T型钙通道阻滞剂对野百合碱诱导大鼠肺动脉高压的影响

Effects of T - type calcium channel inhibitors on monocrotaline - induced pulmonary arterial hypertension in rats

目的探讨T型钙通道阻滞剂ProTx-1、micromolar Ni^2＋及米贝地尔对野百合碱（MCT）诱导大鼠肺动脉高压形成的影响。方法雄性SD大鼠40只，按随机数字表法随机分为5组：正常对照组、MCT组、ProTx-1干预组、micromolar Ni^2＋干预组及米贝地尔干预组，每组8只。实验第28天检测各组大鼠右心室收缩压（RVSP）、右心肥厚指数（RVHI）和肺血管壁占血管总面积百分比（MA%）。采用蛋白印迹法检测增殖细胞核抗原（PCNA）和激活型半胱氨酸天冬氨酸蛋白酶3（Cleaved Caspase-3）在肺动脉平滑肌中表达情况。结果1.MCT组大鼠RVSP、RVHI均高于其他各组，差异均有统计学意义（F＝21.55，P〈0.01；F＝15.63，P〈0.01）；各干预组RVSP、RVHI虽高于正常对照组，但较MCT组明显降低，差异均有统计学意义（均P〈0.05），各干预组间差异无统计学意义。2.MCT组大鼠MA%[（80.24±4.30）%]显著高于正常对照组[（23.43±1.95）%]，差异有统计学意义（P〈0.01），ProTx-1干预组[（60.35±3.83）%]、micromolar Ni^2＋干预组[（62.44±3.81）%]和米贝地尔干预组[（58.66±4.23）%]的MA%虽高于正常对照组，但明显低于MCT组（F＝216.2，P〈0.01）；各干预组MA%比较差异无统计学意义（均P〉0.05）。3.相较于正常对照组，MCT组大鼠肺动脉平滑肌内PCNA蛋白表达明显上调，各干预组PCNA蛋白表达水平均明显低于MCT组。MCT组大鼠Cleaved Caspase-3蛋白表达高于正常对照组，而3个干预组与MCT组比较差异无统计学意义。结论T型钙通道阻滞剂ProTx-1、micromolar Ni^2＋及米贝地尔能有效干预MCT诱导大鼠肺动脉高压形成，并抑制其肺动脉平滑肌细胞的增殖。

Objective To investigate the effects of T - type calcium channel inhibitors （ ProTx - 1, micromolar Ni^2＋ and Mibefradil） on Monocrotaline （MCT） -induced pulmonary arterial hypertension （PAH） in rats. Methods Forty male Spragne - Dawley rats were randomly divided into 5 groups ： normal control group, MCT group, ProTx - 1 group, micromolar Ni^2＋ group and Mibefradil group （8 cases in each group ）. The fight ventricular systolic pressure （RVSP） ,the right ventricular hypertrophy index （RVHI）, and the index of pulmonary vascular remodeling（ MA% ） were measured on day 28 after MCT - treatment. Western blot was used to detect the expression of proliferating cell nuclear antigen（PCNA） and Cleaved Caspase - 3 in pulmonary artery. Results （ 1 ） RVSP and RVHI in MCT group were significandy higher than those in the other 4 groups （ F = 21.55,P 〈 0.01 ;F = 15.63, P 〈 0.01 ）. The two indexes in 3 intervention groups were higher than those in normal control group （ all P 〈 0.05 ）, nevertheless, significantly lower than those in MCT group, and 3 intervention groups showed no significant differences （ all P 〉 0.05 ）. （ 2 ） MA% in normal control group [ （ 23.43 ± 1.95 ） % ] was lower than that in MCT group [ （ 80.42 ±4.30 ） % ], ProTx - 1 group [ （ 60.35± 3.83 ） % ], micromolar Ni^2＋ group [ （ 62.44 ± 3.81 ） % ] and Mibefradil group [ （ 58.66 ±4.23 ） % ] （ F = 216.2, P 〈 0.01 ） ;3 intervention groups showed no significant differences （all P 〉 0.05 ）, however, they were all significantly lower than that in MCT group. （ 3 ） The expression of PCNA in MCT group was higher than that in normal control group,meanwhile,3 intervention groups were significantly lower than that in MCT group. The expression of Cleaved Caspase- 3 in MCT group was higher than that in normal control group, nevertheless ,3 intervention groups showed no significant changes compared with MCT group, respectively. Conclusions T - type calcium channel inhibitors could ameliorate the progression of MCT - PAH in rats, mainly through suppressing the proliferation of pulmonary artery smooth muscle cells.