CAJ | 학술논문

本研究旨在探讨并比较慢性间歇性低压低氧(intermittent hypobaric hypoxia,IHH)~H慢性连续性低压低氧(continuous hy-pobaric 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),28天IHH处理纽(IHH28),42天IHH处理组(IHH42),28大CHH组(CHH28)和42大CHH组(CHH42).IHH大鼠十低压氧舱分别接受28或42天模拟5 000 m海拔高度低氧(11.1% O2)处理、每天6 h.CHH处理人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42天的模拟5 000 m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)、正负左窜最大压力变化速率(maximum change rate of left ventricular pressure,±LvdP/dtmax).通过生物化学方法测定人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(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±LVdp/dtmax改变明显低于CON大鼠(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±LVdP/dtmax 改变明显低于CON和IHH大鼠(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人鼠(P<0.05).(3)与CON人鼠相比较,IHH和CHH大鼠心肌抗氧化能力明显增强(P<0.05,P<0.01).(4)与IHH和CON大鼠相比较,CHH人鼠表现明显的右心室肥厚(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.
본연구지재탐토병비교만성간헐성저압저양(intermittent hypobaric hypoxia,IHH)~H만성련속성저압저양(continuous hy-pobaric hypoxia,CHH)대대서혈액동역학작용적영향.40지성년Sprague-Dawley대서수궤분위5조:대조조(CON),28천IHH처리뉴(IHH28),42천IHH처리조(IHH42),28대CHH조(CHH28)화42대CHH조(CHH42).IHH대서십저압양창분별접수28혹42천모의5 000 m해발고도저양(11.1% O2)처리、매천6 h.CHH처리인서생활재저압양창배경중,제매천반소시상양공식、공수화청길외,기여시간균분별접수시정위28혹42천적모의5 000 m해발고도저양(11.1% O2)처리.매주정시측정대서체중.통과도관법측정기출상양화급성저양상태하적혈액동역학,포괄평균동맥압(mean artery blood pressure,MAP)、심솔(heart rate,HR)、좌실수축봉압(left ventricular systolic pressure,LVSP)、정부좌찬최대압력변화속솔(maximum change rate of left ventricular pressure,±LvdP/dtmax).통과생물화학방법측정인서심기초양화물기화매활성화병이철함량.병분별측정전심、좌심실화우심실중량.결과현시:(1)CHH42대서기출HR화MAP저우CON,IHH화CHH28대서(P<0.05).(2)IHH대서표현출명현적항심기결양/복양손상작용,표현위급성저양상태하적HR、MAP、LVSP화±LVdp/dtmax개변명현저우CON대서(P<0.05):CHH대서표현출경위명현적항급성저양심장보호작용,표현위급성저양적HR、MAP、LVSP화±LVdP/dtmax 개변명현저우CON화IHH대서(P<0.05),단출현복양손상작용,표현위복양과정중혈액동역학적회복명현저우CON화IHH인서(P<0.05).(3)여CON인서상비교,IHH화CHH대서심기항양화능력명현증강(P<0.05,P<0.01).(4)여IHH화CON대서상비교,CHH인서표현명현적우심실비후(P<0.01).결과표명,IHH가유도유효적심장보호작용,이무명현적불량반응,인이구유잠재적실제응용개치.
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% O2)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/dtmax)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 wen measured by biochemical method.The weights of whole heart,left and fight 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/dtmax 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,LVSE and±LVdp/dtmax 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.