氯菊酯和氯氰菊酯对大鼠脑突触体Ca~(2+)-和Ca~(2+),Mg~(2+)-ATP酶活性的抑制

氯菊酯可明显抑制Ca~(2+)—ATP酶活性,其抑制作用是可逆的,底物动力学分析表明为非竞争性抑制,介质的酸度可影响其抑制效应;氯氰菊酯对该酶活性无明显影响.氯菊酯和氯氰菊酯均能可逆性地抑制Ca~(2+),Mg~(2+)—ATP酶活性,但氯菊酯为反竞争性抑制.且有一定的pH依赖性,而氯氰菊酯为非竞争性抑制,其抑制率基本不受pH的影响,表明这两种杀虫剂在Ca~(2+) ,Mg~(2+)—ATP酶上有不同的结合位点.     

马桑内酯对大鼠大脑皮层突触膜Ca~(2+)、Mg(2+)-ATP酶作用的量效、时效关系

本文利用大鼠大脑皮层突触膜,研究了致痫剂马桑内酯对膜Ca~(2+)、Mg~(2+)-ATP酶作用的量效、时效关系。结果表明。在6×10~(-9)mol/L-6×10~(-7)mol/L剂量范围内,酶活性明显降低,且与剂量呈明显的负相关(r=-0.992,P<0.01)。随温育时间的延长,同浓度马桑内酯降低酶活性的作用逐渐增强。本文对Ca~(2+)、Mg~(2+)-ATP酶在维持细胞钙稳态中的作用及马桑内酯致痫的可能途径进行了讨论。     

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。     

赛庚啶对离体犬心肌肌质网Ca~(2+),Mg~(2+)—ATP酶活性和~(45)Ca~(2+)摄取功能的影响

当赛庚啶浓度在8×10~(-6)mol/L～2×10~(-4)mol/L之间时,该药对正常犬心肌肌质网Ca~(2+),Mg~(2+)—ATP酶活性几乎没有影响,仅在10~(-3)mol/L时对该酶活性才有一定的抑制作用(抑制率为39.85%,P<0.01)。正常犬心肌肌质网的~(45)Ca~(2+)摄取过程有明显的时间依赖性,至第30 min,其~(45)Ca~(2+)摄取量可达312.79±22.25 nmol/mg protein.赛庚啶对心肌肌质网的~(45)Ca~(2+)摄取有一定的抑制作用,其IC_(50)为1.94×10~(-4)mol/L。     

人参皂苷Rg_1配伍乌头碱对体外培养心衰模型心肌细胞的保护作用

目的:考察人参皂苷Rg_1配伍乌头碱对体外培养心衰模型心肌细胞的保护作用。方法:将新生大鼠心肌细胞分为正常对照组、模型组、阳性对照组(去乙酰毛花苷注射液,1×10~(-7)mol/L)、人参皂苷Rg_1组(1×10~(-8)mol/L)、乌头碱组(1×10~(-9)mol/L)以及人参皂苷Rg_1与乌头碱不同配比的配伍组(1∶1、2∶1、1∶2,V/V)。除正常对照组外,其余各组细胞均以0.8%戊巴比妥钠诱导心肌细胞心衰模型。成模后,各组细胞给予相应药物培养1 h,然后检测细胞总三磷酸腺苷(ATP)酶、Ca~(2+)-Mg~(2+)-ATP酶和Na~+-K~+-ATP酶活力;检测细胞培养液中酸性磷酸酶(ACP)、乳酸脱氢酶(LDH)活力和脑钠肽(BNP)、肿瘤坏死因子α(TNF-α)含量以及细胞中总糖原含量。结果:与正常对照组比较,模型组细胞总ATP酶和Ca~(2+)-Mg~(2+)-ATP酶活力明显降低,Na~+-K~+-ATP酶活力明显升高,培养液中ACP、LDH活力及BNP含量均明显升高(P<0.05)。与模型组比较,各给药组细胞总ATP酶活力显著升高,细胞培养液中LDH活力显著降低,且以人参皂苷Rg1与乌头碱2∶1配伍时作用最强;乌头碱组和各配伍组细胞Na~+-K~+-ATP酶活力均显著降低,差异均有统计学意义(P<0.05);各给药组细胞培养液中ACP、BNP活力均有降低的趋势,细胞内总糖原含量和培养液中TNF-α含量无显著变化(P>0.05)。结论:人参皂苷Rg_1配伍乌头碱可改善大鼠心衰模型心肌细胞ATP酶活力和膜通透性,调节细胞分泌BNP,对心衰模型心肌细胞有一定保护作用,且以人参皂苷Rg_1与乌头碱2∶1配伍时作用最强。     

