心钠素对高血压大鼠动脉平滑肌细胞离子泵活性和基因表达的影响  

Effects of ANP upon ion pump activity and gene expression in aortic smooth muscle cells from spontaneously hypertensive rats

作　　者：张贵海[1] 商黔惠[1] 姜黔峰[1] 吴泽兵[1] 刘祖林 万卫红 

机构地区：[1]遵义医学院临床医学研究所遵义医学院附属医院心内科,贵州563003 [2]细胞工程重点实验室

出　　处：《中华医学杂志》2009年第40期2862-2866,共5页National Medical Journal of China

基　　金：基金项目：贵州省科学技术基金[（2002）3013];贵州省优秀科技教育人才省长专项资金[（2005）239]

摘　　要：目的探讨心钠素（ANP）对自发性高血压大鼠（SHR）动脉平滑肌细胞膜（ASMC）Na^＋，K^＋-ATP酶、Ca^2＋-ATP酶活性及Na^＋，K^＋-ATP酶α1亚单位、Ca^2＋-ATP酶亚型1（PMCA1）mRNA表达的影响。方法对SHR大鼠，予不同浓度ANP和血管紧张素Ⅱ（AngⅡ）干预，通过放射免疫、生化酶学和逆转录．聚合酶链反应等方法，检测ASMC的ANP、AngⅡ含量，ATP酶活性及其mRNA表达变化并设WKY大鼠为对照。结果SHR大鼠ANP含量比WKY大鼠下降[（7．3±2．4）Pg·10^-6比（19．3±3．3）Pg·10^-6，P〈0．01]，AngⅡ含量增加[（57±4）Pg·10^-6比（44±4）Pg·10^-6，P〈0．01]，Na^＋，K^＋-ATP酶、Ca^2＋-ATP酶活性及Na^＋，K^＋-ATP酶α1亚单位、PMCA1mRNA表达均显著降低[Na^＋，K^＋-ATP：（4．3±0．8）μmol·h^-1·mg^-1。比（5．3±1．0）μmol·h^-1·mg^-1，Ca^2＋-ATP酶：（3．2±0．7）μmol·h^-1·mg^-1比（4．5±0．7）μmol·h^-1·mg^-1，α1亚单位：0．524±0．025比0．704±0．116，PMCA1：0．193±0．030比0．547±O．045]（P〈0．05～P〈0．01）。ANP可增加SHR大鼠Na^＋，K^＋-ATP酶、Ca^2＋-ATP酶活性及Na^＋，K^＋-ATP酶α1亚单位及PMCAImRNA表达（均P〈0．01），AngⅡ则抑制Ca^2＋-ATP酶活性和PMCA1mRNA表达（P〈0．05～P〈0．01），仅1×10^-7mol／L AngⅡ抑制Na^＋，K^＋-ATP酶活性及α1亚单位mRNA表达，ANP能拮抗AngⅡ对两种ATP酶活性及其mRNA表达的效应。ANP也能拮抗AngⅡ对WKY大鼠Ca^2＋ATP酶活性及PMCA1mRNA表达的效应，对Na^＋，K^＋-ATP酶活性及α1亚单位mRNA表达无影响（P〉0．05）。结论高血压大鼠ASMC两种ATP酶活性和基因表达下降与局部ANP和AngⅡ分泌异常有关，ANP能拮抗AngⅡ对两种ATP酶活性和基因表达的效应。Objective To explore the effects of atrial natriuretic peptide （ANP） upon the activities of Na^＋, K^＋-ATPase, Ca^2＋-ATPase and mRNA expression levels of Na^＋, K^＋-ATPase α1-subunit and plasma membrane Ca^2＋ -ATPase isoform 1 （PMCA1） in cultured thoracic aortic vascular smooth muscle cells （ASMCs） isolated from spontaneously hypertensive rats （SHR）. Methods ASMCs isolated from 14-week- old male SHR and Wistar-Kyoto （ WKY ） rats were interference-cultured in different doses of ANP and Angiotensin Ⅱ （ Ang Ⅱ ）. The contents of ANP and Ang Ⅱ in supernatant from ASMCs were measured by radioimmunoassay. The activities of the above two ATPases were measured by biochemistry and enzymology. RT-PCR assay was employed to determine the relative levels of Na^＋ , K^ ＋-ATPase α1-subunit and PMCA1 mRNA in ASMCs. Results The ANP level of supernatant in SHR ASMCs was significantly lower than those from WKY control [（7.3±2.4） pg. 10^-6 cells vs （19.3±3.3） pg. 10^-6 cells, P〈0.01] while the content of Ang Ⅱ in SHR ASMCs was significantly higher than those from WKY control [ （57 ±4） pg × 10^-6 ceils vs （44 ±4）pg. 10^ -6 cells, P 〈0. 01 ]. The activity of Na^＋ , K^＋ -ATPase [ （4. 3 ±0. 8） μmol · h^ -1 mg^ - 1 vs （ 5.3 ± 1.0 ） μmol·h ^-1·mg^-1 ] , Ca^2 ＋ -ATPase [ （ 3.2 ± 0. 7 ） μmol·h ^-1·mg^-1 vs （ 4. 5 ± 0. 7 ） μmol·h ^-1·mg^-1] in ASMCs from SHR were significantly lower than those from WKY control （both P 〈 0. 01 ）. The mRNA expression of Na^＋ , K^＋ -ATPase α-subunit （ 0. 524 ±0. 025 vs 0. 704 ± 0. 116 ）, PMCA1 （0. 193 ±0. 030 vs 0. 547± 0. 045 ） significantly decreased in ASMCs from SHR versus the WKY control （ both P 〈 0. 01 ）. As compared with SHR control, exogenous ANP improved obviously the activities of Na^＋, K^＋-ATPase, Ca^2＋ -ATPase and expression of α1-subunit, PMCA1 mRNA in a does-dependent manner （P〈0.05 -P〈0.01）. Exogenous Ang Ⅱ （1 ×10^-9, 1 ×10^-8, 1 ×10^-7m

关 键 词：高血压 心钠素 腺苷三磷酸酶 基因表达 

分 类 号：R686[医药卫生—骨科学]