18β-glycyrrhetinic Acid-induced Apoptosis and Relation with Intracellular Ca^2＋ Release in Human Breast Carcinoma Cells

Objective:To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast carcinoma (MCF-7) cells. Methods: After MCF-7 cells were treated with GA at the concentrations from 50 μmol/L to 250 μmol/L for 24 h, cell viability of proliferation was assessed by MTT assay. After the cells were treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L GA for 24 h, the rates of cell apoptosis were examined by terminal deoxynucleotide transferase mediated dUTP nick-end-labeling method and flow cytometry with Annexin V/propidium iodide fluorescent stain. After the cells treated with 150 μmol/L GA for 24 h, intracellular Ca2+ concentration was measured by Fure-2 fluorescein load method. Results: After the cells were treated with GA at the concentrations from 100 μmol/L to 250 μmol/L, the rates of proliferative inhibition were increased significantly (P<0.05 and P<0.01) in a dose dependent fashion. IC50 of the proliferation inhibition was 234.33 μmol/L. Treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L, the rates of cell apoptosis were increased significantly (P<0.01). Intracellular Ca2+ concentration after treatment with GA was higher evidently than that of control (P<0.05). Conclusion: 18β-glycyrrhetinic acid has the effects of the proliferation inhibition and the apoptotic induction on MCF-7 cells. The rise of intracellular Ca2+ level may be depended on apoptosis induced by GA in MCF-7 cells.

Influence of Panax quinquefolium saponins on increased intracellular Ca^(2+) in PC12 cells

BACKGROUND： Previous studies have demonstrated that intracellular Ca^2＋ （[Ca^2＋]） overload, excitotoxicity, free radical injury, and nitric oxide toxicity are involved in mechanisms of neuronal death in the ischemic brain. OBJECTIVE： To investigate the influence of Panax quinquefo/ium saponins （PQS） on multiple factors-induced Ca^2＋ overload in the rat pheochromocytoma （PC12） cell line. DESIGN, TIME AND SETTING： Intergroup comparison, in vitro study. The experiment was performed at the Heilongjiang Key Laboratory of Anti-fibrosis Biotherapy, Mudanjiang Medical University between November 2007 and April 2008. MATERIALS- In vitro cultured PC12 cells in the logarithmic phase were assigned into blank control, model, and drug treatment groups （10 μmol/L nimodipine; 40 μg/L, 100 μg/L, and 250 μg/L PQS）. Nimodipine was purchased from Jiangsu Yangtze River Pharmacy Group Co., China; PQS （purity 〉 95%, HLPC grade） was provided by School of Basic Medical Sciences, Jilin University. Caffeine, Na2S2O4, L-glutamic acid （Glu）, Fura-2/AM, and calcium ionophore A23187 were purchased from Sigma, USA. METHODS： PC12 cells in the model and drug treatment groups were separately incubated in glucose-free Hank＇s buffered saline solution ＋ Na2S2O4 （2 mmol/L） for 6 hours, Glu （200 μmot/L） plus A23187 （0.05 μmol/L） for 6 hours, KCI （50 mmol/L） for 1 hour, and caffeine （5 mmol/L） for 3 hours to establish models of intracellular Ca^2＋ overload induced by oxygen and glucose deprivation, Glu, A23187, high K＋, or caffeine. In addition, control cells were incubated in high-glucose DMEM culture medium. MAIN OUTCOME MEASURES： [Ca^2＋]i changes in PC12 cells exposed to oxygen-glucose deprivation, Glu, A23187, high K^＋, or caffeine were detected using spectrofluorometer. RESULTS： PQS blocked the [Ca^2＋]i increase induced by oxygen-glucose deprivation, Glu, A23187, high K＋, or caffeine. In particular, high-dose PQS was most effective （P 〈 0.01）. PQS significantly inhibited Glu- or caffeine-induced [Ca^2＋]i increases in the absence of extracellular Ca^2＋, but nimodipine did not. CONCLUSION： PQS blocked intracellular Ca^2＋ overload induced by oxygen-glucose deprivation, Glu, A23187, high K^＋, or caffeine. This mechanism might be involved in the attenuation of neuronal apoptosis following ischemic brain injury.