大鼠氯丙烯中毒对神经纤维微管、神经微丝和胞浆内Ca~(2+),Mg~(2+)含量影响

大鼠sc氯丙烯100和150 mg/kg,研究其对在体神经纤维MT,NF和胞浆内Ca~(2+),Mg~(2+)含量的影响.氯丙烯可引起MT,NF变性和数量减少,胞浆内Ca~(2+)含量升高.Ca~(2+)含量升高能抑制MT聚合和促进其解聚,分解NF蛋白,致使MT和NF减少,抑制或阻断轴浆转运.     

Fura—2荧光测定眼镜蛇心脏毒引起细胞胞浆Ca~(2+)浓度的变化

用Fura—2荧光技术直接测定眼镜蛇心脏毒(CTX)对大鼠泪腺细胞胞浆Ca~(2+)浓度的影响。在无Ca~(2+)的介液下,CTX可使胞浆Ca~(2+)浓度升高;随之加入1mmol/L CaCl_2可使胞浆Ca~(2+)浓度进一步升高。表明CTX能引起胞内Ca~(2+)释放和胞外Ca~(2+)内流。8mmol/L CaCl_2能阻断CTX升高胞浆Ca~(2+)浓度的作用。     

香烟烟雾对大鼠睾丸NO含量及Na~+-K~+-ATP酶、Ca~(2+)-ATP酶活性的影响

目的探讨香烟烟雾对大鼠睾丸组织一氧化氮(NO)含量、Na~+-K~+-ATP酶及Ca~(2+)-ATP酶活性的影响。方法清洁级健康雄性SD大鼠40只,随机分为对照组和低、中、高剂量染毒组(即0、10、20和30支香烟组),每组10只。染毒组大鼠置于自制被动染毒箱中,采用静式染毒方法,1次/d,连续8周。观察大鼠左侧睾丸组织形态结构,测定右侧睾丸组织匀浆中NO含量及Na~+-K~+-ATP酶、Ca~(2+)-ATP酶活性。结果各组大鼠体重增量比较,高剂量染毒组较对照组明显降低,差异有统计学意义(P0.01);与对照组相比,高剂量染毒组大鼠睾丸中NO含量明显升高,Na~+-K~+-ATP酶和Ca~(2+)-ATP酶的活力均明显降低,差异有统计学意义(P0.01);睾丸组织病理学发现,随着染毒剂量的增加,生精小管出现不同程度的退行性改变。结论香烟烟雾可通过改变大鼠睾丸组织中NO含量,降低Na~+-K~+-ATP酶和Ca~(2+)-ATP酶的活力,引起大鼠睾丸损伤。     

白藜芦醇对鼻咽癌细胞ATP酶抑制作用研究

目的检测30μmol/L白藜芦醇对鼻咽癌细胞ATP酶活力及蛋白表达抑制作用。方法超微量ATP酶试剂盒检测白藜芦醇对鼻咽癌细胞膜的Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶和T-ATP酶活力的变化;Western-blot检测白藜芦醇对鼻咽癌细胞ATP酶蛋白表达差异。结果 RES能显著抑制多种鼻咽癌细胞Na+-K+-ATP酶活力(P0.01)、Ca2+-Mg2+-ATP酶活力(P0.01)和T-ATP酶活力(P0.001),Western-blot检测结果显示白藜芦醇能浓度依赖性下调ATP的表达(P0.05)。结论白藜芦醇抑制鼻咽癌细胞株ATP酶活力,显著下调ATP酶蛋白表达,可能是抑制鼻咽癌细胞株增殖的分子机制之一。     

