肾上腺髓质素调节诱导型一氧化氮合酶对缺氧肺动脉平滑肌细胞增殖和凋亡的影响  

EFFECTS OF ADRENOMEDULLIN REGULATING INDUCIBLE NITRIC OXIDE SYNTHASE ON PROLIFERATION AND APOPTOSIS IN HYPOXIC PULMONARY ARTERY SMOOTH MUSCLE CELLS

作　　者：李炽观 戴爱国 黄翠萍 

机构地区：[1]湖南省老年医院 [2]湖南郴州第一人民医院呼吸内科,湖南郴州423000

出　　处：《中国应用生理学杂志》2005年第2期187-191,共5页Chinese Journal of Applied Physiology

基　　金：国家自然科学基金资助(30270581);湖南省教育厅重点科研基金资助(02A047);湖南省自然科学基金资助(99JJY20033)

摘　　要：目的:探讨缺氧对肺动脉平滑肌细胞(PASMC)增殖和凋亡的影响以及诱导型一氧化氮合酶(iNOS)的蛋白表达变化及肾上腺髓质素(ADM)在缺氧影响PASMC增殖和凋亡中的作用与意义。方法:离体缺氧培养大鼠PASMC,采用MTT比色法和PCNA的免疫组化法测定细胞增殖反应,采用流式细胞仪法检测细胞凋亡情况,采用Westenblot蛋白印迹法检测iNOS的蛋白表达。结果:①MTT法发现,缺氧24h组的A值明显高于常氧组(P<0.01),而缺氧+ADM组明显低于缺氧组(P<0.01),与常氧组比较差别无显著性(P>0.05),缺氧+L NAME组A值明显高于缺氧组和常氧组(P<0.01)。②免疫组化法发现,常氧组PCNA呈弱阳性表达,而缺氧24h组PCNA呈阳性表达(P<0.01)。ADM明显抑制了缺氧24h组PCNA的表达(P<0.01);而L NAME则促进了缺氧24h组PCNA的表达(P<0.01)。③流式细胞仪分析发现,常氧组、缺氧组、缺氧+ADM组、缺氧+L NAME组,在缺氧培养24h后,其凋亡指数比较差别无显著性(P均>0.05)。④Westenblot发现常氧组大鼠PASMC见少量iNOS表达,缺氧4h后,表达明显增多(P<0.01),8h,24h持续高表达(P<0.01);L NAME对iNOS蛋白的表达没有影响。ADM促进iNOS蛋白的表达。结论:①缺氧能促进肺动脉平滑肌细胞低氧性增殖,对肺动脉平滑肌细胞的凋亡无影响。Aim: To investigate the effects of hypoxia on the proliferation and apoptosis of PASMC, to evaluate the role of iNOS protein expression and ADM on the hypoxic pulmonary hypertension(HPH) pathogenesis.Methods: To culture rat pulmonary artery smooth muscle cell(PASMC), cultured PASMC cells were grouped into: normoxic group; hypoxic group; hypoxia+L-NAME group; hypoxia+ADM group.Proliferation of PASMC were investigated by MTT and PCNA. Apoptosis of PASMC were examed by flow-cytometry.Westen blot was used to measure protein expression of iNOS induced by hypoxia. Results: ①By MTT, the value of 24 h hypoxia was significantly higher than that in the normoxic group(P<0.01), the value of the hypoxia+ ADM was significantly lower than that in hypoxia group, the value of the hypoxia+L-NAME was significantly higher than those of hypoxic group and normoxic group(P<0.01). ② By immunohistochemstry, PCNA was poorly positive in PASMC, whereas positive after 24 h hypoxia(P<(0.01)), ADM inhibited the expression of PCNA significantly(P<0.01), whereas L-NAME increased the expression of PCNA signi-(ficantly)(P<0.01).③ By FCM, apoptosis index was not significantly different between the normoxic group, hypoxic group, hypoxia+L-NAME and hypoxia+ADM(P>0.05). ④ By Western blot, iNOS expression was poorly positive in control group, positive after 4 h hypoxia(P<0.01), increasing as the hypoxia environment continued(P<0.01). L-NAME had no effect on iNOS protein, ADM promoted iNOS expression(P<0.01). Conclusion: ① Hypoxia stimulates the proliferation of PASMC, and has no obvious effects on the apoptosis of PASMC.② Hypoxia induces the expression of iNOS, ADM can increase expression of iNOS, ADM and (iNOS) plays a role of protection in HPH pathogenesis.

关 键 词：平滑肌细胞 肺动脉 增殖 凋亡 诱导型一氧化氮舍酶 肾上腺髓质素 缺氧 

分 类 号：R332[医药卫生—人体生理学]