高压氧预适应对大鼠减压病的预防作用研究

发布时间：2018-05-20 13:53

本文选题：高压氧 + 预适应　；参考：《第二军医大学》2010年硕士论文

【摘要】： 随着社会的发展,以海洋资源开发、考古探险或军事作业等目的的水下活动越来越普遍和频繁。人员进入水下,必须呼吸与周围水压相等的气体。呼吸气体中分压增高的惰性气体(指生理性惰性气体,最常见的是氮气),会随着潜水时间和深度的增加,而不断地溶解于机体组织中,这就要求随后的减压必须遵循一定的规则,否则惰性气体可能过快地溢出,在组织和血液中“就地”生成气泡,出现减压病(decompression sickness, DCS)。DCS可引起皮肤瘙痒、关节疼痛、呼吸循环障碍和神经系统损害的各类表现,严重者可以导致潜水员快速死亡。预防DCS成为水下作业安全保障的核心环节。高压氧(hyperbaric oxygen, HBO)是治疗DCS的主要手段。近年研究发现,HBO预适应能够有效预防多种缺血缺氧性损伤。DCS也具有缺血缺氧的病理生理特点,HBO预适应对DCS是否也具有预防保护作用呢? 本课题旨在观察HBO预适应对于大鼠DCS的预防效应并初步探讨其机制。研究共分两部分进行。第一部分,建立空气潜水减压病大鼠模型。以适当“压力-时程-减压速率”高气压暴露方案处理成年Sprague-Dawley (SD)大鼠,暴露结束后立即置于自行研制的电控转笼中,以3 m/min速度运动30 min。从整体行为学、大体及显微病理学、炎症反应等方面筛选建立评估指标体系。通过控制高气压暴露的“压力-时程-减压速率”以及转笼运动方法,可制备出具有稳定发病率的大鼠减压病模型,并能很好地观测大鼠行为学的变化；建立了包括行为学、肺及中枢神经系统大体病理和显微病理以及炎性指标在内的模型评估体系。第二部分,探讨HBO预适应对于大鼠DCS的预防效应及其机制。研究又分两部进行。 ①HBO预适应效应观察。成年SD大鼠以HBO(250 kPa-60min)处理(n=33),18 h后进行模拟空气潜水(700kPa-100min),快速减压(200 kPa/min)后动物在转笼中以3 m／min的速率运动30 min,观察DCS发病情况。对照动物分别以常压空气(n=30)或常氧高氮混合气(11=13)预处理。结果发现,HBO预处理组的发病率(30.3%)显著低于空气对照组(63.3%)(p0.05)；常氧高氮预处理对DCS发病率无显著影响(61.5%)。 ②HBO预适应机制研究,该部分又分为两步。第一,一氧化氮(nitric oxide, NO)在HBO预适应效应中的作用观察。检测了HBO暴露后即刻和18h大鼠大脑、脊髓和肺NO的含量；并观察了应用一氧化氮合酶(nitric oxide synthetase, NOS)抑制剂N-亚硝基-L-精氨酸甲酯(NG-Nitro-L-arginine Methyl Ester, L-NAME)对于HBO预防作用的影响。HBO暴露后即刻大鼠大脑、脊髓和肺NO含量显著升高(p0.05),L-NAME可抑制此效应；暴露后18h各组织中NO含量无显著变化。L-NAME可显著对抗HBO对DCS的预防作用,发病率又回升至71.4%(p0.05)。第二,热休克蛋白(heat shock protein, HSP) 70在HBO通过NO预防DCS中的作用观察。检测了HBO暴露后18 h大鼠大脑、脊髓和肺HSP70的表达,观察了L-NAME和HSP抑制剂槲皮素(Quercetin, Q)对于HBO诱导HSP70表达的影响以及Q对HBO预防作用的影响。HBO暴露后18 h,大鼠大脑、脊髓和肺HSP70表达显著增高,L-NAME和Q均可抑制HSP70的增高。Q可有效对抗HBO对DCS的预防作用,动物DCS发病率显著回升至69.2%(p0.05)。上述结果可得出以下结论： 1.18 h前的HBO预适应能够有效预防大鼠DCS的发生； 2.HBO通过NO诱导HSP70表达,进而发挥对DCS损伤的保护作用。
[Abstract]:With the development of society, underwater activities, such as marine resources development, archaeological exploration, or military operations, are becoming more and more common and frequent. Personnel entering the water must breathe the gas that is equal to the surrounding water pressure. The inert gas (the physiological inert gas, the most common nitrogen) in the breathing gas (the most common is the nitrogen) in the breathing gas, will follow the time of diving and the time of diving. The depth increases, and continues to dissolve in the body tissue, which requires that subsequent decompression must follow certain rules, otherwise the inert gas may overflow rapidly, "on the spot" in tissue and blood, and decompression sickness (DCS).DCS can cause skin pruritus, joint pain, respiratory and circulatory disorders. All kinds of manifestations of nervous system damage can cause divers to die quickly. Prevention of DCS is the core of safety assurance for underwater operation.
Hyperbaric oxygen (HBO) is the main means for the treatment of DCS. In recent years, it is found that HBO preconditioning can effectively prevent a variety of ischemic and anoxic damage.DCS also have the pathophysiological characteristics of ischemic anoxia. HBO preconditioning DCS also has a protective effect.
The aim of this study was to observe the preventive effect of HBO preconditioning on DCS in rats and to explore its mechanism preliminarily. The study is divided into two parts.