Differential activation of mitogen-activated protein kinases by γ-irradi-ation in IEC-6 cells: Role of intracellular Ca^(2+)

Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.

The Effect of U50488 on the Cardiac Rhythm and Intracellular Calcium in the Rat Heart.

The effect of U50488, a selective K-opioid receptor agonist, on cardiac rhythm in the isolated perfused rat heart and intracellular calcium ([Ca2+] i) in the single ventricular myocyte were studied. The results showed that U50488 can induce arrhythmias dose-dependently in the isolated perfused rat heart and increase [ Ca2 + ] i in the single ventricular myocyte. The effect of U50488 can be blocked by a selectivek-receptor antagonist, nor-binaltorphimine. The arrhythmogenic effects and the increase of [ Ca2+]i induced by U50488 were blocked by U73122, neomycin and streptomycin, which are selective phospolipase C inhibitors, but not by U73433, the inactive structural analog of U73122. These results demonstrated that the arrhythmogenic effect of cardiac K-receptor is due to activation of phosphoinositol/Ca2+ pathway.

Effects of octreotide on expression of L-type voltage-operated calcium channels and on intracellular Ca^(2+) in activated hepatic stellate cells

Background The contractility of hepatic stellate cells (HSCs) may play an important role in the pathogenesis of cirrhosis with portal hypertension. The aim of this study was to research the effects of octreotide,an analogue of somatostatin,on intracellular Ca 2+ and on the expression of L-type voltage-operated calcium channels (L-VOCCs) in activated HSCs,and to try to survey the use of octreotide in treatment and prevention of cirrhosis with portal hypertension complications. Methods HSC-T_6,an activated HSCs line,was plated on small glass coverslips in 35-mm culture dishes at a density of 1×10 5/ml,and incubated in DMEM media for 24 hours. After the cells were loaded with Fluo-3/AM,intracellular Ca 2+ was measured by Laser Scanning Confocal Microscopy (LSCM). The dynamic changes in activated HSCs of intracellular Ca 2+ ,stimulated by octreotide,endothelin-1,and KCl, respectively,were also determined by LSCM. Each experiment was repeated six times. L-VOCC expression in HSCs was estimated by immunocytochemistry. Results After octreotide stimulation,a signifcant decrease in the intracellular Ca 2+ of activated HSCs was observed. However,octreotide did not inhibit the increases in intracellular Ca 2+ after stimulation by KCl and endothelin-1. Moreover,octreotide did not significantly affect L-VOCC expression. These results suggest that neither L-VOCC nor endothelin-1 receptors in activated HSCs are inhibited by octreotide. Conclusions Octreotide may decrease portal hypertension and intrahepatic vascular tension by inhibiting activated HSCs contractility through decreases in intracellular Ca 2+ . The somatostatin receptors in activated HSCs may be inhibited by octreotide.

Protective Effect of Wenxin Granula on Heart from Myocardial Infarction through Regulating Intracellular Ca^(2+)

