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.

EFFECTS OF PDGF-BB ON INTRACELLULAR CALCIUM CONCENTRATION AND PROLIFERATION IN CULTURED GLOMERULAR MESANGIAL CELLS

Objective To investigate the relationship between the alteration of intracellular calcium concentration and proliferation in cultured glomerular mesangial cells. Methods Rat mesangial cells were cultured. lntracellular calcium concentrations were measured by confocal Laser Scanning Microscopy and Fura-3 fluorescence dyeing techniques. Cell growth was measured by MTT assay. Results PDGF-BB increased intracellular calcium concentrations in a dose-dependent manner, and at the same time promote the proliferation of mesangial cells. After preincubation with calcium channel blocker nifedipine or angiotensin converting enzyme inhibitor captopril, both the increase of intracellular calcium concentrations and cell proliferations induced by PDGF-BB were inhibited. Tripteriglum Wilfordii Glycosides （TMG） significantly inhibited the mesangial cell proliferations, but it had no significant effect on intracellular calcium concentrations. Conclusion There was a positive relationship between the elevation of intracellular calcium concentration and cell proliferation in glomerular mesangial cells, but the increase of intracellular calcium concentrations wasn＇t the only way for proliferation.

Effects of Total Flavonoids ofHippophae RhamnoidesL.on Intracellular Free Calciumin Cultured Vascular Smooth Muscle Cells of Spontaneously Hypertensive Rats and Wistar-Kyoto Rats

To explore the effects of total flavonoids of Hippophae rhamnoides L. （TFH） quercetin （Que） and isorhamnetin （Isor） on the intracellular free calcium （[Ca^2＋]） in vascular smooth muscle cells （VSMC） of spontaneously hypertensive rats （SHR） and Wistar-Kyoto rats （WKY）. Metheds： Fluo 3-acetoxymethylester（Fluo-3/AM） was used to observe the effects of TFH （100mg/L） and its essential monomers, namely Que （10^-4mol/L） and Isor （10^-4mol/L） on changes of [Ca^2＋]1 in cultured SHR and WKY VSMC （abbr. to Ca-SHR ＆ Ca-WKY） following exposure to high K^＋, norepinephrine （NE） and angiotensin Ⅱ （AngⅡ）, and to compare with the effects of verapamil （Ver）. Results： （1） TFH, Que and Isor had inhibitory effects on resting Ca-SHR （P〈0.05）, but had no significant effects on Ca-WKY （P〉0.05）. （2） High K^＋ could increase Ca-SHR more significantly than Ca-WKY （P〈0.05）; TFH, Que and Isor could inhibit the elevation of [Ca^2＋]1 induced by high K^＋ -depolarization, with the effects similar to that of Ver, and the effect on Ca-SHR was more significant than that on Ca-WKY （P〈0.05）. （3） NE and Ang Ⅱ could increase Ca-SHR more significantly than Ca-WKY （P〈0.05）, TFH, Que and Isor had remarkably inhibitory effect on the elevation of Ca-SHR and Ca-WKY induced by NE or Ang Ⅱ. （4） In the absence of extracellular Ca^2＋ , TFH, Que and Isor also had certain inhibitory effect on Ca-SHR and Ca-WKY induced by NE, and the effect on the former was more significant than that on the latter（P〈0.05）. Ceaclusiea： TFH, Que and Isor might decrease the levels of [Ca^2＋], in VSMCs by blocking both voltage-dependent calcium channels （VDC） and receptoroperated calcium channels （ROC） in physiological or pathological state, which may be one of the important mechanisms of their hypotensive and protective effects on target organs in patients with hypertension.

High concentration of calcium ions in Golgi apparatus

The interphase NIH3T3 cells were vitally fluorescentstained with calcium indicator fluo-3 and Glogi probe C6NBD-ceramide, and then the single cells were examined by laser scanning confocal microscopy (LSCFM) for subcellular distributions of Ca2+ and the location of Golgi apparatus. In these cells, the intracellular Ca2+ were found to be highly concentrated in the Golgi apparatus. The changes of distribution of cytosolic high Ca2+ region and the Golgi apparatus coincided with the cell cycle phase.In calcium free medium, when the plasma membrane of the cells which had been loaded with fluo-3/AM were permeated by digitonin, the fluorescence of the Golgi region decreased far less than that of the cytosol. Our results indicated that the Glogi lumen retained significantly high concentration of free calcium.