In the first part, a rat model of air diving decompression sickness was established. The adult Sprague-Dawley (SD) rats were treated with the appropriate "pressure time - decompression rate" hyperbaric exposure program. After the exposure, the rats were immediately placed in a self-developed electronic control cage. The 3 m/min speed movement was 30 min. from the holistic behavior, general and micropathology, and inflammatory reaction. The evaluation index system was established. By controlling the pressure - time - pressure reduction rate and the cage movement method, the model of rat decompression disease with stable incidence could be prepared and the behavior changes of rats could be observed well. Model evaluation system including micro pathology and inflammatory markers.
The second part is to explore the preventive effect and mechanism of HBO preconditioning on DCS in rats. The study is divided into two parts.
(1) HBO preconditioning effect observation. Adult SD rats treated (n=33) with HBO (250 kPa-60min) and simulated air diving (700kPa-100min) after 18 h, and after rapid decompression (200 kPa/min), the animals were moving 30 min at the rate of 3 M / min in the cages. The control animals were pretreated with normal pressure air or hyperoxic high nitrogen mixture. The results showed that the incidence of HBO preconditioning group (30.3%) was significantly lower than that in the air control group (63.3%) (P0.05), and the hyperoxic nitrogen preconditioning had no significant effect on the incidence of DCS (61.5%).
(2) the study of HBO preconditioning mechanism, this part is divided into two steps. First, the role of nitric oxide (nitric oxide, NO) in the preconditioning effect of HBO. The content of NO in the brain, spinal cord and lung of 18h rats after HBO exposure was detected, and the application of nitric oxide synthase (nitric oxide synthetase, NOS) inhibitor, nitroso ammoniacal arginine, was observed. The effect of acid methyl ester (NG-Nitro-L-arginine Methyl Ester, L-NAME) on the prevention of HBO, NO content in the brain, spinal cord and lung increased significantly (P0.05) after.HBO exposure, and L-NAME could inhibit this effect. The NO content of 18h tissues was not significantly changed after exposure, and.L-NAME could significantly prevent the preventive effect of HBO, and the incidence rate rose to 71.4. % (P0.05).
Second, the effect of heat shock protein (HSP) 70 on the prevention of DCS in HBO through NO. The expression of the brain, spinal cord and lung HSP70 in 18 h rats after HBO exposure was detected, and the effects of L-NAME and HSP inhibitors quercetin on the induced expression were observed and the effects on the preventive effect were observed. The expression of HSP70 in the brain, spinal cord and lung of rats increased significantly. L-NAME and Q could inhibit the increase of HSP70,.Q could effectively antagonize the preventive effect of HBO on DCS, and the incidence of DCS in animals increased significantly to 69.2% (P0.05).
The above results can be concluded as follows:
1.18 HBO preconditioning before h can effectively prevent the occurrence of DCS in rats.
2.HBO induced HSP70 expression through NO, thereby playing a protective role in DCS damage.
【学位授予单位】：第二军医大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R840.5

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