Objective To assess the anti-arrhythmic activity and cardioprotective effects of Wenxin Granula,a traditional Chinese formula(consisting of Salviae Miltiorrhizae Radix,Polygonati Rhizoma,Notoginseng Radix et Rhizoma,Nardostachyos Radix et Rhizoma,Angelicae Sinensis Radix,and Succinum),on heart in ischemic-induced myocardial infarction(MI) rats and compare with those of Amiodarone which have been demonstrated in clinic.Methods Rats were randomly divided into Sham-operated(control),MI + Amiodarone [5 mg/(kg.d)](MI),and MI + Wenxin Granula [10 mg/(kg.d)] groups and left anterior descending coronary artery was occluded in each group.After left anterior descending for 12 h,standard lead II of administration electrocardiogram was recorded in order to analyze the occurrence of arrhythmia.After one month,the size of the infarct area of heart was evaluated by TTC staining method and haemodynamic function was assessed to detect the heart function.Laser scanning confocal microscope and the technique of patch clamp were used to detect the intracellular Ca2+([Ca2+]i) and L-type calcium current(ICa-L),respectively.Results Both Wenxin Granula [10 mg/(kg.d)] and Amiodarone [5 mg/(kg.d)] could markedly decrease the incidence of arrhythmia in heart of rats which were subjected to ischemic injury.After one month,Wenxin Granula could significantly decrease mortality to 22.22% and reduce the infarct area(P < 0.05),but Amiodarone did not.The mechanism may involve that Wenxin Granula attenuated [Ca2+]i decreasing in MI rats.Additionally,Wenxin Granula could obviously ameliorate the impaired heart function of MI rats by decreasing the elevated left ventricular end-diastolic pressure and increasing the attenuated maximum change velocity of left ventricular pressure in the isovolumic contraction or relaxation period.On the other hand,electrophysiological experiment results revealed that Wenxin Granula administration one month later also increased the reduced ICa-L density in rat ventricular myocytes in MI rats.The results of LSCM showed that Wenxin Granula could recover the amplitude of [Ca2+]i decreased by heart failure during long term.Conclusion Wenxin Granula could not only inhibit the incidence of arrhythmia but also decrease the mortality,which was accompanied by recovering the amplitude of [Ca2+]i.This protective effect of Wenxin Granula may partially be mediated through changing ICa-L as well as increasing [Ca2+]i.

Relationship of Intracellular Free Ca^(2+) Concentration and Calcium-activated Chloride Channels of Pulmonary Artery Smooth Muscle Cells in Rats under Hypoxic Conditions

To investigate the relationship between intracellular free Ca^2＋ concentration （[Ca^2＋ ]i ） and calcium-activated chloride （Clca） channels of pulmonary artery smooth muscle cells （PASMCs） in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2＋ indicator Fura-2/AM was used to observe [Ca^2＋ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid （NFA） and indaryloxyacetic acid （IAA-94） exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2＋ ]i was increased. Under normoxic condition, [Ca^2＋ If was （123.634-18.98） nmol/ L, and in hypoxic condition, [Ca^2＋]i wag （281. 754-16.48） nmol/L （P〈0. 01）. Under normoxic condition, [Ca^2＋ ]i showed no significant change and no effect on Clca channels was observed （P〉 0. 05）. Chronic hypoxia increased [Ca^2＋ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2＋ ]i from （281.75± 16.48） nmot/L to （117.66 ±15.36） nmol/L （P〈0.01）. MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency （A value） from 0. 459±0. 058 to 0. 224±0. 025 （P〈0. 01）. Hypoxia increased [Ca^2＋ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2＋ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.

Ca^2＋信号参与铝诱导黑麦根系分泌有机酸的调控

【目的】揭示铝诱导根系分泌有机酸的机制,探讨胞质钙信号对铝诱导黑麦根系分泌有机酸的调控作用。【方法】采用药理学研究方法和激光共聚焦扫描显微技术探讨铝胁迫下根尖胞质游离钙离子浓度([Ca2+]cyt)及其与有机酸分泌的关系。【结果】铝不仅诱导黑麦根系分泌柠檬酸和苹果酸,而且使根尖细胞Ca2+的荧光强度增强、波动加剧。铝引起的根尖细胞Ca2+荧光强度的变化在受Ca2+通道抑制剂异搏定、胞内Ca2+通道阻断剂辽红干扰后,显著减少了铝诱导的有机酸分泌。铝诱导的根尖[Ca2+]cyt的升高及有机酸分泌还受CaM阻断剂三氟拉嗪的干扰和抑制。钙螯合剂EGTA处理不仅减弱了铝诱导的Ca2+荧光信号、加大了Ca2+信号的波动幅度,而且显著抑制铝诱导的柠檬酸分泌。此外,在铝胁迫下,根系有机酸分泌受阴离子通道抑制剂尼氟灭酸的抑制。【结论】根尖[Ca2+]c可能是介导铝诱导黑麦根系分泌有机酸的胞内信号因子,而质膜上的阴离子通道可能是铝诱导的钙信号传导途径中的下游效应器。

