摘要
目的 探讨高压氧预处理诱导脊髓缺血耐受的机制 .方法 2 1只雄性新西兰大白兔 ,随机分为 3组 (每组 n=7) :对照组 ,即常压空气组 ; HBO组 ,即单纯高压氧 (HBO)预处理组 (1 0 0 %O2 , 2 53 . 3 k Pa, 1 h· d- 1 , 5d) ; DMTU组 , HBO预处理条件同 HBO组 ,但于每次 HBO处理前 1 h予 50 0 mg· kg- 1 二甲基硫脲 (DMTU) iv.最后一次 HBO处理后 2 4h采用肾下主动脉阻断法造成脊髓缺血 (2 0 min) ,观察再灌注后 48h时的神经功能评分 ,及脊髓 (L5)病理学变化 .并同时测定后两组动物在 HBO预处理前 2 4h,每次 HBO处理后 1h,脊髓缺血前 1 0 min和再灌注 1 0 min时的血中丙二醛(MDA)水平 .结果 再灌注 48h时神经功能评分 HBO组明显优于对照组和 DMTU组 (P< 0 . 0 5) ;脊髓前角正常运动神经元计数明显多于对照组和 DMTU组 (P<0 . 0 5) . MDA水平各时间点两组间无显著差别 .结论 高压氧预处理所诱导的脊髓缺血耐受的机制与氧自由基的产生有关 .
AIM To investigate the mechanism of hyperbaric oxygen (HBO) preconditioning induced ischemic tolerance in spinal cord. METHODS 21 male New Zealand white rabbits were randomly allocated to one of 3 groups (7 in each group): animals in control group received room air and normal ambient pressure (1 h·d -1 , 5 d); animals in HBO group received HBO pretreatment (100% O 2, 253.3 kPa, 1 h·d -1 , 5 d); DMTU group, animals received HBO pretreatment (100% O 2, 253.3 kPa, 1 h·d -1 , 5 d), but 500 mg·kg -1 dimethylthiourea (DMTU) was administered iv. 1 h before each HBO pretreatment. At 24 h after the last HBO pretreatment, the spinal cord ischemia was induced for 20 min by infrarenal aortic occlusion. At 48 h after reperfusion, the neurologic status was scored by the Tarlov criteria (in which 4 was normal and 0 was paraplegia). All the animals were sacrificed at 48 h after reperfusion and their spinal cords (L 5) were removed immediately for histopathologic examination. The malondialdehyde (MDA) levels in the animals of HBO and DMTU groups were measured at 24 h before HBO pretreatment, 1 h after each HBO treatment, 10 min before spinal cord ischemia and 10 min after reperfusion. RESULTS The neurologic function scores in HBO group were higher than that in Control and DMTU groups ( P <0.05) at 48 h after reperfusion. The number of normal motor neurons in the anterior spinal cord in HBO group was more than that in Control and DMTU groups ( P <0.05). There was no obvious change in MDA levels among different time points and between HBO and DMTU groups. CONCLUSION The mechanism of hyperbaric oxygen preconditioning induced ischemic tolerance in the spinal cord of rabbits might be related to the production of oxygen free radicals by HBO pretreatment.
出处
《第四军医大学学报》
北大核心
2001年第23期2166-2167,共2页
Journal of the Fourth Military Medical University
关键词
脊髓缺血
再灌注损伤
自由基
缺血耐受
高压氧预处理
hyperbaric oxygenation
spinal cord
ischemia reperfusion injury
free radicals
ischemic tolerance
