过刊浏览

间歇性低压低氧与连续性低压低氧对大鼠血液动力学作用的比较

袁芳, 郭赞, 徐瑛, 王昕, 布会敏, 钟宁, 张翼, 周兆年

河北医科大学生理学教研室.河北,石家庄 050017；Gladstone Institutes of Cardiovascular and Neurological Diseases,University of California,San Francisco,CA94158

摘要

该研究旨在探讨并比较慢性间歇性低压低氧(intermittent hypobaric hypoxia,IHH)和慢性连续性低压低氧(continuous hypobaric hypoxia,CHH)对大鼠血液动力学作用的影响。40只成年Sprague--Dawley大鼠随机分为5组:对照组(CON),28d IHH处理组(IHH28),42d IHH处理组(IHH42),28dCHH组(CHH28)和42d CHH组(CHH42)。IHH大鼠于低压氧舱分别接受28或42d模拟5000m海拔高度低氧(11.1% O_(2))处理、每天6h。CHH处理大鼠生活在低压氧舱环境中,除每天半小时常氧供食、供水和清洁外,其余时间均分别接受时程为28或42d的模拟5000m海拔高度低氧(11.1%O2)处理。每周定时测定大鼠体重。通过导管法测定基础常氧和急性低氧状态下的血液动力学,包括平均动脉压(mean artery blood pressure,MAP)、心率(heart rate,HR)、左室收缩峰压(left ventricular systolic pressure,LVSP)、正负左室最大压力变化速率(maximum change rate of left ventricular pressure,±LVd{sl P}/d{sl t}_(max))。通过生物化学方法测定大鼠心肌超氧化物岐化酶活性和丙二醛含量。并分别测定全心、左心室和右心室重量。结果显示:(1)CHH42大鼠基础HR和MAP低于CON,IHH和CHH28大鼠({sl P}<0.05)。(2)IHH大鼠表现出明显的抗心肌缺氧/复氧损伤作用,表现为急性低氧状态下的HR、MAP、LVSP和±LVd{sl P}/d{sl t}_(max)改变明显低于CON大鼠({sl P}<0.05);CHH大鼠表现出更为明显的抗急性低氧心脏保护作用,表现为急性低氧的HR、MAP、LVSP和±LVd{sl P}/d{sl t}_(max)改变明显低于CON和IHH大鼠({sl P}<0.05),但出现复氧损伤作用,表现为复氧过程中血液动力学的恢复明显低于CON和IHH大鼠({sl P}<0.05)。(3)与CON大鼠相比较,IHH和CHH大鼠心肌抗氧化能力明显增强({sl P}<0.05,{sl P}<0.01)。(4)与IHH和CON大鼠相比较,CHH大鼠表现明显的右心室肥厚({sl P}<0.01)。结果表明,IHH可诱导有效的心脏保护作用,而无明显的不良反应,因而具有潜在的实际应用价值。

关键词： 间歇性低压低氧; 持续性低压低氧; 心脏保护; 血液动力学; 抗氧化作用; 大鼠

Comparison of the effects of chronic intermittent hypobaric hypoxia and continuous hypobaric hypoxia on hemodynamics in rats

Yuan Fang, Guo Zan, Xu Ying, Wang Xin, Bu Huimin, Zhong Ning, Zhang Yi, Zhou Zhaonian

Department of Physiology,Hebei Medical University.Shijiazhuang 050017,Hebei；USA；Shanghai Institutes for Biological Sciences,Chinese Academy of Sciences.Shanghai 200031

Abstract

The aim of this study is to investigate the effects of chronic intermittent hypobaric hypoxia(IHH) and chronic continuous hypobaric hypoxia(CHH) on hemodynamics under basic normoxia and acute hypoxia conditions and to find the difference of two types of chronic hypoxia.Forty adult male Sprague-Dawley(SD) rats were randomly divided into 5 groups:Control group(CON),28 days IHH group(IHH28),42 days IHH group(IHH42),28 days CHH group(CHH28) and 42 days CHH group(CHH42).The rats in IHH groups were treated with intermittent hypoxia(11.1% O_(2)) mimicking 5 000 m altitude in a hypobaric chamber for 28 or 42 d,6 h a day,respectively.The rats in CHH groups lived in the hypobaric chamber with the same degree of hypoxia like IHH rats except half an hour in normoxia each day for feeding and cleaning.The body weight of rats was measured once a week.The parameters in hemodynamics,such as mean artery blood pressure(MAP),heart rate(HR),left ventricular systolic pressure(LVSP),maximum change rate of left ventricular pressure(±LVdP/dt_(max)) were recorded under basic normoxia and acute hypoxia conditions through catheterization technique.The superoxide dismutase(SOD) activity and malondialdehyde(MDA) content in myocardium of rats were measured by biochemical method.The weights of whole heart,left and right ventricles were measured separately.The results showed:(1) The basic HR and MAP in CHH42 rats were lower than those in CON,IHH and CHH28 rats(P<0.05).(2) IHH showed a cardioprotection against acute hypoxia and reoxygenation injury,manifested as the result that the changes of HR,MAP,LVSP,and ±LVdP/dt_(max) were smaller than those in CON rats during acute hypoxia and reoxygenation.CHH showed a rather strong cardioprotection during acute hypoxia,manifested as the result that the decreases of HR,MAP,LVSP,and ±LVdP/dt_(max) were much smaller,but it did damage during reoxygenation,manifested as the result that the recovery of hemodynamics was the worst among three groups(P<0.05).(3) The antioxygenation of heart was increased in both IHH and CHH rats compared with that in CON rats manifested by the increased SOD activity and decreased MDA content(P<0.05,P<0.01).(4) IHH had no effect on heart weight,but CHH rats showed an obvious right ventricular hypertrophy compared with CON and IHH animals(P<0.01).The result indicates that IHH can induce a more effective cardioprotection with no much side effect,which might have a potential value for practical use.

Key words: chronic intermittent hypobaric hypoxia;chronic continued hypobaric hypoxia;cardioprotection;hemodynamics;antioxygenation;Rat

收稿日期：　　录用日期：

通讯作者：　　E-mail:

引用本文：

袁芳, 郭赞, 徐瑛, 王昕, 布会敏, 钟宁, 张翼, 周兆年. 间歇性低压低氧与连续性低压低氧对大鼠血液动力学作用的比较[J]. 生理学报 2008; 60 (6): 687-694.

Yuan Fang, Guo Zan, Xu Ying, Wang Xin, Bu Huimin, Zhong Ning, Zhang Yi, Zhou Zhaonian. Comparison of the effects of chronic intermittent hypobaric hypoxia and continuous hypobaric hypoxia on hemodynamics in rats. Acta Physiol Sin 2008; 60 (6): 687-694 (in Chinese with English abstract).