18β-甘草次酸诱导人乳腺癌细胞凋亡及其细胞内Ca^(2+)水平的变化

背景与目的:18-甘草次酸是甘草的重要成分,近年来的研究发现18-甘草次酸具有抑制人淋巴细胞性白血病、肝癌和肺癌的细胞增殖。本研究探讨18-甘草次酸对人乳腺癌MCF-7细胞诱导凋亡的作用。目前研究已证实细胞内游离Ca2+浓度([Ca2+]i)的动态变化在诱发细胞凋亡过程的多个环节中起重要作用,因此本研究也探讨由18-甘草次酸诱导的MCF-7细胞凋亡发生与[Ca2+]i变化的关系。方法:用50~250μmol/L浓度梯度的18β-甘草次酸处理MCF-7细胞24h,用MTT比色法测定细胞增殖能力。100μmol/L和150μmol/L 18β-甘草次酸处理细胞24 h,用末端脱氧核苷酸转移酶介导dUTP末端标记法、Annexin V流式细胞仪法和单细胞凝胶电泳法检测凋亡细胞。150μmol/L 18β-甘草次酸处理细胞24 h,用Fura-2荧光负载方法测定[Ca2+]i的变化。分别用100μmol/L BAPTA-AM和0.5 mmol/L EGTA与150μmol/L 18β-甘草次酸联合处理MCF-7细胞24 h,用单细胞凝胶电泳法检测凋亡细胞。结果:从100μmol/L 18β-甘草次酸浓度起对MCF-7细胞的增殖抑制率显著升高(P<0.01和P<0.05),呈剂量依赖性,半增殖抑制浓度(IC 50)为234.33μmol/L。100μmol/L和150μmol/L 18β-甘草次酸使细胞凋亡率显著升高(P<0.01和P<0.05);18β-甘草次酸处理组的[Ca2+]i也明显高于对照组(P<0.05)。18β-甘草次酸与BAPTA-AM联合处理组和18β-甘草次酸与EGTA联合处理组的凋亡率均明显低于单纯的150μmol/L18β-甘草次酸处理组(P<0.05和P<0.01)。结论:18-甘草次酸具有抑制MCF-7细胞增殖和诱导其凋亡的作用,而18-甘草次酸诱导MCF-7细胞凋亡的作用在抑制该细胞增殖方面起主要作用。18-甘草次酸诱导MCF-7细胞凋亡依赖于细胞内Ca2+水平上调,而细胞外Ca2+内流是导致细胞内Ca2+水平上调的原因之一。

广枣总黄酮对大鼠心室肌细胞IC_a、I_(to)和细胞[Ca^(2+)]_i的影响

目的 观察广枣总黄酮对大鼠心室肌细胞L 型钙通道电流 (ICa)和瞬时外向钾通道电流 (Ito)以及对心肌细胞内游离钙浓度 ([Ca2 + ]i)的影响 ,探讨其抗心律失常作用机制。方法 全细胞膜片钳记录大鼠心室肌细胞ICa、Ito,激光共聚焦显微镜观察细胞 [Ca2 + ]i 的变化。结果 在钳制电压- 4 0mV ,实验电压 - 4 0～ +5 0mV时 ,广枣总黄酮 10 0mg·L-1对心室肌细胞ICa无显著影响 ;在钳制电压 - 6 0mV ,实验电压 - 4 0～ +5 0mV时显著抑制瞬时外向钾通道Ito(P <0 0 5 ) ;而激光共聚焦显微镜结果显示广枣总黄酮在 5 0、10 0、2 0 0mg·L-1却降低缺氧复氧心肌细胞收缩期和静息期[Ca2 + ]i 的浓度。结论 广枣总黄酮对心肌细胞ICa无显著影响 ,可显著抑制瞬时外向钾通道Ito,并可明显降低心肌细胞收缩期和静息期细胞 [Ca2 + ]i 浓度。这可能是其抗心律失常和保护缺血心肌的主要作用机制。

