巨噬细胞移动抑制因子在油酸致急性肺损伤动物模型肺组织中的表达

目的:研究急性肺损伤(ALI)大鼠肺组织中巨噬细胞移动抑制因子(MIF)的表达与血气改变、肺系数及肺脏病理变化、炎症细胞浸润的关系。方法:静脉注射油酸制造急性肺损伤大鼠模型为油酸组,静脉注射生理盐水作对照组。静脉注射油酸或生理盐水6 h后,测定左心PaO₂、PaCO₂及肺系数,同时采用微波免疫组化双重染色的方法,对比研究对照组和急性肺损伤组肺组织中MIF表达及肺间实质中MIF^＋、鼠抗CD68抗体(ED₁)、MIF⁺/ED₁⁺细胞数与血气指标、肺系数改变的关系。结果:油酸组PaO₂明显低于对照组而PaCO₂高于对照组(P＜0.01)。油酸组肺系数(1.02±0.08)高于对照组(0.70±0.05),P＜0.01。急性肺损伤大鼠肺组织中MIF表达明显多于和强于对照组,ALI肺组织中MIF⁺、ED₁⁺、MIF⁺/ED₁^＋细胞数与PaO₂、肺系数呈明显正相关。结论:MIF在介导急性肺损伤中可能起重要作用,其表达强弱可反映肺组织损害及病变严重程度。

Pulmonary expression of macrophage migration inhibitory factor in oleic-acid-induced acute lung injury rats

AIM: To investigate the pulmonary expresson of macrophage migration inhibitory factor(MIF) in acute lung injury (ALI) rats induced by intravenous injection of oleic acid and its correlation with blood gas change, pulmonary weight index (PWI) and pulmonary pathological injuries.METHODS: ALI rats model were made by injecting oleic acid as the oleic acid group while rats injection with saline solution as control. After injecting oleic acid or saline for six hours, the PaO 2 and PaCO 2 of the left heart and pulmonary weight index were measured. At the same time, by using a microwave-base double immunohistochemistry labeling, the number of MIF , ED 1 (anti-CD68 antibody), ED 1/MIF cell in pulmonary tissue of different groups and their correlation with blood gas and pulmonary weight index were examined. RESULTS: The blood gas parameters of the oleic acid group were far worse than that of the control group (P<0.01). The PWI of the oleic acid group was significantly higher than that of the control group (P<0.01). There was marked upregulation of MIF expression on injured lung tissue. The number of cell expressed MIF , ED 1 and MIF with ED 1 showed a strong positive correlation with PaO 2, PWI and histological changes. CONCLUSION: MIF may play a pivotal role in mediation of progressive lung injuries induced by intravenous oleic acid injection. In addition, the number of cells expressed MIF, especially macrophage, may reflect the severity of lung injury.