高压氧间断暴露及氧惊厥对大鼠抗氧化酶活力及脂质过氧化物含量的影响

目的：为研究高压氧暴露对机体抗氧化酶系统的影响，本实验观察了高比氧间断暴露及氧惊厥条件下，大鼠红细胞、肺和肝组织中抗氧化酶（ＳＯＤ、ＧＳＨｐｘ、ＣＡＴ）活力及作为脂质过氧化物（ＬＰＯ）指标的丙二醛（ＭＤＡ）的含量的变化。方法：３８只雄性ＳＤ大鼠随机分组为：常压空气对照组（ｎ＝１２）；０．３ＭＰａＮ＿２－Ｏ＿２（ＰＯ＿２＝２１ｋＰａ）组（ｎ＝６）与０．３ＭＰａＯ＿２组（ｎ＝１２），暴露时间均为每天３０分钟，连续１０天；氧惊厥组（ｎ＝８）为０．６ＭＰａＯ＿２暴露１５分钟１次。结果：０．３ＭＰａＯ＿２，及０．３ＭＰａＮ＿２０Ｏ＿２两组组织中ＳＯＤ、ＧＳＨｐｘ、ＣＡＴ的活力及ＭＤＡ含量没有显著变化；０．６ＭＰａＯ＿２氧惊厥组，红细胞中ＧＳＨｐｘ活力与对照相比显著下降（Ｐ＜０．０５），而红细胞及肝组织中的ＭＤＡ含量则显著升高（Ｐ＜０．０５），但ＳＯＤ及ＣＡＴ活力无明显变化。结论：本实验中高压氧间断暴露方式对机体没有明显损害作用；氧中毒时ＧＳＨｐｘ活力易受抑制为抗氧化酶防御系统中的薄弱环节。

Effects of intermittent hyperbaric oxygen exposure and oxygen convulsions on antioxidant enzyme activ-ity and lipid peroxide contents in rats

Aim:In order to clarify the mechanism of change of antioxidant enzyme system under hy-perbaric oxygen exposure,the effects of intermittent hyperbaric oxygen exposure and oxygen convul-sions on antioxidant enzymes(SOD,GSHpx,CAT)activities and the levels of MDA (used as an indica-tor of LPO)were studied in rat tissues(RBC, lung,liver).Methods:38 male SD rats were randomly divided into 4 groups:normal pressure air control group(n=12);0. 3 MPa N2-O2(PO2=21 kPa,n= 6)and 0.3 MPa O2 groups(n=12),in which the rats were exposed accordingly 30 min daily for 10 d;and the oxygen convulsions group(exposed to 0.6 MPa O2 for 15 min).Results:The activities of antioxi-dant enzymes and contents of MDA were not changed in the 0.3 MPa O2 and 0.3 MPa N2-O2 groups.However,in the oxygen convulsions group, the activity of GSHpx in RBC was significantly inhibited(P<0. 05) and the MDA contents in RBC and liver tissue were markedly elevated(P<0.05); but the ac-tivities of SOD and CAT were not significantly changed.Conclusion:Intermittent exposure of 0. 3 MPa O2 for 10 d may do no harm to the body;whereas the GSHpx activities are prone to be inhibited in oxy-gen convulsions, which seems to be a weak point in the antioxidant enzyme system.