小檗碱对培养大鼠神经细胞内游离Ca^(2+)的影响

以Ｆｕｒａ２／ＡＭ为细胞内钙离子的荧光指示剂，用ＡＲＣＭＭＩＣ阳离子测定系统，直接测定了体外培养的新生大鼠神经细胞内游离钙（［Ｃａ２＋］ｉ）值，并观察了小檗碱（Ｂｅｒ）的影响。结果表明，Ｂｅｒ对神经细胞静息［Ｃａ２＋］ｉ无明显影响，Ｂｅｒ１～１００μｍｏｌ·Ｌ－１能剂量依赖地抑制去甲肾上腺素和Ｈ２Ｏ２引起的［Ｃａ２＋］ｉ升高，其ＩＣ５０分别为３９．９和１７．９μｍｏｌ·Ｌ－１。高剂量Ｂｅｒ（１０～１００μｍｏｌ·Ｌ－１）能抑制高Ｋ＋引起的［Ｃａ２＋］ｉ升高。姐果提示，Ｂｅｒ对去甲肾上腺素，高Ｋ＋及Ｈ２Ｏ２引起的［Ｃａ２＋］ｉ升高的抑制作用可能是其抗脑缺血作用机制之一。

大黄酸对IL-2诱发T淋巴细胞增殖和细胞[Ca^(2＋)]_i变化的作用

研究大黄酸对IL-2引起大鼠T淋巴细胞增殖和细胞内[Ca^(2+)]_i变化的影响.采用MTT法检测细胞增殖,用单细胞钙成像系统记录胞内游离Ca^(2+)浓度([Ca^(2+)]_i).结果表明,大黄酸对IL-2引起的细胞增殖有显著抑制作用,且抑制效果与剂量有关;IL-2引起[Ca^(2+)]_i升高,并持续维持高[Ca^(2+)]_i水平,[Ca^(2+)]_i升高的机制包括胞内Ca^(2+)释放和胞外Ca^(2+)内流;大黄酸显著抑制IL-2引起的[Ca^(2+)]_i升高.结果提示大黄酸可抑制T淋巴细胞增殖,作用机制可能与抑制细胞内[Ca^(2+)]_i升高相关.

环维黄杨星D对分离大鼠心室肌细胞内Ca^(2+)和L型钙电流的影响

目的 研究环维黄杨星D(CD)对大鼠心室肌细胞内Ca2 + 动员和L型钙电流 (ICa L)的影响。方法 采用全细胞膜片钳和激光扫描共聚焦显微术研究CD对心肌细胞ICa L以及氯化钾、咖啡因诱发心肌细胞内Ca2 + 动员的影响。结果 CD浓度依赖性抑制ICa L。指令电压为 10mV时 ,1和 10 μmol·L- 1 CD分别使ICa L 电流密度从 (- 9 9±1 8)pA pF降至 (- 6 4± 1 4 )pA pF和 (- 4 2± 0 6 )pA pF。共聚焦实验显示 1和 10 μmol·L- 1 CD不影响静息心肌细胞 [Ca2 + ]i,对氯化钾诱发 [Ca2 + ]i升高水平无明显抑制作用 ;咖啡因引起的细胞内Ca2 + 动员可被CD进一步增强。结论 CD浓度依赖性抑制大鼠心室肌细胞ICa L,并有促进咖啡因诱发心肌细胞内Ca2 +

单细胞内Ca^（2＋）时空变化的激光共聚焦显微测定

应用激光扫描共聚焦显微系统（ＬＳＣＭ）和Ｆｌｕｏ－３／ＡＭ荧光探剂标记技术，测定了单个活细胞胞内游离Ｃａ２＋的动态变化与立体分布影像．结果显示，在３７℃，Ｆｌｕｏ－３／ＡＭ终浓度为６μｍｏｌ／Ｌ的条件下，Ｃ５７ＢＬ／６Ｊ小鼠巨噬细胞负载１ｈ左右即可获得良好的标记效果．相反，若探剂浓度太高或负载时间太长，胞内荧光强度太强，影响在共聚焦显微镜镜下分辨细胞内结构．因此用ＬＳＣＭ研究细胞内游离Ｃａ２＋变化时，荧光探剂的负载应以获得最适荧光信号而不是以最大荧光强度为标准．上述方法在其他如平滑肌细胞、卵母细胞中的测定亦获得满意的结果，这对进一步研究各种生理和病理条件下细胞内Ｃａ２＋信号的动态变化、与跨膜Ｃａ２＋梯差的关系及对活细胞功能活动的调节提供了一种可行的、直观的研究手段。

