性激素对豚鼠心肌细胞膜Na~+,K~+-ATP酶活力的影响

采用Matsui and Schwartz方法制备Na~+,K~+—ATP酶液,Harry法测定无机磷含量,间接测定心肌细胞膜Na~+,K~+—ATP酶活力,实验结果表明,丙酸睾丸素、已烯雌酚对心肌细胞膜Na~+,K~+—ATP酶活性均有明显的抑制作用。但丙酸睾丸素呈正相关,已烯雌酚呈负相关,说明性腺激素可以使心肌细胞膜上的Na~+,K~+—ATP酶活性降低。     

人参皂甙对犬心肌Na~+、K~+-ATP酶活力的影响

人参茎叶总皂甙(GNS)和人参根总皂甙(GRS)10、20和40mg/kg,显著抑制犬心肌细胞膜Na~+,K~+-ATP酶的活力;人参茎叶二醇组皂甙(PDS)和三醇组皂甙(PTS)5、10和20mg/kg,也显著抑制Na~+,K~+-ATP酶的活力。离体实验表明:GNS、GRS、PDS和PTS在0.01、0.10和1.00g/L,对犬心肌细胞膜Na~+,K~+-ATP酶的活力均具有抑制作用。提示人参的正性肌力作用可能与其对心肌Na~+,K~+-ATP酶的抑制有关。     

氯胺酮对脑缺血大鼠纹状体DA含量和Na~+,K~+-ATP酶活性的影响

目的研究脑缺血大鼠纹状体多巴胺含量和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的变化以及ＮＭＤＡ受体拮抗剂氯胺酮对这些变化的影响。方法采用大鼠４－Ｖ－Ｏ造成急性脑缺血模型，缺血１０ｍｉｎ后分别应用ＨＰＬＣ－ＥＣＤ和比色法测量纹状体ＤＡ含量以及Ｎａ＋，Ｋ＋－ＡＴＰ酶活性。结果脑缺血前１５ｍｉｎ腹腔注射氯胺酮（２５ｍｇｋｇ－１和５０ｍｇｋｇ－１）能明显拮抗脑缺血时ＤＡ含量和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的降低。结论氯胺酮可通过阻断ＮＭＤＡ受体，抑制纹状体ＤＡ释放和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的降低，对抗脑缺血损伤。     

Na~+,K~+-ATP酶不参与慢性心衰豚鼠心肌细胞钙瞬变的减小

目的研究Na+,K+-ATP酶是否参与慢性心衰(CHF)豚鼠心肌细胞钙瞬变的减小。方法采用降主动脉缩窄(CDA)法和异丙肾(ISO)法建立豚鼠慢性心衰模型;酶解法急性分离左室心肌细胞;采用无机磷法测定心肌细胞膜Na+,K+-ATP酶活性,采用RT-PCR和Western blot检测CHF心肌Na+,K+-ATP酶α1、α2亚单位在mRNA水平和蛋白水平的表达。结果CDA法致心衰后Na+,K+-ATPα1、α2亚单位在mRNA水平均明显减少,ISO法α1明显减少,α2无变化;但两种方法致豚鼠CHF后,心肌细胞Na+,K+-ATP酶α1亚单位在蛋白水平的表达及酶活性均无改变。结论豚鼠CHF后钙瞬变的减小,没有Na+,K+-ATP酶的参与。     

孕酮对卵母细胞膜K~+、Na~+通透性的影响

本文采用微电极细胞内记录方法观察了孕酮对卵母细胞膜K~+、Na~+通透性的影响,其中重点观察了高钾溶液和低钠溶液对膜Na~+通透性的影响。结果提示孕酮处理后卵母细胞K~+、Na~+通透性皆降低,~TK~+(K~-转运系数)降低程度与膜静息电位水平呈高度正相关。     

类固醇性激素对豚鼠心室肌细胞膜Na~+,K~+—ATPase活力影响

采用 Harry 法测定无机磷含量,间接测定心肌细胞膜 Na~+,K~+—ATPase 酶活力,结果表明,性激素对心肌细胞膜 Na~+,K~+—ATPase 活力均有抑制作用。说明性激素可以使心肌细胞膜上的 Na~+,K~+—ATPAase 活力下降。     

