美西律对大鼠背根神经节细胞钠电流的抑制作用

应用膜片钳技术,全细胞钳位方式可见Mex对大鼠背根神经节细胞Na~ 电流有明显的抑制作用。其临界作用浓度为5 μmol·L~(-1),50％抑制浓度为31 μmol·L~(-1),完全抑制浓度为150 μmol·L~(-1)。其抑制作用具有电压和频率依赖性。抑制剂量与小鼠抗脑缺血缺氧作用量相近。提示Mex抗脑缺血缺氧作用的机制之一可能是通过对Na~ 电流的抑制。     

蜂毒肽对豚鼠心肌线粒体Na~ 、K~ -ATP酶的影响(英文)

目的:研究蜂毒肽对豚鼠心肌线粒体Na~ ,K~ -ATP酶活性的影响。方法:应用光电比色法测定Na~ ,K~ -ATP酶活性。以Line-weaver-burk双倒数作图法分析酶动力学参数。结果:蜂毒肽抑制心肌Na~ ,K~ -ATP酶表现为浓度和时间依赖性,IC_(50)为2.60μmol/L。酶动力学研究表明,蜂毒肽对Na~ ,K~ -ATP酶有抑制作用,对K~ 表现为竞争性结合,对Na~ 及ATP表现为非竞争性结合。结论:蜂毒肽对心肌Na~ ,K~ -ATP酶有抑制作用,其抑制机制主要是与K~ 竞争结合酶外侧的K~ 结合位点。     

导电聚合物膜修饰电极用于对乙酰氨基酚和抗坏血酸的同时测定

目的:研究对乙酰氨基酚和抗坏血酸在4-(2-吡啶偶氮)间苯二酚(PAR)导电聚合膜修饰电极上的电化学行为,建立同时测定对乙酰氮基酚和抗坏血酸含量的电化学分析新方法。方法:采用循环伏安法研究对乙酰氨基酚和抗坏血酸在膜修饰电极上的电化学行为,以差示脉冲伏安对二者含量进行测定。结果:聚 PAR 膜修饰电极对对乙酰氨基酚和抗坏血酸有很强电催化作用,明显增强了电极反应的可逆性。在 pH 6.0磷酸盐缓冲液中,对乙酰氨基酚氧化峰电流与其浓度在1.0×10~(-8)～1.5×10~(-5),5×10~(-5)～4×10~(-4)mol·L~(-1)范围内呈良好的线性关系,抗坏血酸氧化峰电流与其浓度在1.0×10~(-6)～3.0×10~(-4)mol·L~(-1)范围内呈良好的线性关系,检出限分别为5.0×10~(-9)mol·L~(-1)和5.0×10~(-7)mol·L~(-1)。结论:该修饰电极可以对对乙酰氨基酚和抗坏血酸进行单独或同时的测定,并用于实际样品维 C 银翘片中对乙酰氨基酚和抗坏血酸的含量检测,结果令人满意。     

六种强心甙对羊心脏浦肯野纤维钠泵活动的抑制作用

用离子选择微电极定量研究了数种强心甙对羊心脏浦肯野纤维膜钠泵活动的抑制作用,表明从30 nmol·L~(-1)开始a~1Na有较明显的升高,较高浓度(0.4μmol·L~(-1))时a~1Na进一步升高,后除极(DAD)出现时钠泵活动抑制的百分比在不同药物较接近,其范围在52.8％—65.5％。经计算,由于钠泵受抑制细胞摄取Na~ 引起的内向电流能引起异常自律活动。     

血小板活化因子诱导血小板P-选择素表达及相关信号传导机制(英文)

目的:研究PAF诱导P-选择素表达的细胞内信号机制。方法:置备人血小板悬液,用流式细胞术测定PAF诱导的P-选择素表达。结果:用依他酸2mmol·L~(-1)和BAPTA200μmol·L~(-1)分别阻断外钙内流和络合内钙,显著抑制PAF诱导的P-选择素表达[13.3±0.9)％;(16.8±1.9)％ vs PAF对照组(47.5±1.3)％,P<0.01]。用阿米洛利400μmol·L~(-1)抑制Na~ /H~ 交换,Genistein 300μmol·L~(-1)抑制蛋白酪氨酸磷酸化也均可抑制PAF引起的P-选择素上调[(37.5±2.1)％;(29±4)％ vsPAF对照组(47.5±1.3)％,P<0.01)]。结论:蛋白酪氨酸磷酸化,细胞内钙动员及Na~ /H~ 交换激活中介PAF诱导的血小板P-选择素表达。     