神经肽Y经Ca^2＋/CaM依赖的钙调神经磷酸酶途径诱导心肌细胞肥大

目的观察神经肽Y(NPY)诱导心肌细胞肥大效应,及Ca2+/CaM依赖的钙调神经磷酸酶(CaN)途径在其中起的作用。方法用NPY(10、100nmol)刺激心肌细胞,用环胞素A(CsA)特异性抑制CaN活性。测定心肌细胞蛋白合成速率(3H-Leu掺入量)、CaN-蛋白表达、c-junmRNA表达、CaN酶活性、细胞内游离钙含量。结果(1)在100nmolNPY作用下,心肌细胞3H-Leu掺入量及c-junmRNA表达量均较对照组显著增高(P<0.05,P<0.001)。NPY+CsA组和对照组相比无显著差别。(2)在100nmolNPY作用下,NPY组心肌细胞内CaN酶比活力、CaN-α表达、胞浆及核内钙含量较对照组显著增高(P<0.05,P<0.05,P<0.001,P<0.001)。结论NPY可刺激心肌细胞肥大,CaN信号途径在其中起重要作用。

绞股蓝总黄酮对缺氧心肌细胞损伤标记物及细胞内游离Ca^2＋浓度的影响

探讨绞股蓝总黄酮(TFG)对缺氧心肌细胞损伤标记物及细胞内游离Ca2+浓度的影响.在离体乳鼠心肌细胞原代培养基础上制备心肌细胞缺氧模型,随机分为正常对照组、缺氧损伤组和绞股监总黄酮干预缺氧损伤组.分别测定各组心肌培养基中乳酸脱氢酶(LDH)、肌钙蛋白I(cTn I)的含量,心肌细胞内游离Ca2+的浓度(荧光探针法).缺氧损伤组心肌培养基中LDH和cTnI的含量及心肌细胞内游离Ca2+浓度较正常对照组明显增加(P<0.05或0.01);经TFG干预后细胞培养基中LDH利cTnI的含量及心肌细胞内游离Ca2+浓度较缺氧损伤组明显降低(P<0.05或0.01).TFG对缺氧心肌细胞具有保护作用,其机理可能与减轻心肌细胞内钙超负荷有关.

慢性染铅对大鼠海马区神经细胞Ca^(2+)浓度及Ca^(2+)-ATP酶活性的影响

目的：观察慢性染铅对大鼠海马区神经细胞Ｃａ２＋浓度及Ｃａ２＋－ＡＴＰ酶活性的影响。方法：用０．１５％醋酸铅饲养大鼠建立慢性染铅动物模型，参照Ｄｉｌｄｙ法和徐友涵法测定海马神经细胞Ｃａ２＋浓度及Ｃａ２＋－ＡＴＰ酶活性。结果发现：细胞内Ｃａ２＋浓度，染铅组（２０３．８３±３０．５０）ｎｍｏｌ／Ｌ，对照组（９７．６２±１９．８３）ｎｍｏｌ／Ｌ，ｔ＝８．３１Ｐ＜０．００５；Ｃａ２＋－ＡＴＰ酶活性，染铅组（３２６．４２±４０．０６）ｎｍｏｌ（Ｐｉ）·ｍｇ－１·ｍｉｎ－１，对照组（２５３．０７±２５．４０）ｎｍｏｌ（Ｐｉ）·ｍｇ－１·ｍｉｎ－１，ｔ＝３．５４，Ｐ＜０．０１。结论：慢性染铅可使大鼠海马区神经细胞内Ｃａ２＋浓度升高。