中药大黄的生化学研究ⅩⅫ蒽醌衍生物对兔肾髓质Na~+-K~+-ATP酶活性的抑制和利尿作用

家兔实验表明:大黄素、大黄酸以30 mg/kg的剂量灌胃给药,2～4h后尿量、排Na~+和K~+量达最高峰,比对照组明显增多。而芦荟大黄素和大黄酚的作用较弱。大黄素、大黄酸和芦荟大黄素对免肾髓质Na~+-K~+-ATP酶活性有较强的竞争性抑制作用。     

大鼠缺血性全脑损伤Na~+,K~+-ATP酶活性及其α亚基表达的变化

目的研究大鼠全脑缺血后,脑组织Na+,K+-ATPase活性及其α亚基的变化。方法采用大鼠双侧颈总动脉结扎全脑缺血模型,测定缺血后脑组织H2O,Na+和K+含量及Na+,K+-ATPase的活性,采用免疫组织化学的方法观察Na+,K+-ATPaseα亚基的改变。结果全脑缺血后,脑组织的H2O和Na+的含量明显增加,K+含量及Na+,K+-AT-Pase活性明显降低,正常大鼠海马和皮层神经元上主要分布α1和α3亚基,而α2表达较少,脑缺血后,α1和α3亚基的表达明显减少。结论Na+,K+-ATPaseα1和α3亚基参与了缺血性脑损伤。     

熟地黄水提液对小鼠红细胞膜Na~+、K~+-ATPase活性及MDA含量的影响

本实验研究采用D-半乳糖衰老模型小鼠,灌胃熟地黄水提液30d,测定脑Na+、K+－ATPase活性和MDA含量．结果表明,与衰老模型组比较,熟地黄水提液能显著提高小鼠红细胞膜Na+、K+－ATPase活性,显著降低MDA含量（P<0．01）．     

参麦注射液静注对红细胞膜Na~ -K~ -ATP酶的影响

为了解参脉注射液对患者红细胞(RBC)膜Na~ -K~ -ATP酶的影响,本研究随机选择级择期上腹部手术男性患者60例,根据参脉给药剂量的不同,随机分为三组,每组20例:Ⅰ组、Ⅱ组和Ⅲ组剂量分别为40,60,80 mg/kg。给药后10,20,30min时测定各组患者静脉血红细胞膜Na~ -K~ -ATP酶活性,各组患者血压、心率、氧饱和度的变化也同时被记录。结果发现:参脉注射液对RBC膜Na~ -K~ -ATP酶活性具有短暂的抑制作用,当参脉注射液输液量为80 mg/kg时对心率也存在短暂的减慢作用。     

白术水煎剂对老龄大鼠心肌Na~+,K~+-ATPase和血清TAA的影响

目的：探讨白术对老年大鼠心肌细胞膜钠钾ＡＴＰ酶（Ｎａ＋,Ｋ＋－ＡＴＰａｓｅ）活性和总抗氧化能力（ＴＡＡ）的影响,及产生显著影响的时间．方法：给老年Ｗｉｓｔａｒ大鼠灌服白术水煎制,制备血清、心肌匀浆和心肌细胞膜,分别测定血清ＴＡＡ和Ｎａ＋, Ｋ＋－ＡＴＰａｓｅ活性,并与对照组进行比较．结果：老年大鼠心肌 Ｎａ＋, Ｋ＋－ＡＴＰａｓｅ活性和ＴＡＡ明显低于青年对照组（Ｐ＜０．０５, Ｐ＜０．０１）．灌服白术后３０天心肌Ｎａ＋, Ｋ＋－ＡＴＰａｓｅ明显高于老年时照组,分别为（０． ９１± ０． ０５）、（０． ６２ ± ０． ０９）μ　ｍｏｌＰｉ．ｍｇ－１Ｐｒ．ｈ－１;而血清ＴＡＡ在２０天时明显高于老年对照组,分别为（６．６６±０．９０）、（５．３８±０．５８）Ｕ．ｍｌ－１;两组各项比较差异均有显著性（Ｐ＜０．０１）;血清ＴＡＡ和Ｎａ＋,Ｋ＋－ＡＴＰａｓｅ呈显著的正相关。结论：白术能明显增强心肌Ｎａ＋,Ｋ＋－ＡＴＰａｓｅ活性,其机理可能与血清ＴＡＡ的提高有关,白术的显效时间为 ３０天．     

