甲基泼尼松龙对油酸制备大鼠急性肺损伤模型干预治疗作用的研究

Intervention Effects of Methylprednisolone to Acute Lung Injury Model of Rats Induced by Oleic Acid

目的探讨及验证甲基泼尼松龙对油酸诱导大鼠急性肺损伤模型的治疗作用。方法雄性SD大鼠30只随机分为3组:空白对照组(n=6)、油酸造模组(n=12)、甲基泼尼松龙组(n=12)。对油酸制备大鼠急性肺损伤模型的基础上,对急性肺损伤大鼠进行糖皮质激素干预实验,以大体标本病理改变、光镜下半定量肺损伤评分(IQA)、肺湿/干重比(W/D)、动脉血氧分压(PaO_2)、血浆及肺组织SOD和MDA为观察检测指标,同时检测其他相关生化指标(血浆及肺组织MMP-9和TIMP-1),以期对糖皮质激素治疗的过程进行客观评估,进而探讨其作用途径和机制,为探讨ALI的药物干预研究提供实验依据。结果大体标本病理改变:油酸造模组较甲基泼尼松龙组双肺体积明显增大,肺外周可见片状出血及充血水肿。光镜下,油酸造模组大鼠的肺部组织较甲基泼尼松龙组存在明显病理学改变,可见肺间质和肺泡水肿,肺泡腔内渗出浆液性物质及大量的炎性细胞和红细胞,部分肺间隔增厚,呈现均匀红染的透明膜样改变。动脉血氧分压(PaO_2):与空白对照组比,2、6h时,油酸造模组PaO_2明显下降(P<0.01),6h时甲基泼尼松龙组PaO_2有升高(P<0.05)。肺湿干重比(W/D):与空白对照组比,2、6h时,油酸造模组W/D明显升高(P=0.000),与油酸造模组比,2、6h时,甲基泼尼松龙组有明显下降(P<0.05)。光镜下半定量肺损伤评分IQA:与空白对照组比,2h、6h时,油酸造模组IQA明显升高(P<0.01)。甲基泼尼松龙组与造模组对比,IQA降低(P<0.05)。甲基泼尼松龙组与造模组对比血浆及肺组织SOD含量明显升高(P<0.01)。甲基泼尼松龙组与造模组对比血浆及肺组织MDA明显降低(P<0.05)。甲基泼尼松龙组与造模组对比血浆及肺组织MMP-9含量降低(P<0.05)。与油酸造模组比较,甲基泼尼松龙组血浆及肺组织TIMP-1含量升高(P<0.05)。结论甲基泼尼松龙干预治疗对急性肺损伤模型大鼠有明显的疗效,其可能部分通过对急性肺损伤大鼠血浆和肺组织SOD、MDA、MMP-9和TIMP-1的调节,来改善动脉血PaO_2、W/D、IQA,而发挥抗炎、抗渗出作用,从而为临床防治急性肺损伤提供可能的途径和思路。

Objective To observe the intervention effects of methylprednisolone （MPred） to acute lung injury（ALl） model of rats induced by oleic acid. Methods Thirty of Sprague - Dawley rats were randomly divided into three groups which were normal control group （NC, n =6）, oleic acid model group （n = 12）, and MPred group （n = 12）. Rats were injected with oleic acid at dose of 0. ling/ kg via caudal vein and then ALl model was established. The rats of NC group were injected with 0, lmg/kg of normal saline instead of ole- ic acid. In NC group rats were sacrificed by blood collection at 6h after NS injection. Blood samples and tissues were collected and stored freezing. Samples of the other groups were collected at 2h and 6h after the last treatment. The observation indexes are histomorphology of lung tissue, the wet and dry weight of lung （W/D） , index of quantitative assessment （IQA） score, partial pressure of oxygen in artery （PaO=） , and SOD,MDA, MMP -9 and TIMP - 1 levels in the blood plasma and lung tissue. Results Lung surface hyperemia relieved obviously and pink secretion from trachea of rats in MPred group decreased compared with oleic acid model group. In light microseope, compared with oleie acid model group, effusion of inflammatory cell in alveolar space of rats in MPred group eased. W/D of rats in oleie acid model group advanced obviously compared with that in NC group, W/D of rats in medrol group lowered obviously compared with that in oleic acid model group. IQA scores of rats in oleic acid model group advanced obviously compared with that in NC group, IQA score of rats in MPred group lowered obviously compared with that in oleic acid model group. PaO2 of rats in oleic acid model group lowered obvi- ously compared with that in NC group, PaO2 of rats in MPred group advanced obviously compared with that in oleic acid model group. The level of SOD in plasma and lung tissue of rats in oleic acid model group lowered obviously compared with that in NC group, SOD level in plasma and lung tissue of rats in MPred group advanced obviously compared with that in oleic acid model group. The level of MDA in plas- ma and lung tissue of rats in oleic acid model group lowered obviously compared with that in NC group, MDA in plasma and lung tissue of rats in MPred group advanced obviously compared with that in oleic acid model group. Compared with the NC group, the level of MMP - 9 in the plasma and lung tissue of oleic acid induced ALI rats increased and TIMP - 1 levels decreased significantly. The level of MMP - 9 in the plasma of rats decreased and TIMP - 1 level increased significantly in MPred group at 2h and 6h. Conclusion MPred can im- prove lung pathological injury, increase PaO2 level, decrease lung W/D ratio and IQA scores by modulating the level or activity of the SOD and MDA and MMP -9 and TIMP - 1 in the plasma and lung tissues. It is speculated that the effects of anti - inflammation and anti - exudation of sodium aescinate may due to affecting on oxidative stress response as well as the decomposition and remodeling of extra- cellular matrix during inflammatory lung injury of acute lung injury rats.