高压氧对重度海水浸泡性体温过低大鼠复温效能的影响

Effect of hyperbaric oxygen on rewarming efficiency in rats with severe seawater immersion hypothermia

目的观察高压氧治疗对重度海水浸泡性体温过低大鼠复温效能的影响。方法68只SD雄性大鼠(腹腔预置温度记录器),按照实验设计分为正常对照组(不做任何处理,n=8)、低温对照组(15℃海水浸泡5 h,n=20)、被动复温组(15℃海水浸泡5 h+被动复温,n=20)、高压氧辅助治疗组(15℃海水浸泡5 h+被动复温+高压氧辅助治疗,n=20)。连续记录4组大鼠体温变化;处理完毕即时采集存活大鼠外周血并取材,检测重要氧化应激指标、炎症因子及炎症相关生化指标血清水平,用以评价全身氧化应激状态和炎症反应程度;检测凝血相关指标,用以评价凝血功能;HE染色观察重要脏器病理改变,用以评价组织损伤程度。结果(1)15℃海水浸泡,大鼠体温随浸泡时间的延长呈进行性降低,至浸泡5 h时为15℃,达到大鼠重度体温过低标准。被动复温后,高压氧辅助治疗组大鼠体温回升更快,存活大鼠至复温15 h时基本达到正常水平,复温速率与被动复温组比较差异有统计学意义(均P<0.05)。(2)浸泡5 h时,存活大鼠血清氧化应激指标丙二醛(MDA)明显升高、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)明显降低,炎症因子肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-6、IL-1β明显升高,相关酶类LDH、ALT、AST亦明显升高(均P<0.05);复温48 h时,上述指标均有恢复,但高压氧辅助治疗组更明显,各项指标基本达到正常水平,与被动复温组比较差异有统计学意义(均P<0.05)。(3)浸泡5 h时,存活大鼠凝血指标PT、APTT明显延长,纤维蛋白原(FIB)含量明显升高(均P<0.05);复温48 h时,高压氧辅助治疗组活化部分凝血活酶时间(APTT)和凝血酶原时间(PT)基本恢复正常水平,与被动复温组比较差异有统计学意义(P<0.05)。(4)组织病理显示,浸泡5 h时,肝、肾细胞出现不同程度肿胀,肝窦扩张,间隙变窄,并可见散在出血;复温48 h时,肝、肾组织血管扩张,血供增加,周围组织细胞恢复正常形态;与被动复温组比较,高压氧辅助治疗组上述改善更明显。结论高压氧辅助治疗能够有效提高重度海水浸泡性体温过低大鼠的被动复温效能,减轻氧化应激和炎症反应,纠正凝血功能障碍,促进肝肾结构和功能恢复,具有一定的保护作用。

Objective To observe the effect of hyperbaric oxygen therapy on the efficiency of rewarming severe seawater immersion hypothermia in rats.Methods A total of 68 male SD rats were intraperitoneally implanted with temperature recorder before experiment and then randomly divided into normal control group(no treatment,8 rats,NC),hypothermia control group(immersed in 15℃seawater for 5 h,20 rats,HC),passive rewarming group(immersed in 15℃seawater for 5 h+passive rewarming,20 rats,PR),hyperbaric oxygen therapy group(immersed in 15℃seawater for 5 h+passive rewarming+hyperbaric oxygen therapy,20 rates,PRH).The temperature changes of rats in 4 groups were recorded continuously.After treatment,the peripheral blood and tissue samples of the surviving rats were collected immediately.The serum levels of important oxidative stress indexes,inflammatory factors,and serum inflammation related biochemical indexes were detected to evaluate the systemic oxidative stress state and the degree of inflammatory response;coagulation related indexes were measured to evaluate coagulation function;HE staining was used to observe the pathological changes of important organs and evaluate the degree of tissue damage.Results(1)The temperature of rats gradually decreased with the prolongation of immersion time,and reached 15℃at the time of immersion for 5 hours,meeting the criterion of severe hypothermia in rats.After passive rewarming,the temperature of rats in PRH group rose faster,and the survival rats basically reached the normal level by the time of rewarming for 15 h.The rewarming rate was different from that in the PR group.(2)At the time of immersion for 5 h,the serum oxidative stress index MDA significantly increased,SOD and GSH-PX significantly decreased,the inflammatory factors TNF-α,IL-6,and IL-1βsignificantly increased,and the related enzymes LDH,ALT,and AST were also significantly increased(all P<0.05).After 48h rewarming,all the above indexes recovered;especially,the recovery of those indexes in the PRH group was more significant,and all the indexes basically reached the normal levels,which were different from those in the PR group(P<0.05).(3)The coagulation index PT and APTT were significantly prolonged and the FIB content was significantly increased in the surviving rats(P<0.05).After 48 h rewarming,PT and APTT in the PRH group basically recovered to normal levels,which were different from those in the PR group(P<0.05).(4)According to histopathology test,liver and kidney cells showed varying degrees of swelling,hepatic sinus dilation,gap narrowing,and scattered bleeding.After 48 h rewarming,blood vessels of liver and kidney tissue dilated,blood supply increased,and surrounding tissue cells recovered to normal shape.Compared with the PR group,the above improvements were more obvious in the PRH group.Conclusion Hyperbaric oxygen therapy can effectively improve the efficiency of passive rewarming of severe seawater immersion hypothermia in rats,alleviate oxidative stress and inflammatory reactions,correct coagulation dysfunction,and promote the recovery of liver and kidney structure and function,with a certain protective effect.