线粒体及内质网对铅引起的[Ca2+]i升高的作用

目的 研究线粒体、内质网Ca^2 -ATP酶以及Na^ 和K^ -ATP酶活力的改变对铅引起的[Ca^2 ]i升高的调节作用，探讨铅引起的[Ca^2 ]i增高对学习记忆功能的影响。方法 Wistar大鼠神经肉瘤C6细胞培养于含醋酸铅的培养液中，于不同时间终止染铅，检测[ca2’]；及线粒体、内质网Ca^2 -ATP酶、Na^ 和K^ -ATP酶活力。结果 (1)0．2μmol／L染铅组：[Ca^2 ]i轻度升高，线粒体Ca^2 -ATP酶、Na^ 和K^ -ATP酶活力升高，内质网酶活力略增高；(2)1．0μmol／L染铅组：[Ca^2 ]；于染铅后0．5h升至最高，以后逐渐降低，波动于iL60～190nmol／L之间；线粒体、内质网Ca^2 -ATP酶、Na^ 和K^ -ATP酶于染铅后0．5h升至最高(分别为未染铅前酶活力的29．1、39．2、10．8和19．8倍)，2d后降至接近正常水平。结论 (1)铅可使Wistar大鼠神经肉瘤C6细胞Ca^2 浓度及线粒体、内质网Ca^2 -ATP酶、Na^ 和K^ -ATP酶活力增高；(2)当[Ca^2 ]i增高不显著时以线粒体Ca^2 -ATP酶、Na^ 和K^ -ATP酶活力增高为主；当[Ca^2 ]i急剧升高时，线粒体、内质网Ca^2 -ATP酶、Na^ 和K^ -ATP酶活力均明显增高，尤其是线粒体Ca^2 -ATP酶、Na^ 和K^ -ATP酶活力增高更为显著。     

人参二醇皂甙和三醇皂甙对兔纹状体ATP酶的影响

本文报道用体外给药法,观察了PDS和PTS对纹状体ATP酶(Na⁺、K⁺-ATP酶,Ca²⁺-ATP酶及M²⁺-ATP酶)的影响。结果发现PDS和PTS对Na⁺,K⁺-ATP酶都有明显的抑制作用,且随PDS和PTS浓度的高低,其抑制作用增强或减弱;对Ca²⁺-ATP酶,PDS在10^-5g/ml时有激活作用,当浓度增高到10^-3g/mL时则转为抑制,而PTS仅为抑制效应;对于Mg²⁺-ATP酶能被PDS所兴奋,而被PTS所抑制。此结果表明PDS和PTS对中枢神经系统的作用,可能与其影响脑内ATP酶有密切的内在联系。     

Effects of calcium antagonists on (Na+ + K+)-ATPase, Mg2+-ATPase and Ca2+-ATPase activities of rat cortical synaptosomes

1. The effects of 11 calcium antagonists on (Na+ + K+)-ATPase, Mg2+-ATPase and Ca2+-ATPase activities of rat cortical synaptosomes were studied. 2. All the calcium antagonists studied had inhibitory effects on ouabain-sensitive (Na+ + K+)-ATPase, Mg2+-ATPase and Ca2+-ATPase activities in synaptosomes at high concentrations (10 or 100 microM). 3. Calcium antagonists such as trifluoperazine, flunarizine and cinnarizine had inhibitory effects on Ca2+-ATPase activity at low concentrations (1-10 microM). 4. Trifluoperazine and La3+ had inhibitory effects on Mg2+-ATPase activity at low concentration (1 microM). 5. Our results suggest that most of the calcium antagonists studied have little effects on neuronal (Na+ + K+)-ATPase, Mg2+-ATPase and Ca2+-ATPase activities at therapeutic dose ranges (1 microM or lower).     

