亚低温对ARDS大鼠肺组织病理形态及炎症反应的影响

目的：探讨亚低温对大鼠内毒素性急性呼吸窘迫综合征（ARDS）肺组织病理形态及炎症反应的影响。方法：采用大鼠腹腔注射内毒素（LPS，1mg／kg），16h后在气管内滴注LPS（3mg／kg）建立ARDS模型。24只雄性SD大鼠被随机分为3组：对照组（C组）、ARDS组（A组）、亚低温组（M组）。ARDS后3h处死动物，观察肺组织病理形态，计算肺湿重／干重（W／D）比值，检测肺组织中NF-κB活性及TNF-α含量。结果：A组氧合指数（PaO2／Fi02）在ARDS时及ARDS后1、2、3h与C组相比显著下降（P〈O．01）。3组动物病理形态有明显的不同。A组、M组肺W／D均明显高于C组（P〈0．01），M组较A组明显降低（P〈0．01）。A组肺组织NF—κB活性及TNF-α含量明显高于C组（P〈O．01）。M组肺组织NF_κB活性及TNF-α含量明显低于A组（P〈0．01）。结论：亚低温可改善内毒素性ARDS大鼠肺组织病理形态，减轻内毒素性ARDS大鼠肺组织炎症反应。

The Effect ofMild Hypothermia on the Pathomorphism and Inflammatory reaction in the Lung Tissue of Rats with Acute Respiratory Distress Syndrome

Objective To investigate the effect of mild hypothermia on the pathomorphism and inflammatory reaction in the lung tissue of rats with acute respiratory distress syndrome induced by lipopolysaccharide （LPS）. Methods Twenty-four male SD rats were randomly divide into a normal control group, an ARDS group and a mild hypothermic treatment group. The rat model of ARDS was established by intratracheal instillation of LPS （3 mg/kg） 16 hours after intraperitoneal administraion of LPS （1 mg/kg ）. After 3 hours of ARDS, the rats were killed by tapping the carotid artery. The pathomorphism of the lung were observed and lung water content were calculated. The wet-to- dry lung weight ratio was calculated. The activity of NF-r,B and the content of TNF-α
in lung tissue were measured. Results The ratio of PaO2/FiO2 at the time of ARDS and after 1h, 2h, 3h of ARDS were significant lower than those in the control group （P 〈 0.01）. The pathomorphism of lung tissue among three groups were obviously different. The wet-to-dry lung weight ratio in the ARDS group and the mild hypothermic treatment group were significantly higher than those in the control group （P 〈 0.01）. The wet-to-dry lung weight ratio in the mild hypothermic treatment group were significantly lower than those in the ARDS group （P 〈 0.01）.The activity of NF-κB and the content of TNF-α
in lung tissue increased significantly in the ARDS group, as compared with the control group （P 〈 0.01）. The activity of NF-κB and the content of TNF-α
in lung tissue were significantly lower in the mild hypothermic group than in the ARDS group （P 〈 0.01）. Conclusion Mild hypothermia might meliorate the pathomorphism of lung tissue, attenuate inflammation reaction in lung tissue in rats with ARDS.