右美托咪定基于CD38/cADPR通路对罗哌卡因致惊厥大鼠大脑氧化应激的保护作用

The protective effect of dexmedetomidine based on CD38/cADPR pathway on oxidative stress in the brain of ropivacaine-induced convulsions in rats

目的观察右美托咪定是否经CD38/cADPR通路发挥抑制罗哌卡因致惊厥大鼠大脑氧化应激的作用。方法2020年1月—2021年1月于湖北省恩施土家族苗族自治州中心医院进行实验,选择SPF级雄性大鼠60只,随机数字表法选取20只作为空白对照组,其余40只大鼠腹腔注射0.5%罗哌卡因33.8 mg/kg制备惊厥模型,最终37只大鼠建模成功,随机数字表法分为模型组19只和右美托咪定组18只。右美托咪定组大鼠腹腔注射右美托咪定100μmol/L,空白对照组、模型组均腹腔注射等剂量生理盐水。测定各组大鼠学习记忆能力,比较各组大鼠脑组织病理变化、脑细胞凋亡率、脑组织氧化应激程度及脑组织CD38/cADPR通路蛋白表达量。结果与空白对照组比较,模型组大鼠学习能力下降,而与模型组比较,右美托咪定组学习能力提高(t/P=12.160/<0.001);空白对照组大鼠脑组织中神经细胞排列较为整齐,内含丰富的尼氏小体,染色均匀;神经细胞合成蛋白质功能较强。模型组大鼠脑组织神经细胞损伤较为严重,排列紊乱,尼氏小体着色较浅;右美托咪定组大鼠脑组织神经细胞形态较为完整,与模型组比较,尼氏小体数量增加,染色均匀。与空白对照组比较,模型组脑细胞凋亡率升高(P<0.05);与模型组比较,右美托咪定组脑细胞凋亡率降低(t/P=6.084/<0.001)。与空白对照组比较,模型组脑组织SOD含量减少,MDA含量增加(P<0.05);与模型组比较,右美托咪定组脑组织SOD含量增加,MDA含量减少(P<0.05)。与空白对照组比较,模型组脑组织CD38、cADPR、Bax、iNOS表达升高,Bcl-2、Caspase-3表达降低(P<0.05);与模型组比较,右美托咪定组脑组织CD38、cADPR、Bax、iNOS表达降低,Bcl-2、Caspase-3表达升高(P<0.05)。结论右美托咪定可能通过抑制CD38/cADPR通路活性,抑制大脑氧化应激反应、脑细胞凋亡,进而发挥保护罗哌卡因致惊厥大鼠的作用。

Objective To observe whether dexmedetomidine inhibits oxidative stress in the brain of ropivacaine-induced seizure rats via the CD38/cADPR pathway.Methods From January 2020 to January 2021,the experiment was carried out in the Department of Anesthesiology,Central Hospital of Enshi Tujia and Miao Autonomous Prefecture,Hubei Province.60 SPF male rats were selected,20 were selected as normal control group by random number table,and the remaining 40 rats The convulsive model was prepared by intraperitoneal injection of 0.5%ropivacaine 33.8 mg/kg.Finally,37 rats were successfully modeled.They were randomly divided into a model group of 19 rats and a dexmedetomidine group of 18 rats.Rats in the dexmedetomidine group were intraperitoneally injected with dexmedetomidine 100μmol/L,and the normal control group and model group were intraperitoneally injected with the same dose of normal saline.The learning and memory abilities of rats in each group were measured,and the pathological changes of brain tissue,the rate of brain cell apoptosis,the degree of brain oxidative stress and the expression of CD38/cADPR pathway protein in brain tissue were compared.Results Compared with the normal control group,the learning ability of rats in the model group decreased,while compared with the model group,the learning ability of the dexmedetomidine group increased(t/P=12.160/<0.001).The nerve cells in the brain tissues of the rats in the normal control group are arranged neatly,with abundant Nissl bodies and evenly stained.Nerve cells have strong function of synthesizing protein.In the model group,the nerve cells in the brain tissue of rats were more severely damaged,arranged disorderly,and the Nissl bodies were lightly colored.The morphology of nerve cells in the brain tissue of rats in the dexmedetomidine group was relatively complete.Compared with the model group,the number of Nissl bodies increased and the staining was even.Compared with the normal control group,the brain cell apoptosis rate of the model group increased(P<0.05).Compared with the model group,the brain cell apoptosis rate of the dexmedetomidine group was reduced(t/P=6.084/<0.001).Compared with the normal control group,the SOD content in the brain tissue of the model group decreased,and the MDA content increased(P<0.05).Compared with the model group,the SOD content in the brain tissue of the dexmedetomidine group increased,and the MDA content decreased(P<0.05).Compared with the normal control group,the expression of CD38,cADPR,Bax,iNOS in the brain tissue of the model group increased,and the expression of Bcl2 and Caspase3 decreased(P<0.05).Compared with the model group,the expression of CD38,cADPR,Bax,iNOS in the brain tissue of the dexmedetomidine group decreased,and the expression of Bcl2 and Caspase3 increased(P<0.05).Conclusion Dexmedetomidine may inhibit the oxidative stress response and brain cell apoptosis in the brain by inhibiting the activity of the CD38/cADPR pathway,thereby protecting the rats with ropivacaine-induced seizures.