Calmodulin-stimulated plasma membrane (Ca2+ + Mg2+)-ATPase: inhibition by calcium channel entry blockers

Calcium channel entry blockers representing different structural classes were studied for their effects on human erythrocyte basal and calmodulin-stimulated (Ca2+ + Mg2+)-ATPase. Effects on the activity of (Mg2+)-ATPase and (Na+ + K+)-ATPase were also assessed. Of the four Ca2+ entry blockers tested, only verapamil and diltiazem specifically inhibited the calmodulin-stimulated (Ca2+ + Mg2+)-ATPase activity, the basal enzyme activity being unaltered by these drugs. Other membrane-associated ATPases were not affected. Calmodulin concentration effect curves showed the inhibition by verapamil (10(-3) M) and diltiazem (10(-3) M) to be non-competitive. This concentration inhibited the calmodulin-dependent increment (5.1 nM calmodulin) of the ATPase activity by 35 and 36% respectively. Similarly, both drugs inhibited the Ca2+-activation process of calmodulin-stimulated activity in a non-competitive manner, decreasing Vmax by 23 and 17% respectively. Basal (Ca2+ + Mg2+)-ATPase activity was not affected by verapamil or diltiazem at any calcium concentration. In contrast, cinnarizine non-specifically inhibited all four membrane ATPases including calmodulin-stimulated (Ca2+ + Mg2+)-ATPase activity at concentrations above 3 X 10(-6) M. Nifedipine was without effect on any of the four membrane ATPases. From this we conclude that certain calcium channel entry blockers can inhibit calmodulin-regulated plasma membrane Ca2+-pump ATPase. Therefore, this identifies an additional functional low affinity receptor in the plasma membrane for some of the calcium channel entry blockers.     

亚慢性铅接触大鼠体内钙调素和腺嘌呤核苷三磷酸酶的影响

大鼠以1.318、5.272和10.545mmol醋酸铅染毒3个月。各染毒组大鼠全血中钙调素(CaM)含量和红细胞膜钙-腺嘌呤核苷三磷酸酶(Ca~(2+)-ATPase)活力显著下降,呈剂量-效应关系。高剂量组红细胞钠-钾-腺嘌呤核苷三磷酸酶(Na~+-K~+-ATPase)活力明显抑制。电镜细胞化学观察,肝细胞腺嘌呤核苷三磷酸酶电子密度变浅、分布减少。     

SiO_2粉尘对巨噬细胞膜Mg~(2+)-ATP酶活性影响的时相研究——电镜酶细胞化学观察

本研究结果表明,SiO_2粉尘早期对细胞膜的损伤及其引起的膜通透性的改变可能是造成巨噬细胞不可逆损伤乃至死亡的主要原因。     

INTERACTION OF THE NON-STEROIDAL ANTIINFLAMMATORY DRUG FLUFENAMIC ACID WITH GASTRIC ACID SECRETION AND H+/K+ -ATPase

1. The effects of the non-steroidal anti-inflammatory drug (NSAID) flufenamic acid on H+ production in isolated and enriched guinea-pig parietal cells and on H+/K(+)-ATPase activity in ion-tight inside-out membrane vesicles from pig gastric mucosa were studied. 2. At low concentrations (0.1 and 1.0 mumol/L), flufenamic acid increased the secretory response of parietal cells to dibutyryl cyclic AMP (dbcAMP). At higher concentrations (10 and 100 mumol/L) it progressively inhibited basal and dbcAMP-stimulated acid production. 3. Flufenamic acid (10 mumol/L) increased K+ (0.5-10.0 mmol/L) and K+ (0.5-1.0 mmol/L) plus gramicidin-stimulated ATPase activity in gastric membrane vesicles. The Km value for K+ (1.6 and 1.0 mmol/L in the absence and presence of gramicidin, respectively) was decreased to 0.8 and 0.5 mmol/L, respectively. At higher concentrations (greater than or equal to 50 mumol/L), flufenamic acid inhibited K+ plus gramicidin-stimulated ATPase activity (inhibited concentration at 50% [IC50] = 186 mumol/L) and reduced the proton concentration (IC50 = 50 mumol/L). 4. It is concluded that flufenamic acid-induced enhancement of dibutyryl cyclic AMP-stimulated H+ production in the parietal cell reflects the stimulation of H+/K(+)-ATPase. We suggest that activation of the enzyme involves increased affinity of K+ towards the K(+)-binding site of the enzyme and/or increased KCl permeability at the vesicle membrane. The inhibitory action of the drug on H+ production in parietal cells results from a detergent and/or protonophoric-like action at the apical parietal cell membrane, and from inhibition of H+/K(+)-ATPase activity.     

