血管紧张素-（1-7）及其受体激动剂AVE0991治疗大鼠急性肺损伤的效果

Effect of angiotensin-（1-7） and receptor agonist of angiotensin-（1-7） AVE0991 on acute lung injury in rats

中文关键词: 血管紧张素-（1-7）  血管紧张素-（1-7）特异性受体激动剂  急性肺损伤  肺动脉压

英文关键词: Angiotensin-（1-7）  Specific receptor agonist of angiotensin-（1-7）  Acute lung injury  Pulmonary artery pressure

中文摘要:

      
目的 探讨血管紧张素-（1-7）［Ang-（1-7）］及其特异性受体激动剂AVE0991用于治疗大鼠急性肺损伤（ALI）的效果。
方法 选择清洁级雄性SD成年大鼠45只，6～8周龄，体重250～300 g。采用随机数字表法将大鼠分为五组：对照组（C组）、ALI组（L组）和Ang-（1-7）组（LA组）、AVE0991组（LAV组）和Ang-（1-7）抑制剂（A-779）（LAN组），每组9只。L组静脉注射脂多糖（LPS） 5 mg/kg，机械通气V_T 15 ml/kg，持续4 h；C组静脉注射与 L组等容量的生理盐水，机械通气V_T 8 ml/kg，持续4 h；LA组、LAV组和LAN组静注LPS 5 mg/kg，机械通气V_T 15 ml/kg，持续2 h后分别静注Ang-（1-7） 50 pmol·kg^-1·min^-1、AVE0991 500 pmol·kg^-1·min^-1和A-779 100 pmol·kg^-1·min^-1，继续机械通气2 h 。记录机械通气前（T₀）、机械通气 2 h（T₁）、药物处理 30 min（T₂）、60 min（T₃）、90 min（T₄）、120 min（T₅）时的肺动脉压（PAP）；T₁和T₅时取肺动脉血行血气分析，记录LA组、LAV组和LAN组的PaCO₂、PaO₂。处死大鼠，对支气管肺泡灌洗液（BALF）采用瑞氏-姬姆萨染色行白细胞分类计数，采用ELISA法检测股静脉血TNF-α浓度，采用肺组织称重法计算肺湿/干重比（W/D），采用HE染色观察肺组织病理改变并评估肺损伤程度。
结果 与T₁时比较，T₂时LA组PAP明显降低（P<0.05），T₂—T₄时LAV组PAP明显降低（P<0.05），T₅时LA组PaO₂明显升高（P<0.05）。与C组比较，L组和LAN组BALF中白细胞计数明显增多（P<0.05），L组、LA组、LAV组和LAN组血清TNF-α浓度和W/D值明显升高（P<0.05）。与L组比较，LA组和LAV组BALF中白细胞计数、血清TNF-α浓度和W/D值明显降低（P<0.05）。与LA组比较，LAN组BALF中白细胞计数、血清TNF-α浓度和W/D值明显升高（P<0.05）。C组肺组织损伤轻微，L组肺组织损伤中度，LA组和LAV组肺组织损伤轻度，LAN组肺组织损伤严重。
结论 Ang-(1-7)及AVE0991可以减轻大鼠大潮气量通气合并LPS所致ALI的炎症反应，改善肺损伤，具有肺保护作用。

英文摘要:

      
Objective To investigate the effectiveness of angiotensin-(1-7) and specific receptor agonist of angiotensin-(1-7) AVE0991 in the treatment of the acute lung injupy (ALI) in rats.
Methods Forty-five clean adult male SD rats, aged 6-8 weeks, weighing 250-300 g, were divided into five groups by random number table method: control group (group C), ALI group (group L), Ang-(1-7) group (group LA), AVE0991 group (group LAV), and Ang-(1-7) inhibitor (A-779) group (group LAN), 9 rats in each group. Group L was intravenously injected with lipopolysaccharide (LPS) 5 mg/kg and mechanical ventilation tidal volume 15 ml/kg for 4 hours. Group C were injected intravenously with the same volume of normal saline with group L, with mechanical ventilation tidal volume of 8 ml/kg for 4 hours. Groups LA, LAV, and LAN were intravenously injected LPS 5 mg/kg. After mechanical ventilation with a tide volume of 15 ml/kg for 2 hours, Ang-(1-7) 50 pmol·kg^-1·min^-1, AVE0991 500 pmol·kg^-1·min^-1, and A-779 100 pmol·kg^-1·min^-1 were injected intravenously with continuing mechanical ventilation for 2 hours. Pulmonary artery catheterization was used to record the pulmonary artery pressure (PAP) before mechanical ventilation (T₀), 2 hours after mechanical ventilation (T₁), 30 minutes (T₂), 60 minutes (T₃), 90 minutes (T₄), and 120 minutes (T₅) after drug treatment. Pulmonary artery blood was collected at T₁ and T₅ for blood gas analysis, and PaCO₂ and PaO₂ of groups LA, LAV, and LAN were recorded. The rats were sacrificed, and the bronchoalveolar perfusion fluid (BALF) was stained with Wright-Giemsa staining for cell classification and counting. The plasma samples were collected from femoral vein blood to detect the concentration of TNF-α by ELISA. The lung wet/dry weight ratio (W/D) was calculated by lung tissue weighing method. The pathological changes of lung tissue were observed and the degree of lung injury was evaluated by HE staining.
Results Compared with T₁, PAP was decreased significantly at T₂ in group LA (P < 0.05), PAP was significantly decreased in group LAV at T₂-T₄(P < 0.05), PaO₂ was significantly increased in group LA at T₅(P < 0.05). Compared with group C, leukocyte count of BALF in groups L and LAN was significantly increased (P < 0.05), the concentration of TNF-α, W/D in groups L, LA, LAV, and LAN were significantly increased (P < 0.05). Compared with group L, leukocyte count of BALF, the concentration of TNF-α, W/D in groups LA and LAV were significantly decreased (P < 0.05). Compared with group LA, leukocyte count of BALF, the concentration of TNF-α, W/D in group LAN were significantly increased (P < 0.05). The lung tissue damage was mild in group C, moderate in group L, mild in group LA and LAV, and severe in group LAN.
Conclusion Ang-(1-7) and AVE0991 can alleviate the inflammatory response during high tidal volume ventilation combined with LPS induced ALI in rats, improve lung injury, and have lung protective effects.