高原寒冷环境大鼠急性肺水肿模型的建立

Establishment of a rat model of acute pulmonary edema in cold environment at high altitude

目的建立高原低压缺氧、寒冷环境大鼠急性肺水肿模型,同时探讨寒冷因素对高原急性肺水肿形成的影响。方法雄性健康SD大鼠100只,随机分为2组(n=50):高原常温组(HN组)和高原寒冷组(HC组)。每组再按5个时间点分成5个亚组(n=10):0、24、48、72、120 h。将这两组大鼠放置人工实验舱内模拟海拔7000 m的低压缺氧环境,并设置常温和寒冷两种环境温度,在相应时间点麻醉大鼠,取肺泡灌洗液(BALF)以及肺组织。检测BALF蛋白质浓度及肺组织W/D值;将肺组织制片,HE染色,观察病理变化。结果HN组及HC组大鼠肺组织W/D值随暴露时间呈升高趋势,HN组的大鼠肺组织W/D值在72 h时达到最高,HC组的大鼠肺组织W/D值在48 h时达到最高,在48、72和120 h,HC组的肺组织W/D值均高于HN组,差异均具有统计学意义(P<0.05)。BALF蛋白质浓度和肺组织病理的变化趋势与肺组织W/D值的变化相同,HN组的BALF蛋白质浓度和肺损伤评分均在72 h时达到最高,其值依次为(0.2802±0.0243)、(1.7778±0.4410)mg/mL,HC组的BALF蛋白质浓度和肺损伤评分在48 h时达到最高,其值分别为(0.3352±0.0204)、(2.8889±1.0541)mg/mL,在48、72和120 h,HC组的BALF蛋白质浓度和肺损伤评分均高于HN组,差异均具有统计学意义(P<0.05)。结论在人工实验舱模拟海拔7000 m高原低压缺氧环境中,在寒冷条件(白天温度15℃,夜间温度5℃)下暴露48 h可成功构建SD大鼠急性高原肺水肿模型,而常温环境需要72 h才可成模,研究提示寒冷因素能促进急性高原肺水肿的发生发展。

Objective To establish a rat model of acute pulmonary edema under high-altitude hypobaric hypoxia and a cold environment, and to explore the effect of cold factors on the formation of acute high-altitude pulmonary edema. Methods One-hundred healthy male SD rats were randomly divided into two groups(n=50): HN and HC groups. Each group was divided into five subgroups(n=10) with five time points: 0, 24, 48, 72 and 120 h. The two groups of rats were placed in an artificial experimental cabin to simulate hypobaric hypoxia at an altitude of 7000 m, different ambient temperatures were set, the rats were anesthetized at the corresponding time points, and alveolar lavage fluid and lung tissue were collected. The BALF protein concentration and W/D ratio of lung tissue were measured. The lung tissue was sectioned and stained with HE to observe pathological changes. Results The W/D ratio of lung tissue was increased in HN and HC groups. The W/D ratio of lung tissue in the HN group reached the highest at 72 h, and that in the HC group reached the highest at 48 h. At 48, 72 and 120 h, the W/D ratio of lung tissue in the high-altitude cold group was significantly higher than that in the HN group(P<0.05). The trend in the changes of the BALF protein concentration and lung pathology was the same as that of the lung W/D ratio. The BALF protein concentration and lung injury score in the HN group reached the highest at 72 h, which were(0.2802 ± 0.0243)and(1.7778 ± 0.4410)mg/mL respectively, and the BALF protein concentration and lung injury score in HC group reached the highest at 48 h, and their values were(0.3352 ± 0.0204) and(2.8889 ± 1.0541) mg/mL respectively. At 48, 72 and 120 h, the BALF protein concentration and lung injury score in the HC were higher than those in the HN group(P<0.05). Conclusions In the simulated hypobaric hypoxia environment at high altitude of 7000 m, the SD rat model of acute high-altitude pulmonary edema was successfully established after exposure to cold conditions(daytime temperature: 15℃;nighttime temperature: 5℃) for 48 h, but it required 72 h at normal temperature. This study suggests that cold factors promote the occurrence and development of acute high-altitude pulmonary edema.