MMP-9与TIMP-1在油酸制备大鼠急性肺损伤模型中的表达特点与临床意义探讨

目的检测油酸制备大鼠急性肺损伤模型血浆及肺组织基质金属蛋白酶9(matrix metalloproteinases9,MMP-9)及组织基质金属蛋白酶抑制因子-1(tissue matrix metalloproteinase inhibitor-1,TIMP-1)含量,分析MMP-9及TIMP-1的表达特点及临床意义。方法雄性SD大鼠24只分为3组:空白对照组(n=8)、油酸造模2h组(n=8)、油酸造模6h组(n=8)。空白对照组大鼠尾静脉注射0.9%氯化钠注射液(0.1mL/kg)6h后观察。油酸造模组大鼠尾静脉缓慢注射油酸(OA,0.1mL/kg)2h、6h后观察,以复制油酸诱导大鼠急性肺损伤模型。观察及检测指标为光镜下肺组织病理形态学变化、动脉血氧分压(PaO2)、肺湿/干质量比(W/D)、血浆和肺组织MMP-9和TIMP-1含量。结果①光镜下,与空白对照组比较,油酸造模组大鼠明显可见肺间质及肺泡水肿,肺泡腔内有浆液性渗出物及大量炎性反应细胞、红细胞渗出,部分肺间隔增厚,呈均匀红染的"透明膜"样改变;②与空白对照组比较,2h及6h时,油酸造模组PaO2明显降低(P<0.001),W/D明显升高(P<0.05);③与空白对照组比较,2h及6h时,油酸造模组血浆和肺匀浆MMP-9含量明显升高(P<0.001),TIMP-1含量明显降低(P<0.05,P<0.01或P<0.001);2h与6h比较,油酸造模组血浆和肺匀浆MMP-9及TIMP-1含量无明显变化(P>0.05);④2h及6h时,血浆MMP-9与肺匀浆MMP-9含量呈高度正相关(r=0.999,P<0.001或r=0.885,P<0.05),血浆TIMP-1与肺匀浆TIMP-1含量呈高度正相关(r=0.850,P<0.001或r=0.800,P<0.05)。结论油酸制备急性肺损伤大鼠模型血浆、肺匀浆MMP-9含量明显升高,TIMP-1含量明显降低,两者随发病时间延长无明显变化。血浆MMP-9、TIMP-1与肺匀浆MMP-9、TIMP-1含量高度正相关,检测血浆MMP-9、TIMP-1有助于急性肺损伤的病理诊断和治疗,从而为临床急性肺损伤的诊断、治疗及预后提供简单、可行、准确的检测方法和途径。

Expression and Clinical Significance of Matrix Metalloproteinase-9 and Tissue Matrix Metalloproteinase Inhibitor-1 in Acute Lung Injury Model in Rats Induced by Oleic Acid

Objective To detect the levels of matrix metalloproteinases 9(MMP-9) and tissue matrix metalloproteinase inhibitor-1(TIMP-1) in plasma and lung homogenates of model rats with acute lung injury(ALI) induced by oleic acid,and to analyze the expression characteristics and clinical significance of MMP-9 and TIMP-1.Methods Twenty-four male SD rats were randomly divided into three groups:normal control group(n=8),oleic acid model control group for 2 h(n=8) and oleic acid model control group for 6 h(n=8).Oleic acid(OA,0.1 mL/kg) was given with slow tail vein injection to the rats in oleic acid model control group,while the rats in normal control group were injected with sodium chloride(0.1 mL/kg) solution.The observation and measurement indicators included the pathological changes of lung under light microscope,arterial partial pressure of oxygen(PaO₂),lung wet/dry weight ratio(W/D),the levels of MMP-9 and TIMP-1 in plasma and lung homogenates.Results ① Histomorphology of lung:Compared with normal control group,significant pathological changes of lung were seen in oleic acid model control group,including pulmonary interstitial and alveolar edema,a large amount of serous exudation,inflammatory cells,red blood cell leakage in alveolar cavity.Part of the pulmonary interstitial thickening were uniformly stained "transparent membrane" pattern.② Compared with normal control group,as 2 h and 6 h,PaO₂ of rats in oleic acid model group decreased significantly(P<0.001) while W/D increased significantly(P<0.05).③ Compared with normal control group,as 2 h and 6 h model groups,the level of MMP-9 in plasma and lung homogenates increased significantly(P<0.001) while TIMP-1 in plasma and lung homogenates decreased significantly(P<0.05,P<0.01 or P<0.001);when 2 h models were compared with 6 h models,there was no significant change(P>0.05) in MMP-9 and TIMP-1 in plasma and lung homogenate.④ In both 2 h and 6 h models,there was a highly positive correlation(r=0.999,P<0.001 or r=0.885,P<0.05) between MMP-9 in plasma and that in lung homogenate,meanwhile,there was also highly positive correlation(r=0.850,P <0.001 or r=0.800,P<0.05) between TIMP-1 in plasma with that in lung homogenate.Conclusion The level of MMP-9 in plasma and lung homogenate increased significantly while that of TIMP-1 decreased significantly in rats in oleic acid model control group,and there were no significant changes of MMP-9 and TIMP-1 with the development of ALI from 2 h to 6 h.There were highly positive correlation between plasma MMP-9,TIMP-1 and those in lung homogenates,which suggest that the detection of plasma MMP-9 and TIMP-1 may contribute to the diagnosis and treatment of ALI.