巴氯芬对大鼠背根神经节神经元NMDA激活电流的抑制作用(英文)

目的:探索巴氯芬对大鼠初级感觉神经元膜NMDA激活电流的调制作用。方法:全细胞膜片箝技术在新鲜分离的背根神经节(DRG)细胞上进行实验。结果:DRG细胞外加巴氯芬(1-100μmol·L~(-1))未记录到可检测的膜电流改变,但预加巴氯芬对NMDA激活电流则有明显的抑制作用,巴氯芬100μmol·L~(-1)对NMDA(100 μmol·L~(-1))激活电流的抑制可达52％±14％(n=11,P<0.01),此抑制作用被GABA_B受体的拮抗剂沙氯芬(100 μmol·L~(-1))所取消,结论:初级感觉神经元膜上GABA_B受体的激活对NMDA受体介导的膜电流具有抑制作用。     

去甲肾上腺素对家兔心肌钠——钾——三磷酸腺苷酶活性和环——一磷酸腺苷水平的影响以及胰岛素的拮抗效应

心室纤颤是急性心肌梗塞病人猝死的主要原因之一,由于心肌梗塞急性期容易发生心室纤颤的真正原因至今尚未阐明,因而有效的防治药物仍在探索之中。过去的研究工作基本上确定了心律失常与梗塞的心肌细胞失钾有关,并且证明缺血心肌细胞质膜钠-钾-三磷酸腺苷酶(Na~+-K~+-ATP酶)活性减低。可是,导致Na~+-K~+-ATP酶活性减低的原因仍未阐明。Opie提出与梗塞心肌ATP生成减低、供给Na~+-K~+-ATP酶能量减少有关;Kurien等提出与梗塞心肌细胞内游离脂肪     

中国人肝微粒体细胞色素P450 2A6的体外代谢特征

目的:观察人肝微粒体CYP2A6动力学特征.方法:采用生化分析法,体外研究化学异物对CYP2A6酶活性的影响.测定香豆素7-羟化酶的动力学参数.同时分析CYP2A6与Ⅱ相酶UGT之间的相关性.结果:CYP2A6活性差异8.8倍,K_m和V_(max)分别为0.25-1.56μmol·L~(-1)、1.41-8.70μmol·min~(-1)·g~(-1).匹鲁卡品、二乙基二硫代氨基甲酸盐、利福平明显抑制CYP2A6活性,IC_(50)值分别为 5.31μmol·L~(-1)、156.35μmol·L~(-1)和38.81μmol·L~(-1).α-萘黄酮、磺胺苯吡唑、醋竹桃霉素、酮康唑、泼尼松龙和阿奇霉素对香豆素7-羟化反应几乎无影响.CYP2A6与UGT_2之间存在显著相关性(r=0.9453,P<0.05).结论:中国人细胞色素P4502A6酶活性及动力学参数存在个体差异,CYP2A6与UGT_2之间有显著相关.除匹鲁卡品有CYP2A6选择性抑制作用外,利福平和二乙基二硫代氨基甲酸盐也明显抑制CYP2A6活性.     

戈那瑞林对大鼠脊神经节细胞GABA引起的去极化及GABA激活电流的调制作用(英文)

目的:探索戈那瑞林对大鼠初级感觉神经元膜GABA引起的去极化和GABA激活电流的调制作用。方法:应用细胞内记录和全细胞膜片钳技术分别在大鼠脊神经节(SG)标本和新鲜分离神经元进行实验。结果:GABA(10 μmol·L~(-1)—1mmol·L~(-1))在大多数神经元引起可为荷包牡丹碱(100μmol·L~(-1))所阻断的膜去极化。预加戈那瑞林(50μmol·L~(-1))可减少GABA引起的去极化,抑制率为79±22％(n=29),而戈那瑞林本身不产生膜反应或只引起轻微去极化。在11个细胞中有6个细胞GABA激活电流也为戈那瑞林的预处理所抑制,另5个细胞无改变或反应稍有增加。结论:戈那瑞林对初级感觉神经元GABA介导的去极化和GABA激活电流具有抑制作用。     

2-(2-取代苯基)噻唑-4-(甲)乙酸类化合物的设计、合成及抗肿瘤活性

目的为了寻找有效的Pin1小分子抑制剂,以2-苯基咪唑-4-甲酸为先导化合物,设计并合成了18个2-(2-取代苯基)噻唑-4-(甲)乙酸类化合物8a-8r。方法以2-甲氧基苯甲酸为起始原料,经8步反应得到目标化合物;利用已建立的酶活性筛选平台测试了目标化合物浓度为10μmol·L~(-1)时对Pin1酶的抑制率;采用MTT法,考察了目标化合物对人前列腺癌PC-3细胞的生长抑制作用。结果与讨论合成了18个未见文献报道的化合物,其结构经~1H-NMR谱和MS谱确证;多数化合物具有Pin1抑制活性,其中化合物8 h的抑制率达到100%;化合物的整体细胞生长抑制作用较弱,化合物8 c和8 g对PC-3细胞具有中等生长抑制作用。     

