谷氨酰胺对肺部感染肺炎克雷伯菌大鼠的保护作用

Effect of glutamine on protection of rats with Klebsiella pneumoniae pulmonary infection

目的研究全胃肠外营养(total parenteral nutrition,TPN)中谷氨酰胺对肺部感染肺炎克雷伯菌大鼠的保护作用。方法将50只SD大鼠随机平均分成A、B、C、D、E 5个组,第1~2天,给予普通饮食,同时静脉泵入生理盐水80 ml/kg·d;第3~7天,A、B组大鼠给予普通饮食同时静脉泵入生理盐水160 ml/kg·d,C、D、E组大鼠禁食,C组静脉泵入不含谷氨酰胺的标准肠外营养液160 ml/kg·d,D、E组静脉泵入内含谷氨酰胺的标准肠外营养液160 ml/kg·d(D组谷氨酰胺按0.5 g/kg·d配制,E组按2.5 g/kg·d配制);第8天,A组大鼠气管内注入生理盐水0.3 ml,B、C、D、E组大鼠气管内注入肺炎克雷伯菌0.3 ml。48 h后,取外周血及肺泡灌洗液进行白细胞计数、总蛋白定量、肿瘤坏死因子α(TNF-α)、白介素1-β(IL1-β)、白介素-8(IL-8)、C-反应蛋白(CRP)、降钙素原(PCT)、血胱抑素C(Cys C)检测;光镜下观察肺组织病理变化。结果实验结束时C组大鼠体质量低于A、B、D组(P<0.05);C组大鼠死亡只数多于D、E组(P<0.05);5组大鼠白细胞计数、IL-1β、IL-8、TNF-α、CRP、PCT、Cys-C水平比较差异有统计学意义(P<0.05);C组白细胞计数及血清IL-1β、IL-8、TNF-α、CRP、PCT、Cys-C水平均高于D、E组,E组血清IL-1β、TNF-α、CRP、PCT、Cys-C高于D组(P<0.05);光镜下C组大鼠肺组织损伤程度重于D、E组。结论谷氨酰胺对接受肠外营养的大鼠有保护作用,可以提高肺的抗感染能力,减轻严重感染造成的损伤。

OBJECTIVE To explore the effect of total parenteral nutrition(TPN)with glutamine on protection of rats with Klebsiella pneumoniae pulmonary infection.METHODS A total of 50 Sprague-Dawley rats were randomly divided into five groups,named the group A,B,C,D and E.In the first two days,they were fed on regular diet and injected 80 ml/kg·d normal saline(NS)intravenously,then the concentration of NS in group A and B were changed to 160 ml/kg·d and regular diet remained on the 3 rd-7 th day,however,the rats of the group C,D and E were treated with fasting,the group C was intravenously pumped with 160 ml/kg·d of standard parenteral nutrition solution free from glutamine,the group D and E were intravenously pumped with 160 ml/kg·d of standard parenteral nutrition solution containing with glutamine(the group D was prepared with 0.5 g/kg·d of glutamine,the group E was prepared with 2.5 g/kg·d);the group A was intratracheally injected with 0.3 ml of normal saline on 8 th day,the group B,C and D were intratracheally injected with 0.3 ml of K.pneumoniae,48 hours later,the peripheral blood and alveolar lavage fluid specimens were collected to detect the white blood cell counts,total protein quantification,tumor necrosis factor-α(TNF-α),interleukin 1-β(IL1-β),interleukin-8(IL-8),C-reactive protein(CRP),procalcitonin(PCT)and cystatin C(Cys C).The pathological characteristics of lung tissues were observed by using light microscope.RESULTS The body mass of rats of the group C was significantly lower than that of the group A,B and D at the end of experiment(P<0.05).The number of dead rats of the group C was significantly larger than that of the group C and E(P<0.05).There were significant differences in the levels of white blood cell,IL-1β,IL-8,TNF-α,CRP,PCT and Cys-C among the 5 groups of rats(P<0.05).The levels of white blood cell,serum IL-1β,IL-8,TNF-α,CRP,PCT and Cys-C of the group C were significantly higher than those of the group D and E,the levels of serum IL-1β,TNF-α,CRP,PCT and Cys-C of the group E were significantly higher than those of the group D(P<0.05).The damage of lung tissue of the rats was severer in the group C than in the group D and E under the light microscope.CONCLUSION Glutamine has protective effect on the rats that receive TPN,prevents the pulmonary infection and alleviate the damage due to severe infection.