Effect of methyl isocyanate on rabbit cardiac Na+, K+-ATPase

 The present study describes the effect of methyl isocyanate (MIC) on rabbit cardiac microsomal Na⁺, K⁺-ATPase. Addition of MIC in vitro resulted in dose-dependent inhibition of Na⁺, K⁺-ATPase, Mg²⁺-ATPase and K⁺-activated p-nitrophenyl phosphatase (K⁺-PNPPase). Activation of Na⁺, K⁺- ATPase by ATP in the presence of MIC showed a decrease in V_max with no change in K_m. Similarly, activation of K⁺ PNPPase by PNPP in the presence of MIC showed a decrease in V_max with no change in K_m. The circular dichroism spectral studies revealed that MIC interaction with Na⁺, K⁺-ATPase led to a conformation of the protein wherein the substrates Na⁺ and K⁺ were no longer able to bind at the Na⁺- and K⁺-activation sites. The data suggest that the inhibition of Na⁺, K⁺-ATPase was non-competitive and occurred by interference with the dephosphorylation of the enzyme-phosphoryl complex. Received: 3 November 1994/Accepted: 23 February 1995     

白术、附子、肉桂合剂对老龄大鼠心肌Na^＋,K^＋—ATPase和血清TAA的影响

目的:探讨白术、附子、肉桂合剂对老年大鼠心肌细胞膜钠钾ATP酶(Na,K-ATPase)活性和总抗氧化能力(TAA)的影响,及产生显著影响的时间。方法:给老年Wistar大鼠灌服白术、附子、肉桂合剂水煎剂,制备血清、心肌匀浆和心肌细胞膜,分别测定血清TAA和Na+,K+-ATPase活性,并与对照组进行比较。结果:老年大鼠心肌Na+,K+-ATPase活性和TAA明显低于青年对照组(P<0.05,P<0.01)。灌服合剂后30天心肌Na+,K+-ATPase明显高于老年对照组,分别为(0.910.05)、(0.620.09)μmolPimg-1Prh-1 ;而血清TAA在20天时明显高于老年对照组,分别为(8.451.78)、(5.380.58)Uml-1;两组各项比较差异均有显著性(P<0.01);血清TAA和Na+,K+-ATPase呈显著的正相关。结论:合剂能明显增强心肌Na+,K+-ATPase活性,其机理可能与血清TAA的提高有关,其显效时间为30天。     

几种人参皂甙对大鼠肾脏微粒体Na~+,K~+-ATP酶的抑制作用

人参皂甙Rg组、Rb组、Rg_1、Rb_1对大鼠肾脏微粒体Na~+,K~+—ATP酶均有抑制作用,IC_(50)分别为402,74μg/ml,15和50μmol/L。Rb组、Rg_1和Rb_1的抑酶作用可逆;增加K~+可竞争性拮抗Rg_1和Rb_1的抑酶作用,但Na~+对此作用无明显影响。动力学研究表明,Rg_1和Rb_1抑制Na~+,K~+—ATP酶,对底物ATP似为反竞争性抑制剂。     

异丙酚、氯胺酮对大鼠突触体Na~ ,K~ -ATP酶活性的影响

目的观察异丙酚、氯胺酮对大鼠不同脑区突触体Na ,K -ATP酶活性的影响。方法SD大鼠 ,随机分为三组 ,每组10只 ,分别ip生理盐水10ml/kg(对照组) ,异丙酚100mg/kg 或氯胺酮100mg/kg。用分光光度法测定大脑皮层、海马和脑干突触体Na ,K -ATP酶活性。结果与对照组比较 ,异丙酚明显抑制大脑皮层、海马和脑干突触体Na ,K -ATP酶活性(P<0.01),氯胺酮明显降低大脑皮层和脑干突触体Na ,K -ATP酶活性(P<0.01) ,但对海马突触体Na ,K -ATP酶活性无明显影响(P<0.01)。结论异丙酚、氯胺酮的全身麻醉作用可能与其抑制脑突触体Na ,K -ATP酶活性有关     

