川芎嗪对慢性低O_2高CO_2大鼠肺动脉结构型和诱导型一氧化氮合酶及其基因表达的影响

Effect of ligustrazine on ceNOS mRNA and iNOS mRNA in pulmonary arteries in chronic hypoxic hypercapnic rats

目的 探讨川芎嗪对慢性低O2 高CO2 性肺动脉高压的预防作用及其作用机制。方法 将Sprague Dawley大鼠分为正常对照组 (A组 ) ,4wk低O2 高CO2 组 (B组 ) ,4wk低O2 高CO2 +川芎嗪组 (C组 ) ,采用透射电镜、图像分析、免疫组化、原位杂交等方法 ,研究川芎嗪对慢性低O2 高CO2 大鼠肺动脉平均压 (mPAP)、颈动脉平均压 (mCAP)、血清一氧化氮 (NO)、肺动脉显微和超微结构、肺动脉结构型一氧化氮合酶 (ceNOS)和诱导型一氧化氮合酶 (iNOS)及其基因表达的影响。结果 ①B组肺动脉平均压 (mPAP)明显高于A组 (t=8 190 ,P <0 0 1) ,C组mPAP明显低于B组 (t=4 894,P <0 0 1) ,三组间mCAP差异无显著性 (P >0 0 5 ) ,血清NO浓度C组与B组相比明显增高 (t =2 196 ,P <0 0 5 ) ;②光镜下 ,肺细小动脉管壁面积 /管总面积比值(WA/TA)、肺细小动脉中膜平滑肌细胞核密度 (SMC)C组较B组明显降低 (t=4 815 ,P <0 0 1) ;电镜下 ,C组大鼠肺细小动脉中膜平滑肌细胞和胶原纤维增生较B组明显减轻 ;③免疫组化发现 ,C组肺细小动脉ceNOS的平均吸光度值较B组明显增高 (t =10 5 5 ,P <0 0 1) ;C组肺细小动脉iNOS的平均吸光度值与B组相比差异无显著性 (P >0 0 5 ) ;④原位杂交发现 ,C组肺细小动脉ceNOSmRNA平均吸光度值较B组明显?

AIM To investigate the effect of ligustrazine on mean pulmonary arterial pressure(mPAP) and nitric oxide synthase (NOS) in arterioles in chronic hypoxic hypercapnic rats METHODS Thirty rats were randomly divided into three groups: control group(A),hypoxic hypercapnic group(B), hypoxic hypercapnic+ ligustrazine (lig) group (C). Constitutive endothelial NOS (ceNOS) and inducible NOS (iNOS) were observed in arterioles of rats using the technique of immunohistochemistry, ceNOS mRNA and iNOS mRNA were observed by the technique of hybridization in situ RESULTS ① mPAP was significantly higher in rats of B group than that of A group(P<001) and it was much lower in rats of C group than that of B group (P<001), Differences of mCAP were not significant in three groups (P>005) ; Serum nitric oxide (NO)concentration was significantly higher in rats of C group than that of B group (P<005) ; ②Light microscopy showed WA/TA (vessel wall area/total area) and SMC (the density of medial smooth muscle cells) were significantly lower in rats of C group than that of B group (P<001). Electron microscopy showed that ligustrazine could inhibit the proliferation of smooth muscle cells and collageous fibers of pulmonary arterioles in chronic hypoxic hypercapnic rats③Immunohistochemistry showed the average value of integral light density(LD) of ceNOS in pulmonary arterioles was significantly higher in rats of C group than that of B group(P<001), difference of LD of iNOS in pulmonary arterioles was not significant between B group and C group (P>005); ④Hybridization in situ showed LD of ceNOS mRNA in pulmonary arterioles was significantly higher in rats of C group than that of B group (P<001). Difference of LD of iNOS mRNA in pulmonary arterioles was not significant between B group and C group(P>005) CONCLUSION Ligustrazine can inhibit pulmonary hypertension and the proliferation of smooth muscle cells and collagenous fibers of pulmonary arterioles in chronic hypoxic hypercapnic rats by incresing the expression of ceNOS and ceNOS mRNA in pulmonary arterioles