肌苷对快速上浮脱险致减压病预防作用的实验研究

发布时间：2018-04-15 23:10

本文选题：减压病 + 快速上浮脱险　；参考：《第二军医大学》2017年硕士论文

【摘要】：目的:在以快速上浮脱险方法进行逃生的过程中,失事潜艇艇员可因高压暴露时间超过允许的安全时间而使体内溶解的惰性气体原地生成气泡,进而导致减压病(decompression sickness,DCS)的发生。本研究目的是观察肌苷预处理对模拟不安全快速上浮脱险大鼠DCS发病的预防作用并探索相关机制。方法:1.以成年雄性Wistar大鼠为研究对象,随机分为正常对照组、DCS对照组、低剂量肌苷组、中剂量肌苷组、高剂量肌苷组、氯吡格雷组。除正常对照组外,大鼠经“以PT=P0′2T/7指数曲线加压至1.6 MPa并稳压242 s后,以3 m/s速率匀速减至0.1 MPa”的加压-减压方案处理。低/中/高剂量肌苷组分别在加压前30 min腹腔给肌苷50/100/200 mg/kg,氯吡格雷组在加压前连续3 d管饲氯吡格雷50mg/kg/日。正常对照组、DCS对照组加压前30 min给同体积的生理盐水。出舱后观察各组发病和死亡情况,并在0.5 h、12 h、24 h检测肺组织的病理、湿干重比、炎症因子(TNF-a、IL-6)、凋亡因子(Bcl-2、Bax、caspase-3)、MAPK通路蛋白(ERK、p38、JNK)的变化情况。2.根据前期实验结果选择100 mg/kg肌苷、0.5 h取材检测的方案,在使用肌苷预处理的基础上分别利用A_(2A)受体拮抗剂SCH52861、A_3受体拮抗剂MRS1523、ERK通路阻断剂AZD6244处理大鼠,观察特异性拮抗剂对肌苷改善DCS发病、肺病理损伤、炎症反应、凋亡反应等的影响,探究A_(2A)受体、A_3受体、ERK通路在肌苷预防DCS机制中的作用。结果:1.模拟不安全快速上浮脱险可造成大鼠DCS的发生(发病率95%,死亡率50%)。与正常对照组比,DCS对照组可见肺组织的病理评分、湿干重比、TNF-a、IL-6增加,凋亡因子caspase-3激活上调,抗凋亡指标Bcl-2/Bax下降。2.和DCS对照组比,100~200 mg/kg肌苷可有效改善大鼠DCS的发病和死亡情况,且效果与氯吡格雷基本相当。肌苷还可降低肺病理评分、湿干重比、TNF-a、IL-6和裂解型caspase-3水平,上调Bcl-2/Bax和ERK激活水平。与12 h、24 h相比,此现象在出舱后0.5 h最明显。3.在肌苷预处理之前使用A_(2A)受体拮抗剂SCH52861、A_3受体拮抗剂MRS1523、ERK通路阻断剂AZD6244,可使大鼠DCS相关损伤指标加重,减弱了肌苷的这种预防作用。结论:1.不安全的快速上浮脱险可导致DCS的发生,在12 h内,大鼠可表现出明显的肺组织病理损伤和水肿、炎症反应和凋亡水平升高。2.100 mg/kg肌苷预处理可有效改善DCS发病、死亡情况和肺组织损伤、炎症反应、凋亡情况,且在DCS早期即可发挥明显的保护作用。3.肌苷可通过结合A_(2A)受体、A_3受体使ERK信号通路激活,进而上调抗凋亡因子,降低凋亡水平,产生保护肺组织、改善DCS发病死亡情况的作用。
[Abstract]:Objective: in the process of escape by fast floating escape, shipwrecked submarine crew can cause the dissolved inert gas to form bubbles in situ because the time of high pressure exposure exceeds the permitted safe time, and then lead to decompression decompression syndrome (DCSs).The aim of this study was to investigate the preventive effect of inosine pretreatment on the pathogenesis of DCS in simulated unsafe and fast floating rats.Method 1: 1.Adult male Wistar rats were randomly divided into normal control group, low dose inosine group, middle dose inosine group, high dose inosine group and clopidogrel group.In addition to the normal control group, the rats were treated with a pressure-decompression regimen of "pressurized with PT=P0'2T/7 exponent curve to 1.6 MPa and steady pressure for 242s, and reduced to 0.1 MPa at a rate of 3 m / s".The low / middle / high dose inosine group was intraperitoneally given inosine 50 / 100 / 200 mg / kg 30 min before compression, while clopidogrel group was given clopidogrel 50mg/kg/ day for 3 days before compression.The normal control group was given the same volume of normal saline 30 min before compression.The incidence and death of each group were observed, and the pathological changes of lung tissue, wet dry weight ratio (WDW), TNF-a IL-6 and apoptosis factor Bcl-2BaxCaspase-3 MAPK pathway protein ERK p38 JNK2 were detected at 0.5 h and 12 h and 24 h respectively.According to the results of the previous experiment, we selected the method of #number0# mg/kg inosine for 0. 5 h. On the basis of pretreatment with inosine, we treated the rats with AZD6244, a receptor antagonist, SCH 52861A 3 receptor antagonist, MRS1523 ERK pathway blocker, respectively, on the basis of pretreatment with inosine.To observe the effects of specific antagonists on the effects of inosine on the pathogenesis of DCS, lung pathological injury, inflammatory reaction and apoptosis reaction, and to explore the role of the A3 receptor ERK pathway in the prevention of DCS by inosine.The result is 1: 1.Simulated unsafe fast buoyancy can lead to the occurrence of DCS in rats (incidence 95%, mortality 50%).Compared with normal control group, lung tissue pathological score, wet and dry weight increased, apoptosis factor caspase-3 activation increased, and Bcl-2/Bax decreased by 0.2, compared with normal control group.Compared with the control group of DCS, the inosine of 200 mg/kg could effectively improve the incidence and death of DCS in rats, and the effect was almost the same as that of clopidogrel.Inosine also decreased lung pathological score, wet / dry weight ratio (WDW), TNF-a IL-6 and lytic caspase-3, and upregulated the activation of Bcl-2/Bax and ERK.Compared with 12 h / 24 h, this phenomenon was the most obvious at 0.5 h after departure.Before the pretreatment of inosine, the antagonist SCH 52861A / S 3 receptor antagonist MRS 1523 ERK pathway blocker AZD6244 could aggravate the damage index of DCS in rats and weaken the preventive effect of inosine.Conclusion 1.Unsafe rapid floating escape can lead to the occurrence of DCS. Within 12 h, the rats showed obvious lung tissue pathological injury and edema. Pretreatment with increased level of inflammatory reaction and apoptosis. 2.100 mg/kg inosine pretreatment could effectively improve the pathogenesis of DCS.Death and lung tissue injury, inflammation, apoptosis, and early DCS can play a significant protective role. 3.Inosine can activate the ERK signaling pathway by binding with Astack 2A) receptor, and then up-regulate the anti-apoptotic factor, decrease the level of apoptosis, protect lung tissue and improve the incidence and death of DCS.
【学位授予单位】：第二军医大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R845.21

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