detected using quantitative real-time polymerase chain reaction,and immunofluorescence was used to detect the co-ex-pression of Kv7.2 with neurons and glial cells in group C.Results Experiment Ⅰ Compared with C group,the MWT was significantly increased,the expression of Kv7.2 protein and mRNA was up-regulated at each time point(P＜0.05),and no significant change was found in the CWL in C+M group(P＞0.05),and the MWT was significantly decreased,the CWL was shortened,and the expression of Kv7.2 protein and mRNA was down-regulated at each time point in NPP1 group(P＜0.05).Compared with NPP1 group,the MWT was significantly increased,the CWL was prolonged,and the expression of Kv7.2 protein and mRNA was up-regu-lated at each time point in NPP1+M group(P＜0.05).Kv7.2 in DRG was expressed in peptideergic small and medium diameter neurons,non-peptideergic small and medium diameter neurons and large diameter neurons,but not in glial cells.Experiment Ⅱ Compared with NPP2 group,no significant change was found in the expres-sion of MWT,CWL and Kv7.2 in NPP2+ML252 group(P＞0.05),and the MWT was significantly increased,CWL was prolonged,and the expression of Kv7.2 in DRG was up-regulated in NPP2+M group(P＜0.05).Com-pared with NPP2+M group,the MWT was significantly decreased,CWL was shortened,and the expression of Kv7.2 in DRG was down-regulated in NPP2+M+ML252 group(P＜0.05).Conclusions Down-regulation of Kv7.2 expression in DRG is involved in the reduction of paclitaxel-induced NPP by morphine in rats.
关键词
钾通道,电压门控/神经节,脊/吗啡/紫杉醇/神经痛Key words
Potassium channels,voltage-gated/Ganglia,spinal/Morphine/Taxol/Neuralgia引用本文复制引用
基金项目
福建省自然科学基金(2021J01434)
出版年
2024
NETL
NSTL
万方数据