亚低温对ARDS大鼠肺组织过氧化及肺通透性的影响

The Effect of Mild Hypothermia on the Overoxidation and Pulmonary Microvascular Permeability in the Acute Respiratory Distress Syndrome Rats' Lungs

目的探讨亚低温对大鼠内毒素性急性呼吸窘迫综合征(ARDS)肺组织过氧化反应及肺通透性的影响。方法采用大鼠腹腔注射脂多糖(LPS,1 mg/kg),16 h后再气管内滴注LPS(3 mg/kg)建立ARDS模型。72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)。分别于ARDS时及ARDS后2、4、6 h处死动物,检测肺组织超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、髓过氧化物酶(MPO)活性以及肺通透指数。结果与C组大鼠比较,A组大鼠在上述时间点SOD活性明显降低,MDA含量、MPO活性及肺通透指数明显升高(P<0.01)。与A组比较,M组大鼠SOD活性明显升高,MDA含量、MPO活性及肺通透指数明显降低(P<0.01)。结论亚低温可减轻内毒素性ARDS大鼠肺组织过氧化反应,降低肺通透性,有利于ARDS治疗。

Objective To investigate the effect of mild hypothermia on the overoxidation and pulmonary mirovascular permeability in the lung tissue of rats with acute respiratory distress syndrome （ARDS） induced by lipopolysaccharide （LPS）. Methods Seventy-two male Sprague-Dawley rats were randomly divide into normal control group（group C）,ARDS group（group A） and mild hypothermic treatment group（group M）. ARDS was induced by intratracheal instillation of LPS （3 mg/kg） 16 hours after intraperitoneal administraion of LPS（1 mg/kg）. Rats were killed by tapping the carotid artery Immediately after the inducement of ARDS, 2 hours,4 hours and 6 hours post the inducement of ARDS respectively. The pathomorphism of the lung were observed and pulmonary microvascular permeability were calculated. The content of MDA in lung tissue was measured. The activation of myeloperoxidase （MPO） and superoxide dismutase （SOD） were examined. Results Compared with group C,goup M,the activation of MPO and the index of pulmonary permeability in the ARDS group increased significantly（P〈0.01）, whereas the activation of SOD decreased significantly（P〈0. 01）. Compared with group A, group M, the activation of MPO and the index of pulmonary permeability significantly decreased in the mild hypothermic treatment group（P〈0. 01）. whereas the activation of SOD significantly increased （P〈0.01）. Conclusion Mild hypothermia might meliorate the overoxidation response and attenuate pulmonary microvaseular permeability in ARDS rats＇ lungs. It could be in favor of the treatment of ARDS.