(Na+ -K+)ATPase activity in erythrocyte membranes of spontaneously, one kidney-one wrapped, and deoxycorticosterone acetate--NaCl hypertensive rats

(Na+ -K+)ATPase activity in erythrocyte membranes of spontaneously (SHR), one kidney-one wrapped, and deoxycorticosterone acetate (DOCA)-NaCl hypertensive rats was studied. (Na+ -K+) ATPase activity decreased in both prehypertensive (6 weeks old) and hypertensive (14 weeks old) stages of SHR, suggesting that the alteration of this enzymic activity may be due to a pre-existing defect in the membrane rather than being a consequence of hypertension. By contrast, (Na+ -K+)ATPase activity remained unchanged in the one kidney-one wrapped hypertensive rats, whereas that of one kidney-one wrapped normotensive rats as well as that of DOCA-NaCl hypertensive rats was increased significantly (P less than 0.05). These changes were specific for (Na+ -K+) ATPase, since Mg2+-ATPase activity was not altered. The susceptibility of (Na+ -K+)ATPase to the inhibitory action of ouabain was not changed significantly. These findings indicate that (Na+ -K+)ATPase activities of erythrocyte membranes isolated from the different types of hypertensive rats were subject to different changes. Whether this phenomenon applies to the clinical distinctions among the various types of hypertension remains a subject for further investigation.     

Sex differences in erythrocyte membrane ATPase activities evidenced by exposing the cells to different hemolytic solutions

Erythrocytes from twenty-five normal subjects were hemolyzed in both 20 mM imidazole and in ice-cold deionized water to determine their effects on membrane enzyme activities and protein concentration. Erythrocyte (Ca++)ATPase activity and membrane protein concentration were significantly different (p less than 0.01) following different hemolyses, whereas (Na+-K)ATPase and (Mg++)ATPase activities were not significantly affected. In order to test the influence of sex, erythrocyte protein concentration and enzyme activities were studied separately in male and female groups after each hemolytic solution. After hemolysis in water, females showed a significant increase in erythrocyte protein concentration (p less than 0.01) and in (Mg++)ATPase activity (p less than 0.005), whereas males showed a significant decrease in (Ca++)ATPase activity (p less than 0.02). The most reproducible results were obtained in the male group and after hemolysis in water. Females showed a significant lower mean value of cellular Na+ content (p less than 0.005) and higher mean value of K+ content as compared to males. A significant inverse relationship was found between cellular Na+ content and (Na+-K+)ATPase activity in all subjects studied (p less than 0.05). The results confirm that sex-related differences are present in the erythrocyte membrane so that hemolytic solutions in males and females can expose to a different extent membrane-bound proteins and latent ATPases.     

Effect of cinnamon, clove and some of their constituents on the Na(+)-K(+)-ATPase activity and alanine absorption in the rat jejunum.

The effect of a water extract of some spices on the in vitro activity of the rat jejunal Na(+)-K(+)-ATPase was investigated. Extracts of nutmeg, cinnamon, clove, cumin, coriander, turmeric and caraway all inhibited the ATPase, while anise seed and white pepper exerted no significant effects. The extracts of clove and cinnamon had the most potent inhibitory effect on the intestinal ATPase as compared to extracts of other spices. They also inhibited the in vitro Na(+)-K(+)-ATPase activity in a crude kidney homogenate and the activity of an isolated dog kidney Na(+)-K(+)-ATPase. The alcoholic extract of cinnamon, compared to the aqueous extract, had a stronger inhibitory action on the jejunal enzyme and a lower IC(50) value, which was not significantly different from the one observed with cinnamaldehyde, the major volatile oil present cinnamon, suggesting that in alcoholic extracts cinnamaldehyde is the major inhibitory component. The IC(50) values of eugenol, aqueous clove extract and ethanolic clove extract all fell within the same range and were not significantly different from each other, suggesting that eugenol is the major inhibitory component in both alcoholic and aqueous extracts. Based on the IC(50) values, the order of sensitivity of the enzyme to the spices extracts is as follows: isolated dog kidney ATPase>rat kidney ATPase>rat intestine ATPase. The aqueous extracts of clove and cinnamon also significantly lowered the absorption of alanine from the rat intestine. It was concluded that the active principle(s) in clove and cinnamon can permeate the membrane of the enterocytes and inhibit the Na(+)-K(+)-ATPase that provides the driving force for many transport processes.     

