氧疗对模拟急性高原缺氧兔超氧化物酶及丙二醛的影响

Effect of oxygen therapy on SOD and MDA of rabbits exposed to mimic acute hypoxia

目的探讨氧疗对模拟急性高原缺氧兔血清超氧化物酶（SOD）和丙二醛（MDA）的影响。方法建立急性高原缺氧兔模型，将28只新西兰大白兔分为5组，A组（5只）为正常对照组，B—E组置于低压舱内，B（7只）、C（5只）、D（5只）组分别给予体积百分比为25％、30％、35％的氧氮混合气持续吸入10，5，3h，E组（6只）直接暴露于低压舱内，于到达模拟海拔4500m高原开始氧疗后1，3，5，10，24h取标本，采用黄嘌呤氧化酶法和硫代巴比妥酸法分别检测血清中的SOD和MDA含量。结果与正常对照组相比，E组SOD活性下降及MDA含量增加最为显著；24h后B组SOD活性最高、MDA含量最低，C组次之，D组最差。B组SOD活性呈上升趋势，而MDA含量呈下降趋势。结论低浓度氧疗可在一定程度上减轻急性高原缺氧所致的细胞损伤，其机制除与提高氧分压有关外，还可能与平衡氧自由基代谢有关。

Objective To observe the changes of SOD and MDA after the rabbits were exposed to acute hypoxia when cured by oxygen therapy. Methods New Zealand rabbits underwent hypoxia imitating the 4500-meter sea level in altitude chamber （group E,n=6）, then some received oxygen therapy, the volume ratio of oxygen- nitrogen mixture was 25%, 30% and 35% respectively for 10, 5 and 3 hours as group B,C and D. Another 5 rabbits received no treatment as normal group. The rabbits samples were collected at the time points of 1,3,5,10 and 24 hours after the oxygen therapy started to detect serum biochemical indicators. Results Comparing with normal control group, serum SOD activity in simple hypoxia group noticeably decreased and the content of MDA noticeably increased; in three oxygen therapy groups, serum SOD activity in 25% oxygen therapy group was highest and the content of MDA was lowest. Serum SOD activity in 25% oxygen therapy group had ascendant tendency and the content of MDA had descendant tendency. Conclusions low concentration oxygen therapy can prevent acute hypoxia-induced injury in rabbits, besides increase oxygen partial pressure, oxygen therapy may improve superoxide dismutase activity.