控制性肺膨胀对急性呼吸窘迫综合征家兔肺外器官炎症反应的影响

Effect of sustained inflation on inflammatory response of extra pulmonary organs in acute respiratory distress syndrome in rabbit

目的 研究控制性肺膨胀(SI)对急性呼吸窘迫综合征(ARDS)家免肺外器官炎症反应的影响。方法 生理盐水肺泡灌洗法复制ARDS家兔模型。实验动物随机分为对照组、ARDS组、小潮气量(VT)+最佳呼气末正压组(LVBP组)和SI组。机械通气4 h后,逆转录-聚合酶链反应(RT-PCR)检测肝、肠组织肿瘤坏死因子-α(TNF-α)和自细胞介素-10(IL-10)mRNA表达;酶联免疫吸附法检测肝、肠组织TNF-α和IL-10浓度,同时测定髓过氧化物酶(MPO)和丙二醛(MDA)含量。结果 SI组肝、肠组织TNF-α mRNA表达明显低于ARDS组和LVBP组(P均<0.05);肝、肠组织IL-10 mRNA表达均显著低于ARDS组和LVBP组(P均<0.05)。各组间肝、肠组织TNF-α、IL-10、MPO和MDA含量比较无统计学差异。结论 SI可抑制ARDS家免肺外器官细胞因子mRNA的表达,下调肺外器官炎症反应。

Objective To evaluate the influence of sustained inflation (SI) on inflammatory response of extra pulmonary organs in acute respiratory distress syndrome (ARDS) in rabbit. Methods The ARDS rabbit model were replicated by saline alveoli - lavage. The rabbits were randomly divided into four groups : (1)normal group;(2)ARDS group; (3)low - volume (VT) + best end -expiratory pressure group (LVBP): VT 6 ml/kg, PEEP 2 cm H2O(1 cm H2O = 0. 098 kPa) greater than the pressure of lower inflection point in pressure - volume curve (Pinf); (4) SI group: same settings as LVBP group plus SI performed every hour. After 4 hours of ventilation, liver and intestine homogenates were prepared to assay tumor necrosis factor(TNF)-α and interleukin (IL)- 10 levels by enzyme - linked immunoadsorbent assay and their mRNA expression by reverse transcription - polymerase chain reaction. Myeloperoxidase (MPO) and malondialdehyde(MDA) were assessed at the same time. Results In SI group, TNF - α mRNA expression in the liver and intestine tissues (24. 82±7. 88 and 25. 06±10. 57) were decreased significantly compared with ARDS(36. 88±6. 83 and 36. 48±8. 23) and LVBP groups (42. 34 ± 8. 55 and 37. 59 ± 10. 63, all P<0. 05). The expression of IL - 10 mRNA in the liver and intestine of rabbits in SI group(17. 31 ± 5. 72 and 10. 90 ± 3.30) was lower than that of ARDS (24. 64 ± 3. 85 and 24. 31 ±7. 69) and LVBP group (25. 03 ± 9. 38 and 21. 83±7. 34, all P<0. 05) signifantly. In SI group, the levels of TNF - α and IL - 10 in liver and intestine tissue were similar to that of the other groups. The contents of MPO and MDA had no difference compared with the other groups too. Conclusion SI can down - regulate inflammatory mediator expression of extra - pulmonary organs in rabbits with ARDS, and it may inhibit the inflammatory response in extra pulmonary organs.