高钾离子引起PC12细胞内游离Ca^(2+)浓度升高的机制

目的：分析高钾离子（Ｋ＋）引起ＰＣ１２细胞内游离钙离子浓度（［Ｃａ２＋］ｉ）升高的可能机制。方法：利用ＭｉｒａＣａｌＩｍａｇｅＳｙｓｔｅｍ检测［Ｃａ２＋］ｉ，Ｃａ２＋荧光探针为Ｆｕｒａ－２／ＡＭ。结果：（１）ＫＣｌ浓度为３０～１００ｍｍｏｌ／Ｌ时，可剂量依赖性地诱导ＰＣ１２细胞［Ｃａ２＋］ｉ升高；（２）在细胞外无Ｃａ２＋时，高Ｋ＋对ＰＣ１２细胞［Ｃａ２＋］ｉ无影响；（３）Ｌ－型电压门控钙通道阻滞剂维拉帕米、地尔硫和硝苯地平的浓度分别为５×１０－５，１×１０－４和５×１０－３ｍｏｌ／Ｌ时，可完全阻断高Ｋ＋诱导的ＰＣ１２细胞［Ｃａ２＋］ｉ升高，但Ｎ－型电压门控钙通道阻滞剂ω－ｃｏｎｏｔｏｘｉｎＧＶＩＡ在浓度为１×１０－６ｍｏｌ／Ｌ时，对高Ｋ＋诱导的ＰＣ１２细胞［Ｃａ２＋］ｉ升高没有影响；（４）５×１０－５ｍｏｌ／Ｌ维拉帕米对细胞外由无Ｃａ２＋到有Ｃａ２＋过程引起的［Ｃａ２＋］ｉ升高无抑制作用。结论：高Ｋ＋引起ＰＣ１２细胞［Ｃａ２＋］ｉ升高以细胞质膜上Ｌ－型电压门控Ｃａ２＋通道开放为基础。

He-Ne激光照射对成纤维细胞内[Ca^(2+)]_i浓度影响的流式细胞计测定

目的：ＨｅＮｅ激光照射治疗的机理不明，激光照射引起细胞内Ｃａ２＋水平变化，为治疗机理提供理论依据。方法：ＨｅＮｅ激光照射引起鼠成纤维细胞Ｌ９２９内［Ｃａ２＋］ｉ的变化，用ＨＯ３４２对细胞ＤＮＡ活性染色，Ｆｌｕｏ３ＡＭ对细胞内Ｃａ２＋染色，利用ＦＣＭ同时定量分析细胞ＤＮＡ和细胞内Ｃａ２＋的变化。结果：激光照射１５ｍｉｎ（光剂量１１．８１Ｊ／ｃｍ２后，ＦＣＭ分析可见ＤＮＡ分布直方图右移，表明成纤维细胞进入周期加快，二维点阵图设窗分析，分为低Ｃａ２＋区和高Ｃａ２＋区，与对照组相比，成纤维细胞在周期进程中，在低Ｃａ２＋区，Ｇ１期细胞变化不大，Ｓ期和Ｇ２＋Ｍ期细胞内［Ｃａ２＋］ｉ水平增加，但是在高Ｃａ２＋区，细胞的Ｇ１、Ｓ和Ｇ２＋Ｍ期细胞内［Ｃａ２＋］ｉ均明显增加。结论：许多研究者用化学因子和药物刺激，使细胞随着周期进程，细胞内［Ｃａ２＋］ｉ明显增加，出现复杂变化。本实验结果表明ＨｅＮｅ激光照射成纤维细胞，引起细胞周期进程中细胞内［Ｃａ２＋］ｉ出现明显变化。

原发性高血压患者红细胞膜 Ca-ATP 酶活性

本文报告60例原发性高血压患者男44,女16,平均年龄49.2±7.3岁,平均血压(MAP)16.03±1.12kPa(120.2±8.4mmHg)红细胞膜 Ca-ATP 酶活性,以同年龄组60名健康人为对照:男41,女19,平均年龄40.7±13.1岁,MAP12.43±0.63kPa(93.2±4.8mmHg)。结果表明,高血压患者红细胞膜 Ca-ATP 酶活性0.44±0.088μmolPi/mgprot·h^(-1),明显低于对照组0.64±0.052μmol Pi/mg prot·h^(-1),P<0.001。该酶活性变化与 MAP 呈明显负相关。本研究结果提示,质膜 Ca-ATP 酶活性减低对于细胞内游离 Ca^(2+)浓度提高及高血压发病可能起一定的作用。