胰岛素对IDDM患者红细胞变形能力改善的研究

目的;观察胰岛素对IDDM患者红细胞变形能力（RCD）的保护效果,初步探讨IDDM微血管并发症发病机理。方法;动态检测我院IDDM患者RCD、膜唾液酸（SA）含量、红细胞膜ATP酶活性及红细胞中超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量。通过胰岛素满意治疗后,重复检测上述指标。结果：糖尿病患者RCD降低;红细胞膜ATP酶活性明显下降,SA含量均显著减少;红细胞中SOD活性降低及MDA水平明显增高;胰岛素有效治疗后上述指标明显改善。结论：I型糖尿病患者RCD明显降低,胰岛素有效治疗可以改善RCD及有效预防微血管并发症的发生。     

Inhibition of renal, cardiac and corneal (Na(+)-K+)ATPase by 12(R)-hydroxyeicosatetraenoic acid

12(R)-hydroxy-5,8,10,14-eicosatetraenoic acid [12(R)-HETE] is one of the major arachidonate metabolites of the corneal epithelial cytochrome P450 system. We studied its inhibitory effect on different preparations of (Na(+)-K+)ATPase. 12(R)-HETE had no effect on ATPase activity in the absence of Na+ and K+. However, it inhibited ouabain-sensitive (Na(+)-K+)ATPase obtained from bovine corneal epithelium, rat kidney and rat heart ventricle in a concentration-dependent manner with an IC50 of 10(-6) M. Its enantiomer, 12(S)-HETE, was inactive at 10(-7) M and 10(-6) M, but it inhibited (Na(+)-K+)ATPase at higher doses, an effect also seen with arachidonic acid. 12(R)-HETE as an endogenous metabolite of arachidonic acid may modulate physiological and pathophysiological processes by affecting (Na(+)-K+)ATPase activities in vivo.     

果糖二磷酸钠镁对缺血突触体乳酸含量及ATP酶活性的影响

目的 :研究果糖二磷酸钠镁 (FDPM)对缺血突触体乳酸含量及ATP酶活性的影响 ,以探讨其脑保护作用机制。方法 :制备正常大鼠脑突触体 ,氧糖剥夺培养建立缺血突触体模型 ,分别加 1.3mmol·L- 1硫酸镁 ,4 .0mmol·L- 11,6 二磷酸果糖 (FDP)及 1.3mmol·L- 1果糖二磷酸钠镁共培养 6 0min ,测定突触体乳酸含量及Na+ K+ATP酶和Ca2 + Mg2 +ATP酶活性。结果 :FDPM可明显降低缺血突触体乳酸含量 ,升高Na+ K+ATP酶和Ca2 + Mg2 +ATP酶活性(P <0 .0 5 ) ,其作用强于FDP的作用。结论 :FDPM保护脑缺血的作用机制可能与其改善脑缺血后能量代谢 ,减轻脑组织酸中毒状态有关     

In vitro response of ATPase activities in tissue subcellular particle preparations to a series of mono-unsaturated C18 fatty acids

The positions of the double bond and the cis/trans configurations of six mono-unsaturated C18 fatty acids (FA) showed selectivity for inhibition and stimulation of ATPase activities of tissue homogenate fractions. The 13,000 g and 100,000 g sediments (fractions B and C respectively) of tissues homogenates were used as sources of Na+-K+ ATPase and of oligomycin-sensitive (OS) and -insensitive (OIS) Mg2+ ATPase activities. Tissue source included bovine brain and rat brain, kidney, heart and liver. Cis mono-unsaturated C18 FA caused an apparent uncoupling of mitochondrial coupling factor F1 (Mg2+ ATPase). This was indicated by the loss of oligomycin and 1,1,1-trichloro-2,2 bis (p-chlorophenyl) ethane (DDT) sensitivity in the presence of 50 microM FA (12-C18:1). Thus, a precipitous decrease in OS-Mg2+ AtPase activity of mitochondria was accompanied by an equally steep increase in OIS-Mg2+ ATPase activity. This was especially apparent in the heart tissue preparation. The uncoupling action of the FA was not observed with the trans mono-unsaturated C18 FA, Na+-K+ ATPase activity from a bovine brain nerve ending particle (B) fraction was also sensitive to 12-C18:1 FA. However, inhibitory response of Na+-K+ ATPase activity were different for OS-Mg2+ ATPase activity. The latter (OS) was not sensitive to the trans 12-C18:1, while the former (Na+-K+) was sensitive to both cis and trans forms of 12-C18:1 and inhibition appeared to be dependent on the position of the double bond.     