哇巴因抑制钠泵β1亚单位和VE-cadherin减弱血管内皮细胞连接功能

目的探讨钠泵抑制剂哇巴因对血管内皮细胞连接的影响及机制。方法以人脐静脉内皮细胞(HUVECs)为靶细胞,Hoechst33342/PI双荧光染色法观察哇巴因作用后细胞凋亡或坏死特征,透射电镜和光镜观察细胞形态结构变化。应用半定量聚合酶链反应检测钠泵α1亚单位、β1亚单位、VE-cadherin和SnailmRNA的表达。结果0.1μmol.L-1哇巴因作用HUVECs24～48h,细胞死亡以凋亡为主,10μmol·L-1哇巴因作用24h,引起细胞坏死;对照组细胞间的细胞连接数量多,结构清晰,而经哇巴因作用后,细胞连接丧失,细胞脱落。哇巴因作用HUVECs后,钠泵α1亚单位和Snail表达上调,β1亚单位和VE-cadherin表达下降,其改变均呈剂量和时间依赖性。结论哇巴因通过下调血管内皮细胞钠泵β1亚单位和VE-cadherin的表达使细胞连接功能减弱。     

Interaction between theophylline and ouabain in the rabbit heart: Effect on (Na + K)-ATPase

In electrically stimulated rabbit ventricular strips, theophylline (0.3–30 M) antagonized the increased contractility produced by ouabain (0.8 μM). Initial velocity of specific [³H]ouabain binding to homogenates prepared from the muscle strips was used to determine the fraction of binding sites occupied by ouabain. Theophylline decreased the binding of ouabain to (Na⁺ + K⁺)-ATPase. It is concluded that the effect of theophylline on ouabain-induced positive inotropism may be mediated by decreased ouabain binding to (Na⁺ + K⁺)-ATPase.     

氯胺酮对大鼠大脑皮质、脑干、纹状体和海马Na~＋，K~＋－ATP酶活性的影响

大鼠ｉｐ不同剂量的氯胺酮（５０，１００，２００ｍｇ·ｋｇ－１），除小剂量（５０ｍｇ·ｋｇ－１）兴奋大脑皮质Ｎａ＋．Ｋ＋－ＡＴＰ酶活性外，其余剂量对鼠脑４个分区的酶活性均有抑制作用．５０ｍｇ·ｋｇ－１氯胺酮显著抑制海马Ｎａ＋，Ｋ＋－ＡＴＰ酶，１００ｍｇ·ｋｇ－１显著抑制大脑皮质、纹状体和海马Ｎａ＋，Ｋ＋－ＡＴＰ酶；２００ｍｇ·ｋｇ－１显著抑制脑干和海马Ｎａ＋，Ｋ＋－ＡＴＰ酶。结果提示．氯胺酮对中枢神经系统的抑制作用可能与其抑制脑组织中Ｎａ＋，Ｋ＋－ＡＴＰ酶活性有关。     

Insights into the mechanism of erythrocyte Na+/K+-ATPase inhibition by nitric oxide and peroxynitrite anion

Evidence shows that Na(+)/K(+)-ATPase from kidney, brain and liver is inhibited by nitric oxide (NO) and peroxynitrite anion (ONO(2) (-)), but the mechanism is unknown. The aim of the present work was to study the inhibitory effect of NO and ONO(2) (-) on erythrocyte Na(+)/K(+)-ATPase. Erythrocyte membranes were isolated from male Wistar rats by hypotonic washing. The membranes (free from haemoglobin) were incubated for Na(+)/K(+)-ATPase activity measurement at various concentrations of ATP in the presence or absence of 400 microM SNAP (an NO donor) or 100 microM SIN-1 (an ONO(2)(-) donor). At these concentrations, SNAP and SIN-1 released about the same amount (100 microM) of NO or ONO(2)(-), respectively, as monitored by measuring NO(2)(-) + NO(3)(-). Both SNAP and SIN-1 decreased V(max) by ca. 75% but they did not decrease the apparent affinity of the Na(+)/K(+)-ATPase for the substrate (a decrease of K(m) was even observed after SNAP treatment). The pattern of this inhibition is compatible either with oxidation of SH groups directly involved in ATP binding but in a way that is not surmountable by increasing the substrate concentration ("non-competitive") or with oxidation of SH groups located outside the active site of the enzyme but important for the activity of the enzyme.