17Beta-oestradiol regulates the expression of Na+/K+-ATPase beta1-subunit, sarcoplasmic reticulum Ca2+-ATPase and carbonic anhydrase iv in H9C2 cells

1. It is necessary to improve our understanding of the effect of 17beta-oestradiol (E2) on the heart at a molecular and cellular level. In the present study, the effects of E2 on Na(+)/K(+)-ATPase, sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA) and carbonic anhydrase IV (CAIV) in H9C2 cells were investigated. To identify the mechanism of action of E2 on these proteins, the oestrogen receptor (ER) antagonist tamoxifen was used. 2. The results indicated that 1 and 100 nmol/L E2 can enhance the activity of Na(+)/K(+)-ATPase and SERCA and upregulate the expression of the Na(+)/K(+)-ATPase beta1-subunit, SERCA2a and CAIV at both the mRNA and protein level compared with 0 and 0.01 nmol/L E2. 17beta-Oestradiol had the greatest effect at 100 nmol/L; 1 micromol/L E2 did not further protein expression compared with 100 nmol/L E2. 3. Tamoxifen (10 nmol/L) significantly decreased the activity of SERCA, as well as the expression of the Na(+)/K(+)-ATPase beta1-subunit and SERCA at the mRNA and protein level, in H9C2 cells cultured with 1 nmol/L E2. Tamoxifen alone had no significant effect on these proteins in H9C2 cells. 4. It may be hypothesized that a suitable E2 concentration has a protective effect on the heart and that the actual dose of E2 used in hormone-replacement therapy is important in menopausal women.     

In vivo and in vitro effects of cadmium on adult rat brain total antioxidant status, acetylcholinesterase, (Na+, K+)-ATPase and Mg2+-ATPase activities: protection by L-cysteine

This study was undertaken in order to investigate a) the short- and long-term in vivo effects of cadmium (Cd) on brain acetylcholinesterase (AChE), (Na+, K+)-ATPase activities in adult rats, b) the concentration-dependent in vitro and in vivo (acute experiment) effects of Cd on the activity of those enzymes, c) the in vivo and in vitro effects of the antioxidant L-cysteine (Cys) on the above enzyme activities, and d) the evaluation of brain total antioxidant status after in vivo Cd, L-cysteine, or L-cysteine+Cd administration in rats. In vitro, CdSO4 inhibited pure and brain AChE in concentrations higher than 0.1 mM, while it activated by approximately 70% (P<0.001) brain Na+, K+ -ATPase in concentrations up to 0.1 mM and inhibited its activity in higher concentrations. Mg2+ -ATPase was not influenced up to 0.1 mM concentration, while it was inactivated (40%, P<0.001) in higher CdSO4 concentrations. A dose-response study of brain CdSO4 (1,2 and 5 mg/kg once 8 hr before decapitation) revealed a dose-dependent decrease (-14 to -30%, P<0.001) of brain AChE activity, an increase of Na+, K+ -ATPase activity (+47 to +200%, P<0.001) and an increase of Mg2+ -ATPase only after the highest dose (5mg/kg) in the short-term treatment of rats. Long-term Cd administration (1 mg/kg rat daily for 4 months) activated brain AChE and Na+, K+ -ATPase about 50-65% (P<0.001) but not Mg2+ -ATPase. Brain total antioxidant status was decreased by Cd (30%, P<0.01), while it was increased by L-cysteine or L-cysteine+Cd (50%, P<0.001) in the short-term in vivo treatment. L-cysteine reversed the enzymatic activity changes observed with Cd alone in the high-dose short-term in vivo treatment of rats, as well as the brain AChE inhibition induced by Cd in the in vitro experiments. These results indicate that: a) Cd can influence in a different way the examined enzyme activities after short- and long-term administration, b) Cd may modulate brain cholinergic mechanism(s), neural excitability and metabolic energy production, and c) L-cysteine can have a protective antioxidant effect on the oxidative stress of the brain induced by Cd.