血浆纤溶酶原激活物抑制剂-1抑制剂对大鼠创伤性股骨头坏死程度的影响

Effect of plasminogen activator inhibitor-1 inhibitors on the severity of traumatic femoral head necrosis in rats

目的在大鼠创伤性股骨头坏死模型中探究血浆纤溶酶原激活物抑制剂-1(plasminogen activator inhibitor-1,PAI-1)抑制剂对血浆活性PAI-1含量以及对术后股骨头坏死程度的影响。方法构建大鼠创伤性股骨头坏死模型60只,并随机分为PAI-1抑制剂组、PAI-1组和空白对照组(每组20只)。PAI-1抑制剂组大鼠在术后6 h腹腔注射PAI-1抑制剂毛两面针素(1 mg/kg)并在之后予以PAI-1抑制剂Tiplaxtinin灌胃4周[2 mg/(kg·d)]。PAI-1组大鼠在术后6 h开始每3 d给予1次外源性PAI-1(2.5 nmol/kg)腹腔注射。空白对照组大鼠注射相同剂量生理盐水。应用ELISA方法分别在术前、术后6 h、12 h、24 h和4周时检测各组大鼠血浆活性PAI-1含量;实验结束时取各组大鼠右侧股骨头,采用显微CT和HE染色检查评估股骨头坏死情况。结果PAI-1抑制剂组使用PAI-1抑制剂后2只大鼠出现术后出血,空白对照组1只大鼠术后出现感染死亡。与术前相比,空白对照组和PAI-1抑制剂组术后6 h血浆活性PAI-1含量明显升高,且随时间延长血浆活性PAI-1含量显著下降(P<0.01);PAI-1组血浆活性PAI-1含量在术后6 h亦明显升高(P<0.01),但后期血浆活性PAI-1含量无显著降低趋势(P>0.05);术前与术后6 h的血浆活性PAI-1含量结果显示,与空白对照组相比,PAI-1抑制剂组、PAI-1组差异无明显统计学意义(P>0.05);术后12 h、24 h及术后4周时的血浆活性PAI-1含量结果显示,与空白对照组相比,PAI-1抑制剂组显著降低,PAI-1组显著升高(P<0.01);与PAI-1抑制剂组相比,PAI-1组在术后12 h、24 h及术后4周时的血浆活性PAI-1含量显著升高(P<0.01)。股骨头坏死评价指标方面,与空白对照组相比,PAI-1抑制剂组骨体积分数和骨小梁厚度显著升高(P<0.05),骨小梁分离度、空骨陷窝率和脂肪组织面积显著降低(P<0.05),PAI-1组骨体积分数和骨小梁厚度显著降低(P<0.05),骨小梁分离度、空骨陷窝率和脂肪组织面积显著升高(P<0.05);与PAI-1抑制剂组相比,PAI-1组骨体积分数和骨小梁厚度显著降低(P<0.05),骨小梁分离度、空骨陷窝率和脂肪组织面积显著升高(P<0.05)。结论大鼠创伤性股骨头坏死模型中,血浆活性PAI-1是创伤性骨头坏死的重要风险因素之一,且使用PAI-1抑制剂可以有效降低大鼠血浆活性PAI-1含量,降低大鼠创伤性股骨头坏死程度。

Objective To investigate the effect of plasminogen activator inhibitor-1(PAI-1)inhibitors on plasma levels of active PAI-1 and the severity of postoperative femoral head necrosis in a rat model of traumatic femoral head necrosis.Methods A total of 60 rats were used to establish a rat model of traumatic femoral head necrosis and were randomly divided into 3 groups:PAI-1 inhibitor group,PAI-1 group,and blank control group(20 rats in each group).In the PAI-1 inhibitor group,rats were intraperitoneally injected with the PAI-1 inhibitor tiplaxtinin(1 mg/kg)6 hours after surgery,followed by oral administration of Tiplaxtinin[2 mg/(kg?d)]for 4 weeks.In the PAI-1 group,rats received an intraperitoneal injection of exogenous PAI-1(2.5 nmol/kg)every 3 days after surgery.The blank control group received an equivalent volume of normal saline.Plasma levels of active PAI-1 were measured using an ELISA method at preoperative,6 hours,12 hours,24 hours,and 4 weeks postoperatively.At the end of the experiment,the right femoral heads of the rats in each group were evaluated for femoral head necrosis using micro-CT and H&E staining.Results In the PAI-1 inhibitor group,two rats experienced postoperative bleeding,and in the blank control group,one rat had an infection.Plasma levels of active PAI-1 in the blank control group and the PAI-1 inhibitor group were significantly elevated at 6 hours postoperatively and then significantly decreased over time(P<0.01).In the PAI-1 group,plasma levels of active PAI-1 were significantly increased at 6 hours postoperatively(P<0.01),but there was no significant decrease in plasma levels of active PAI-1 in the later stages(P>0.05).There were no significant intergroup differences in plasma levels of active PAI-1 between the PAI-1 inhibitor group and the PAI-1 group at 6 hours postoperatively compared to the blank control group(P>0.05).However,at 12 hours,24 hours,and 4 weeks postoperatively,plasma levels of active PAI-1 were significantly increased in the PAI-1 group compared to the blank control group,while they were significantly decreased in the PAI-1 inhibitor group(P<0.01).Regarding the evaluation of femoral head necrosis,compared to the blank control group,the PAI-1 inhibitor group showed significantly increased bone volume fraction and trabecular thickness(P<0.05)and significantly decreased trabecular separation,bone marrow cavity rate,and adipose tissue area(P<0.05).The PAI-1 group exhibited significantly decreased bone volume fraction and trabecular thickness(P<0.05)and significantly increased trabecular separation,bone marrow cavity rate,and adipose tissue area(P<0.05)compared to the blank control group.When comparing the PAI-1 inhibitor group to the PAI-1 group,the former showed significantly decreased bone volume fraction and trabecular thickness(P<0.05)and significantly increased trabecular separation,bone marrow cavity rate,and adipose tissue area(P<0.05).ConclusionIn a rat model of traumatic femoral head necrosis,plasma levels of active PAI-1 were found to be an important risk factor for traumatic bone necrosis.The use of PAI-1 inhibitors effectively reduced plasma levels of active PAI-1 and the severity of traumatic femoral head necrosis in rats.