摘要
目的:观察中枢氧化应激对压力反射功能的影响,探讨自发性高血压大鼠(SHR)压力反射敏感性降低的中枢机制。方法:24周龄雄性SHR和正常大鼠在乌拉坦和α-氯醛糖混合麻醉下,静脉注射苯肾上腺素(PE)和硝普钠(NP)诱发动脉压力感受性反射,以心率变化与血压变化的比值代表压力反射敏感性(BRS)。侧脑室给予超氧化物歧化酶(SOD)拟似剂tempol和SOD抑制剂DETC,检测给药前后BRS变化。结果:高血压大鼠BRS明显低于正常大鼠(P<0.01),侧脑室应用Tempol明显改善高血压大鼠BRS(P<0.05),但不影响正常大鼠BRS;而DETC则衰减两组大鼠BRS(P<0.05),对正常大鼠BRS抑制作用更明显。高血压大鼠下丘脑丙二醛(MDA)含量明显高于正常大鼠(P<0.01),但总抗氧化能力、总SOD、CuZn-SOD、过氧化物酶(CAT)等活性均明显低于正常大鼠(P<0.05)。结论:高血压大鼠压力反射功能减弱与中枢氧化应激有关,脑内抗氧化酶活性降低和抗氧化能力下降可能导致中枢氧化应激。
Objective： To investigate the effects of central oxidative stress on the baroreflex function and central mechanism responsible for the attenuated baroreflex sensitivity（BRS） in spontaneously hypertensive rats（SHR）.Methods： Male 24-week-old SHR and normal rats were anesthetized with urethane and α-chloralose.Intravenous injection of phenylephrine（PE） and sodium nitroprusside（NP） evoked arterial baroreflex.The ratio of change in heart rate（HR） to change in mean aortic pressure（MAP） represented the baroreflex sensitivity（BRS）.Alteration in BRS was evaluated before and after intracerebroventricular administration of superoxide dismutase（SOD） mimetic tempol or SOD inhibitor diethyldithiocarbamic acid（DETC）.Results： BRS in hypertensive rats was significantly lower than that in normal rats（PE： P〈0.01,NP： P〈0.01）.Intracerebroventricular administration of Tempol significantly improved BRS in hypertensive rats（P〈0.05）,but not in normal rats.In contrast,DETC decreased BRS to a greater extent in normal group than in hypertension group（P〈0.05）.MDA content in hypothalamus of hypertensive rats was higher than that of normal rats（P〈0.01）,whereas total antioxidant capacity,total SOD,CuZn-SOD,catalase activity were lower in hypertensive rats than in normal rats（P〈0.05）.Conclusion： Attenuated baroreflex function in hypertensive rats is associated with central oxidative stress,which is linked to decreases in antioxidant enzyme activity and antioxidative capacity in the brain.
出处
《中国应用生理学杂志》
CAS
CSCD
2012年第5期445-448,共4页
Chinese Journal of Applied Physiology
基金
福建省教育厅资助项目(JA 09112)
福建医科大学教授基金课题(JS 10001)
关键词
高血压
压力反射敏感性
氧化应激
中枢神经系统
hypertension
baroreflex sensitivity
oxidative stress
central nevous system
