卡托普利及氯沙坦干预大鼠肺动脉高压与MMP-2、MMP-9、TIMP-1表达的关系

Changes of MMP-2,9 and TIMP-1 Expressions in Rats with Pulmonary Arterial Hypertension after Captopril and Losartan Interventions

目的探讨卡托普利及氯沙坦在大鼠肺动脉高压中对基质金属蛋白酶2、9(MMP-2、9)及其组织抑制物TIMP-1调节的影响,以了解卡托普利及氯沙坦治疗肺动脉高压可能的作用机制。方法40只雄性SD大鼠,随机分为正常对照组、左肺切除+野百合硷组(肺动脉高压模型组)、卡托普利10 mg/(kg.d)干预组、氯沙坦15mg/(kg.d)干预组,每组10只。35 d后观察各组的平均肺动脉压(mPAP)、心室质量即右心室/(左心室+室间膈)、肺小动脉中膜厚度和新生内膜形成以及无肌型小动脉肌化程度的变化;应用免疫组化和实时荧光定量PCR(FQ-PCR)检测MMP-2、9、TIMP-1在肺组织中的表达;应用明胶酶谱法检测MMP-2、9的活性。结果肺动脉高压模型组肺小动脉有新生内膜形成,该组mPAP、心室质量、肺小动脉厚度、小动脉肌化程度、MMP-2、9和TIMP-1表达均高于其它组(P<0.05);卡托普利和氯沙坦组上述各指标较模型组均下降(P<0.05)。结论卡托普利及氯沙坦干预肺高压的机制之一是调节肺组织MMP-2、9和TIMP-1表达,从而缓解肺动脉高压和肺血管重构的形成。

Objective To determine the effect of captopril and losartan on the expressions of matrix metalloproteinase-2,9 （MMP-2,9） and metalloproteinase-1 （TIMP-1） in rats with pulmonary arterial hypertension, and the mechanisms of captopril and losartan in intervening the development of pulmonary arterial hypertension. Methods Forty male Spraque-Dawley rats were divided into 4 groups randomly： pulmonary arterial hypertension （created by pneumonectomy plus MCT injection） model group（PAH Model）, PAH model treated with captopril [PAH＋Cap 10 mg/（kg · d）], losartan group[PAH＋Los 15 mg/（kg · d）] and normal control group（Control）. The mPAP, weight ratio of RV to LV＋S, neointima formation, relative thickness of small pulmonary arteries, and degree of muscularization of non-muscular arterioles were measured at day 35. The expression of SM-α-actin in the PASMC was determined by immunochemistry stain. The expressions of MMP-2, 9, TIMP-1 and MMP-2, 9, TIMP-1 mRNA in the pulmonary tissues were determined by immunohistochemistry and FQ-PCR respectively. The enzymatic activity of MMP-2, 9 was measured by Gelatin zymography. Results Pneumonectomy plus MCT injection induced severe pulmonary arterial hypertension characterized by neointimal formation. Captopril or losartan suppressed the increase of mPAP, right ventricle weight, thickness of small pulmonary arteries and muscularization of peripheral pulmonary arterioles in the rats with PAH （P〈0.05）. The PAH model group had higher expressions of MMP-2, 9, TIMP-1 mRNA and enzymatic activity of MMP-2, 9 in lung tissue than the other groups （P〈0.05）. Captopril intervention had similar effects as losartan intervention. Conclusion The captopril and losartan induced attenuation of PAH and pulmonary vascular remodeling is likely to be associated with the regulation of the expressions of MMP-2, 9, TIMP-1.