萘甲异喹对大鼠心肌细胞Ca~(2+)内流的影响

目的研究萘甲异喹（NI）对大鼠心肌细胞外Ca(2+)内流的影响。方法：应用钙离子荧光指示剂Fura－2检测。结果：NI（3，10μmol·L(-1)）和维拉帕米（0．3μmol·L(－1)）对静息状态下心肌细胞内Ca(2+)浓度无影响，但可浓度依赖地抑制高钾（60mmol·L(-1)）和异丙肾上腺素（lμmol·L(－1)）引起的心肌细胞内Ca(2+)浓度的升高，抑制率分别为29％±6％、49％±9％和26％±6％、40％±8％；NI对两种激动剂作用的抑制百分率无明显差异，而维拉帕米对高钾作用的抑制大于对异丙肾上腺素作用的抑制。结论：NI对心肌细胞电压依赖性钙通道以及和β受体有关的钙通道有阻断作用，NI可能是非选择性钙通道阻滞剂。     

The effect of buthobendin on human erythrocyte membrane ATPases

The effect of buthobendin (CravitenR) on the ATPase activities/total (Na, K, Mg)-ATPase, and the ouabaine-sensitive (Na, K-ATPase) and insensitive (Mg-ATPase) fractions/from human erythrocyte membrane was examined in the presence or absence of liposomes. The activities of both ATPase fractions increased by 250% in the presence of 10 mmol/l phosphatidylcholine. Buthobendin inhibited both ATPases, but especially Na, K-ATPase. This inhibitory effect was much greater in the hydrophobic milieu of liposomes. The inhibitory effect was proportional to the drug concentration and was stereospecifically related only to the 2S, 2'S isomer. Isomer 2R, 2'R and epinephrine used for comparison did not show any similar inhibitory influence. The decrease in ouabaine-sensitive ATPase activity under the influence of buthobendin might cause changes in cation distribution and cell membrane polarization. An inhibitory effect was also observed in vivo, after single iv administration of buthobendin to patients with ventricular arrhythmias and elevated activities of both erythrocyte membrane ATPases. Complete normalization of cardiac rhythm in about 30% of patients was accompanied - in the sensitive group of patients - with a decrease in Mg-ATPase activity without any changes in elevated Na, K-ATPase activity. In the group of patients resistant to buthobendin therapy both ATPases remained unchanged.     

红细胞膜Na~+-K~+-ATP酶活性红细胞膜流动性在新生儿缺氧缺血性脑病中的变化及其意义

目的了解新生儿缺氧缺血性脑病(HIE)中红细胞膜Na+-K+-ATP酶活性、红细胞膜流动性变化及其临床意义。方法选择新生儿科住院的中、重度HIE患儿65例,于急性期、恢复期采血测定红细胞膜Na+K+-ATP酶活性、红细胞膜流动性,并于同期行新生儿神经行为测定(NBNA)评分,对照组选择早期肺炎、咽下综合征、食管闭锁新生儿30例行相同测定,探讨HIE患儿红细胞膜Na+-K+-ATP酶活性、红细胞膜流动性、NBNA的相关关系。采用SPSS13.0统计软件进行统计学分析,组间比较采用单因素方差分析,相关性分析采用直线相关分析,以P<0.05为差异具有统计学意义。结果①中、重度HIE急性期患儿的红细胞膜Na+-K+-ATP酶活性、红细胞膜流动性均明显低于对照组(P<0.01),其中以重度组最低,亦显著低于同期中度组(P<0.05)。恢复期时中度组红细胞膜Na+-K+-ATP酶活性、红细胞膜流动性较同组急性期明显升高(P<0.01),且基本达到对照组水平(P>0.05);②HIE组急性期红细胞膜Na+-K+-ATP酶活性与NBNA评分呈正相关(r=0.507,P<0.05);HIE组恢复期红细胞膜Na+-K+-ATP酶活性与NBNA评分呈正相关(r=0.268,P<0.05);③HIE组急性期红细胞膜流动性与NBNA评分呈正相关(r=0.572,P<0.05);HIE组恢复期红细胞膜流动性与NBNA评分呈正相关(r=0.57,P<0.05)。结论临床检测红细胞膜Na+-K+-ATP酶活性、膜流动性有利于病情早期判断及预后估计。