雌激素膜快速效应对兔血管平滑肌细胞iNOS快速激活的影响  

Membrane estrogen receptor mediates the rapid activation of iNOS by estrogen in rabbit vascular smooth muscle cells

作　　者：刘海梅[1] 徐进文[1] 许研 赵晓峰[3] 王庭槐[3] 

机构地区：[1]广州中医药大学生理学教研室,广东广州510006 [2]广州市第11人民医院心内科,广东广州510530 [3]中山大学中山医学院生理学教研室,广东广州510080

出　　处：《心脏杂志》2015年第6期629-633,共5页Chinese Heart Journal

基　　金：国家自然科学基金项目资助(30440028;81202186)

摘　　要：目的探讨17β-雌二醇(17β-estradiol,E2)通过快速激活诱导型一氧化氮合成酶(iNOS)的活性,调节细胞外信号调节激酶(mitogen-activated protein kinase,p42/44 MAPK)表达抑制血管平滑肌细胞(vascular smooth muscle cells,VSMCs)增殖的机制。方法在培养的VSMCs的基础上,采用放射免疫测定法(RIA)和Western blot检测E2预处理前后胎牛血清(fetal calf serum,FCS)对VSMCs中诱导型i NOS的活性及磷酸化p42/44 MAPK蛋白和p42/44MAPK总蛋白表达的影响。采用比色法检测E2预处理后VSMCs中NO含量的变化。结果 E2预处理5 min,即可逆转FCS诱导的iNOS活性下降,此效应在E2预处理15 min时达到高峰,处理30 min后此效应减弱。基因转录抑制剂放线菌素D(actinomycin D,Act D)预处理后对此过程无影响,而三苯氧胺预处理可明显逆转E2诱导的iNOS活性增加。比色法检测上清液中NO的含量显示,E2预处理15 min,NO的含量明显增加。Western blot的结果显示,E2预处理15 min,可明显抑制磷酸化p42/44 MAPK蛋白的表达,而对总p42/44 MAPK蛋白的表达无影响。NO合酶(NOS)抑制剂L-硝基左旋精氨酸甲酯(L-NAME)预处理,可逆转E2诱导的磷酸化p42/44 MAPK的表达下降。结论 E2可通过快速激活i NOS增加NO释放,下调磷酸化p42/44 MAPK的活性,抑制VSMCs增殖。AIM To investigate the non-genomic effect on inhibition of the proliferation of vascular smooth cells （VSMCs） via activation of iNOS and mitogen-activated protein kinase （p42/44MAPK） by 17β-estradiol. METHODS iNOS activation was determined by radioimmunoassay. Expressions of iNOS, p42/44 MAPK and p42/44 MAPK phosphorylation were measured by Western blot and expression of NO content was detected by colorimetric method. RESULTS In cultured VSMCs, activation of iNOS began to increase after pretreatment with estrogen for 5 min, and the maximum effect took place at 15 min and rapidly reverted thereafter. The effect of E2 on iNOS activation was not affected by actinomycin D but was obviously inhibited by tamoxifen. At the same time, NO production increased significantly after treatment with 17β-estradiol within 15 min. Compared with fetal calf serum, E2 pretreatment of VSMCs for 15 min decreased p42/44MAPK activity and this effect was blocked by L-NAME. CONCLUSION 17β-estradiol rapidly upregulates iNOS activation and NO production and downregulates p42/44 MAPK activation to inhibit VSMC proliferation through a non-genomic effect.

关 键 词：17Β-雌二醇 血管平滑肌细胞 一氧化氮合酶 细胞外信号调节激酶 兔 

分 类 号：R977.12[医药卫生—药品]