延髓腹外侧头端活性氧介导室旁核血管紧张素Ⅱ的交感兴奋作用  

Reactive oxygen species in rostral ventrolateral medulla mediate sympatho-excitation induced by AngⅡ in rats′ PVN

作　　者：钟明奎[1] 

机构地区：[1]安徽医科大学生理学教研室,安徽合肥230032

出　　处：《中国老年学杂志》2011年第11期2008-2011,共4页Chinese Journal of Gerontology

基　　金：国家自然科学基金资助项目(81070066);安徽省教育厅自然科学重点项目(KJ2010A176);安徽医科大学博士科研基金

摘　　要：目的探讨延髓腹外侧头端(RVLM)活性氧(ROS)是否介导室旁核(PVN)血管紧张素Ⅱ(AngⅡ)的交感兴奋作用。方法实验在去压力感受器神经支配和双侧迷走神经切断的麻醉大鼠上进行。采用立体定位仪进行核团定位微量注射,在体记录肾交感神经放电活动(RSNA)、平均动脉压(MAP)。结果 PVN内微量注射AngⅡ剂量依赖性地引起RSNA增强和MAP升高。应用超氧阴离子清除剂4-羟基-2,2,6,6-四甲基哌啶(Tempol)或内源性超氧化物歧化酶拟似物聚乙二醇-超氧化物歧化酶(PEG-SOD)清除RLVM内ROS对RSNA和MAP没有显著影响,但可抑制PVN内微量注射AngⅡ引起的交感兴奋作用。应用NAD(P)H氧化酶抑制剂夹竹桃麻素(Apocynin)或氧化酚砷(PAO)抑制RLVM内ROS的生成也可减弱AngⅡ的效应。结论 RLVM内NAD(P)H氧化酶来源的ROS介导了PVN内AngⅡ的交感兴奋作用。Objective To investigate whether reactive oxygen species（ROS） in rostral ventrolateral medulla（RVLM） mediate the increased sympathetic activity caused by microinjection of angiotensin Ⅱ（Ang Ⅱ in paraventricular nucleus（PVN）.Methods In anesthetized rats with sinoaortic denervation and cervical vagotomy,renal sympathetic nerve activity（RSNA）,mean arterial pressure（MAP） and heart rate（HR） were recorded in vivo on a PowerLab data acquisition system. The coordinates for PVN and RVLM were determined in a stereotaxic instrument according to Paxinos and Watson rat atlas.Results Bilateral PVN microinjection of angiotensin Ⅱ（Ang Ⅱ） increased the levels of RSNA and MAP in a dose-dependent manner.Bilateral RVLM microinjection of tempol（a superoxide anion scavenger） or polyethylene glycol-superoxide dismutase（PEG-SOD,an analogue of endogenous superoxide dismutase） did not cause significant change in baseline levels of RSNA and MAP;NAD（P）H oxidase inhibitors apocynin or phenylarsine oxide（PAO） also showed similar effects.The RSNA and MAP responses of Ang Ⅱ in PVN were inhibited by the pretreatment with RVLM administration of tempol,PEG-SOD,apocynin or PAO.Conclusions The enhanced sympathetic activity caused by Ang Ⅱ in PVN is mediated by NAD（P）H oxidase-derived ROS in RVLM.

关 键 词：血管紧张素Ⅱ 交感神经活动 室旁核 延髓腹外侧头端 活性氧 

分 类 号：R331.36[医药卫生—人体生理学]