免疫增强型肠内营养对呼吸机所致肺损伤大鼠炎症反应及免疫功能的影响

Effect of immune-enhancing enteral nutrition on inflammatory reaction and immune function in the rats of ventilation-induced lung injury

目的探讨免疫增强型肠内营养对呼吸机所致肺损伤(VILI)大鼠炎症反应和免疫功能的影响。方法40只大鼠随机分为普通肠内营养组(EN组)和免疫增强型肠内营养组(SEN组),每组各20只,两组中又分别设立正常条件通气对照组(EN1组和SEN1组)和致伤通气组(EN2组和SEN2组)。肠内营养采用灌喂的方式进行。于机械通气0、4、24及72 h分别采集血液标本,测定外周血CD3+、CD4+和CD8+淋巴细胞亚群,血浆TNF-α和IL-6及红细胞膜花生四烯酸(AA)的含量。所有大鼠于机械通气72h后处死,取肺组织行HE染色观察肺组织病理学变化。结果(1)EN2组大鼠致伤通气24及72 h的CD3+、CD4+、CD4+/CD8+较EN1组和SEN1组明显下降,差异有统计学意义(P<0.05),而SEN2组略高于EN1组和SEN1组,但差异无统计学意义(P>0.05)。(2)机械通气4及24 h后,EN2组大鼠TNF-α和IL-6明显升高,较其余3组有显著差异(P<0.05),72 h时EN2组有所下降,但仍较其他组高(P<0.05)。而EN1组、SEN1组及SEN2组间比较无显著差异(P>0.05)。(3)机械通气后4、24、72 h时点EN2组大鼠红细胞膜AA含量下降(P<0.05),SEN2组接近正常水平与EN1组、EN2组比较差异无统计学意义(P>0.05)。结论大鼠在致伤性机械通气前给予免疫增强型肠内营养能减轻炎症反应,增强免疫功能,保护肺组织减轻损伤。

Objective To investigate the effects of immune-enhancing enteral nutritioin therapy on the inflammatory reaction and immune function in the rats of ventilation - induced lung injury. Methods Fourty rats were divided into four groups （ EN1 , EN2 , SEN1 , SEN2, n = 10 ）. All groups were performed mechanic ventilation and fed isocaloric enteral nutrition. EN1 group： tidal volume （VT ） = 8 mL/kg, traditional enteral nutrition ; EN2 group ： VT = 40 mL/kg, traditional enteral nutrition ; SEN1 group ： Vy = 8 mL/kg, immune-enhancing enteral immunonutrition ; SEN2 group ： VT = 40 mL/kg, immune-enhancing enteral immunonutrition. Lymphocyte subsets, TNF-α, IL-6 and contents of arachidonic acid （AA） were determined at different time point（0,4,24,72 h after ventilation）. Results The levels of CD3^＋ , CD4 ^＋ , CD4 ^＋/CD8^＋ in SEN2 group were lower（P 〈 0. 05） than in EN1, EN2 and SEN1 group after 24,72 h of ventilation. The serum concentrations of TNF-α, IL-6 and AA were significantly lower in EN2 than in other three groups （ P 〈 0. 05 ）. Conclusion Immune-enhancing enteral nutrition feeding prior to maehanic ventilatioin can alleriate the damage of immunological function and reduce inflammotory responses.