不同温度海水浸泡对创伤性脑损伤大鼠核心体温、生存状态及脑组织病理变化的影响

Effects of immersion in seawater at different temperatures on core body temperature,survival status,and pathological changes in brain tissues of rats with traumatic brain injury

目的观察不同温度海水浸泡对创伤性脑损伤(TBI)大鼠核心体温、生存状态及脑组织病理变化的影响。方法64只SD大鼠,按照随机数字表法分为8组:sham组、10℃海水浸泡组、15℃海水浸泡组、20℃海水浸泡组、TBI组、TBI合并10℃海水浸泡组、TBI合并15℃海水浸泡组及TBI合并20℃海水浸泡组,每组8只。每只大鼠均浸泡6 h,观察和记录8组大鼠120 min内呼吸频率及直肠温度的变化。伤后24 h统计各组大鼠模型的生存率,并进行Garcia评分。此外,观察或检测sham组、15℃海水浸泡组、TBI组以及TBI合并15℃海水浸泡组的动脉血气指标、脑组织HE染色、脑组织含水量及伊文思蓝(EB)含量。结果与浸泡组或TBI组相比,TBI合并海水浸泡大鼠的生存率明显降低(P<0.05)。与相同浸泡温度的浸泡组相比,TBI合并浸泡大鼠的呼吸频率变化出现更早(P<0.05)。与浸泡组相比,TBI合并海水浸泡大鼠的直肠温度降至环境温度所需时间更短(P<0.05)。与TBI组或15℃海水浸泡组比较,TBI合并15℃海水浸泡组大鼠血pH值、PaCO_(2)、PaO_(2)明显降低,SaO_(2)明显升高(P<0.05)。与相同浸泡温度的海水浸泡组相比,TBI合并海水浸泡大鼠Garcia评分明显降低(P<0.05)。与海水浸泡组相比,TBI合并15℃海水浸泡组大鼠脑组织含水量及EB含量明显增高(P<0.05)。结论在相同浸泡温度下,TBI大鼠更早发生严重的SIH,SIH可加重TBI大鼠脑组织损伤程度。

Objectives To observe the effects of immersion in seawater at different temperatures on core body temperature,survival status,and pathological changes in brain tissues of rats with traumatic brain injury(TBI).Methods A total of 64 Sprague-Dawley(SD)rats were randomly divided into 8 groups:sham group,10℃seawater immersion group,15℃seawater immersion group,20℃seawater immersion group,TBI group,TBI combined with 10℃seawater immersion group,TBI combined with 15℃seawater immersion group,and TBI combined with 20℃seawater immersion group,with 8 rats in each group.The rats in the seawater immersion groups were immersed in seawater for 6 hours.The respiratory rate changes in 120 mins of the rats were observed and recorded,and the rectal temperature changes in 120 mins during immersion were monitored.Twenty-four hours after TBI modeling,the survival rate of rats in each group was assessed,and Garcia scores were determined.In addition,in the sham group,the 15℃seawater immersion group,the TBI group,and the TBI combined with 15℃seawater immersion group,the arterial blood gas indicators,brain tissue HE staining,brain tissue water content,and extravasation of Evan’s blue(EB)staining were measured and observed.Results Compared with the seawater immersion groups and the TBI group,the survival rates of the TBI combined with seawater immersion groups were significantly lower(P<0.05).Compared with the seawater immersion groups at the same immersion temperature,the respiratory rate changes of the TBI combined with seawater immersion groups occurred earlier(P<0.05).Compared with the seawater immersion groups,the duration of rectal temperature dropping to the ambient temperature of the TBI combined with seawater immersion groups were shorter(P<0.05).Compared with the TBI group and the 15℃seawater immersion group,in the TBI combined with 15℃seawater immersion group,the pH value,PaCO_(2),and PaO_(2) significantly decreased,while SaO_(2) significantly increased(P<0.05).Compared with the seawater immersion groups at the same immersion temperature,Garcia scores in the TBI combined with the seawater immersion groups were significantly lower(P<0.05).Compared with the seawater immersion groups,the brain tissue water content and the EB content were significantly increased in the TBI combined with 15℃seawater immersion group(P<0.05).Conclusion At the same immersion temperature,the rats with TBI exhibited a more rapid onset of seawater immersion hypothermia,and seawater immersion hypothermia can increase the degree of the brain injury of the rats with TBI.