目的探讨谷酰胺对新生大鼠高体积分数氧(高氧)肺损伤的保护作用。方法将足月2日龄新生SD大鼠24只随机均分为空气组、谷酰胺组和高氧组,每组8只。空气组新生大鼠不做处理,谷酰胺组新生大鼠实验前腹腔注射0.75 g·kg-1·d-1谷酰胺溶液,高氧组新生大鼠腹腔注射等容量9 g·L-1盐水,连续3 d;高氧组与谷酰胺组新生大鼠置于氧体积分数大于900 mL·L-1模型箱内,空气组新生大鼠置于同一室内常压空气中。分别于实验开始3 d、6 d比较各组新生大鼠体质量,于实验开始6 d无菌条件下处死新生大鼠,取肺组织,24 h后制成石蜡标本,观察病理改变及热休克蛋白70(HSP70)的表达。结果 1.高氧组6 d存活率明显低于空气组(P<0.05);谷酰胺组6 d存活率与空气组比较差异无统计学意义(P>0.05)。高氧下暴露3 d,3组体质量比较差异无统计学意义(P>0.05);高氧暴露6 d,高氧组体质量明显低于空气组(P<0.01),谷酰胺组体质量与空气组比较差异无统计学意义(P>0.05)。2.高氧组肺水肿程度最严重,其肺湿质量/干质量值明显高于空气组(P<0.05);谷酰胺组肺湿质量/干质量值与空气组比较差异无统计学意义(P>0.05)。3.高氧暴露6 d,高氧组肺泡内有出血和大量渗出的炎性细胞、大量粉染的蛋白性液体,肺泡壁严重充血水肿;谷酰胺组肺泡内极少量红细胞渗出,肺泡腔内见粉染的水肿液,肺泡壁增厚。4.高氧暴露6 d,高氧组、谷酰胺组肺组织HSP70蛋白表达量均较空气组显著增加(Pa<0.01),谷酰胺组肺组织HSP70蛋白表达量较高氧组显著增加(P<0.01)。结论预防性使用谷酰胺可明显改善高氧肺损伤新生大鼠的生存率,有利于新生大鼠的生长发育;预防性使用谷酰胺能增加高氧肺损伤新生大鼠肺组织HSP70的表达,表明谷酰胺对高氧肺损伤的保护作用与HSP70表达相关。 Objective To investigate the protective effect of glutamine on high volume fraction oxygen (hyperoxia) lung injury in neonatal rats. Methods Twenty-four newborn Sprague-Dawley rats of 2-day-old full-term were randomly divided into air group, glutamine group and hyperoxia group, with 8 rats in each group. In the air group, the newborn rats were not treated. The glutamate group was injected intraperitoneally with 0.75 g · kg -1 · d -1 glutamine solution before the experiment. The neonatal rats in the hyperoxia group were injected intraperitoneally with the same volume of 9 g · L -1 saline For 3 consecutive days. Neonatal rats in hyperoxia group and glutamine group were placed in the model tank with the volume of oxygen greater than 900 mL · L-1, and the neonatal rats in the air group were placed in the same indoor air. Neonatal rats were sacrificed on the 6th day after the start of the experiment, and the lungs were removed. After 24 hours, paraffin wax specimens were obtained and pathological changes and heat shock were observed Protein 70 (HSP70) expression. The survival rate in 6-day hyperoxia group was significantly lower than that in air group (P <0.05). There was no significant difference in 6-day survival rate between glutamine group and air group (P> 0.05). Compared with the air group (P <0.01), the body mass of the hyperoxia group was significantly lower than that of the air group (P <0.01) Compared with the air group, the difference was not statistically significant (P> 0.05). 2. The degree of pulmonary edema in hyperoxia group was the most serious, and the lung wet mass / dry mass value was significantly higher than that in air group (P <0.05). There was no significant difference in lung wet mass / dry mass value between glutamine group and air group P> 0.05). In hyperoxia group, there were bleeding inflammatory cells in the alveoli and massive exudation of inflammatory cells in the hyperoxia group. A large amount of protein-contaminated liquid was found in the alveoli, and the alveolar wall was severely hyperemic and edematous. In the glutamine group, a very small amount of erythrocyte exuded in the alveoli, See intraluminal dyed edema, alveolar wall thickening. The expression of HSP70 protein in lung tissue of hyperoxia group and glutamine group increased significantly (P <0.01) 6 days after hyperoxia exposure, while the expression of HSP70 protein in lung tissue of glutamine group increased significantly (P <0.01). Conclusion Preventive use of glutamine can significantly improve the survival rate of neonatal rats with hyperoxia-induced lung injury, is conducive to the growth and development of newborn rats; preventive use of glutamine can increase lung tissue HSP70 expression in neonatal rats with hyperoxia-induced lung injury, indicating The protective effect of glutamine on hyperoxia-induced lung injury is related to the expression of HSP70.