灯盏花素对低氧大鼠肺动脉压和肺小动脉Rho激酶的影响

The effect of breviscapine on the pulmonary arterial pressure and the expression of Rho-kinase in pulmonary arterioles of hypoxic rats

目的观察灯盏花素对低氧大鼠肺动脉压、肺小动脉Rho激酶ROCKI和ROCKⅡ及Rho激酶mRNA的影响，探讨灯盏花素预防低氧性肺动脉高压的作用和机制。方法将18只健康雄性SD大鼠分为健康组、低氧组和灯盏花素预防组。以常压低氧法复制肺动脉高压模型，以微导管法测定平均肺动脉压（mPAP）。分离大鼠心脏，测量右心室（RV）及左心室加室间隔（LV＋S）的重量，以RV／（LV＋S）代表右心肥厚指数。应用图像分析技术测定肺小动脉管壁厚度占外径的百分比和管壁面积占总面积的百分比，反映肺血管重塑情况。应用免疫组化法测定肺小动脉Rho激酶蛋白的表达，原位杂交法测定肺小动脉Rho激酶mRNA的表达。结果低氧组大鼠mPAP为（27．3±5．0）mmHg（1mmHg=0．133kPa），明显高于健康组的（16．0±0．6）mmHg（t=6．74，P〈0．05），灯盏花素预防组mPAP为（19．83±1．47）mmHg，明显低于低氧组（t=4．28，P〈0．05）；低氧组RV／（LV＋S）及肺小动脉厚度指数明显高于健康组（t=3．43，P〈0．05），灯盏花素预防组低于低氧组（t=2．39，P〈0．05）；低氧组ROCKⅠ和ROCKⅡ免疫组织化学阳性染色（1．29±0．08和1．63±0．24）明显高于健康组（1．17±0．09和1．30±0．16），灯盏花素预防组（1．18±0．10和1．30±0．12）明显低于低氧组（t值分别为3．96，5．85，3．90，5．82，均P〈0．05）；低氧组ROCKImRNA和ROCKIImRNA原位杂交阳性染色（分别为1．37±0．13和1．59±0.31）明显高于健康组（1．22±0．09和1．21±0．15），灯盏花素预防组（1．23±0．13和1．22±0．06）明显低于低氧组（t值分别为4．00，6．02，3．94，5．83，均P〈0．05）。结论灯盏花素具有明显预防低氧性肺动脉高压和降低Rho激酶及Rho激酶mRNA的作用。

Objective To observe the effect of breviscapine on the pulmonary artery pressure and the Rho-kinase and Rho-kinase mRNA in pulmonary arterioles of rats treated with hypoxia, and therefore to explore the mechanisms of breviscapine on hypoxie pulmonary hypertension. Methods Eighteen adult male SD rats were randomly divided into 3 groups. One group was exposed to air （normal group）, the second group was exposed to isobaric hypoxia for 3 weeks （hypoxic group ）, and the third group was exposed to hypoxia for 3 weeks and treated with breviscapine （preventive group）. Cardiac catheterization was used to measure the mean pulmonary arterial pressure （mPAP）. The heart was isolated, and the right ventricle （ RV）, left ventricle plus ventricular septum （ LV ＋ S） were weighed to calculate the ratio RV/（ LV ＋ S ）. The ratio of vascular wall thickness/vascular external diameter （ WT% ） and the ratio of vascular wall area/ total vascular area （WA%） were measured by image analysis. The quantity of Rho-kinase and Rho-kinase mRNA in rat pulmonary arterioles were determined by immunohistochemistry and in situ hybridization respectively. Results The rnPAP in the preventive group [ （ 19. 83 ±1.47 ） mm Hg, 1 mm Hg = 0. 133 kPa] was significantly lower than that of the hypoxic group [ （27. 3±5.0） mm Hg] ,t =4. 28, P 〈0. 05. The RV/（ LV ＋ S） in the preventive group （ 0.29 ± 0.03 ） was significantly lower than that in the hypoxic group （0. 34 ± 0.05, t = 2. 39, P 〈 0. 05）. The WT% and WA% in the preventive group （25 ± 5 and 45 ±5, respectively） were significantly lower than those in the hypoxic group （36 ± 12 and 59 ± 13, respectively,t = a. 89, 5. 89, P 〈 0.05）. The positive staining of ROCK Ⅰ and ROCK Ⅱ on pulmonary arterioles in the preventive group （1.18 ± 0. 10 and i. 30 ± 0. 12, respectively） were significantly lower than those in the hypoxic group （ 1.29 ± 0.08 and 1.63 ± 0. 24, respectively, t = 3.90, 5.82, P 〈 0. 05 ）. The positive staining of ROCK Ⅰ mRNA and ROCK Ⅱ mRNA in the preventive group （ 1.23 ± 0. 13 and 1.22 ± 0. 06, respectively） were significantly lower than those in the hypoxic group （ 1.37 ± 0. 13 and 1.59 ± 0. 31, respectively, t = 3.94, 5.83, P 〈 0. 05 ）. Conclusion Breviscapine was shown to prevent hypoxic pulmonary hypertension and decrease Rho-kinase and Rho-kianse mRNA.