Rapid Inhibition of the Glutamate-induced Increase of Intracellular Free Calcium by Magnesium in Rat Hippocampal Neurons

By using Fura-2/AM, the effects of magnesium (Mg 2+) on the glutamate-induced increase of intracellular free calcium ([Ca 2+]i) in the cultured hippocampal neurons and the features were investigated by integrated photoelectric detecting system. The experiments were designed to three groups (The drug was spit to the cells for 20 s): Group A receiving 1×10 —5 mol/L glutamate; Group B receiving 1×10 —5 mol/L glutamate and1×10 —5 mol/L Mg 2+ simultaneously; Group C receiving 1×10 —5 mol/L glutamate again after [Ca 2+]i in group B back to the baseline. The results showed that in group A, [Ca 2+]i was obviously increased. In group B, the changes in [Ca 2+]i and the peak value were significantly decreased. Moreover, the elevation of Phase 1 was slowed down and Phase 2 was shortened to some extent, and the plateau phase between them was relatively prolonged. In group C, calcium oscillation similar to that in group A occurred, but both the Phase 1 and Phase 2 were shortened and the △[Ca 2+]i was slightly decreased. It was suggested that Mg 2+ could quickly inhibit the rise of [Ca 2+]i induced by glutamate in the cultured hippocampal neurons in rats.

Both Hypoxic Endothelial Cell Conditioned Medium and Hypoxia Elevate Intracellular Free Calcium in Pulmonary Artery Smooth Muscle Cells

By using Ca2+ -sensitive fluorescent probe, Fura-2 , the effects of endothelial cell-conditioned medium and hypoxia on intracellular free calcium ( [Ca2+]i) in cultured pulmonary artery smooth muscle cell (PASMC) were studied. Normoxic porcine pulmonary artery endothelial cell-conditioned medium (NPAECCM) obviously elevated [Ca2+]i in PASMC,whereas the hypoxic porcine pulmonary artery endothelial cell conditioned medium (HPAECCM)significantly elevated [Ca2+]i in PASMC much more than NPAECCM. Both the effects of NPAECCM and HPAECCM were dependent on the cultured endothelial cell extracellular calcium concentrations, ranged from 1.8 mmol/L to 2. 4 mmol/L.Meanwhile, hypoxia directly increased, which was partially inhibited by verapamil,[Ca2+]i in PASMC through Ca2+ influx pathway.The data suggest that the augmented regulation of endothelial cell on PASMC via Ca2+ second messenger system and the hypoxia-induced Ca2+ influx into PASMC,particularly the former, may be components of mechanisms underlying hypoxic pulmonary vasoconstriction and chronic pulmonary hypertension.

STUDY ON THE PLATELET INTRACELLULAR FREE Ca^(2+) IN NORMAL PREGNANCY

This study measured platelet intracellular free calcium (PFCa 2+ ) of 1003 normal pregnancies in different trimester. The purpose of this study was to find the alteration of PFCa 2+ in normal pregnancy, to provide scientific basis for forecasting and preventing PIH (pregnancy induced hypertension). The results showed that the PFCa 2+ concentration was stable and slightly increased with the progression of gestational weeks.

Effects of simulated microgravity on the alkaline phosphatase activity and intracellular calcium concentration of cultured chondrocytes

The effects of simulated microgravity on matrix mineralization of chondrocytes were examined using cultured chicken embryonic chondrocytes as the model. In four days, there was a time course decrease in alkaline phosphatase activity of chondrocytes, a marker of matrix mineralization.Meanwhile, in two days, there was a significant drop in intracellular calcium concentration in contrast to the control. These results indicate that simulated microgravity can suppress matrix calcification of cultured chondrocytes, and intracellular calcium may be involved in the regulation of matrix calcification as the second messenger.

脱氢紫堇碱对正常和低氧豚鼠心肌细胞内钙的影响

目的 :探讨脱氢紫堇碱 (dehydeocorydaline,DHC)及维拉帕米 (verapamil,Ver)对豚鼠心肌细胞内游离钙浓度([Ca2 + ] i)变化的影响。方法 :采用离体豚鼠心脏Langendorff法灌注 ,用荧光指示剂方法 (Fure 2 /AM)标记心肌([Ca2 + ] i)变化。观察低氧后心肌 [Ca2 + ] i 的变化。结果 :①正常氧状态心肌 [Ca2 + ] i 均值为 (1 2 0 .5± 8.3)nmol/L(n =2 0 ) ;②正常氧条件下 ,DHC、Ver均使心肌 [Ca2 + ] i 明显下降。 (3)低氧状态下 ,心肌 [Ca2 + ] i 增加与缺氧时间(程度 )直线相关 (r=0 .98)。④DHC对低氧后心肌 [Ca2 + ] i 增加明显减缓。结论 :DHC在正常氧、低氧条件下阻止心肌细胞内钙超载 。

黄芪多糖对小鼠免疫细胞信号转导相关分子的影响

为探讨黄芪多糖(APS)免疫调节的作用机理,观察了黄芪多糖对小鼠腹腔巨噬细胞一氧化氮(NO)生成、对体外培养的小鼠脾脏淋巴细胞内游离钙离子水平和蛋白激酶C(PKC)活性的影响。结果显示黄芪多糖能明显促进小白鼠腹腔巨噬细胞NO生成,显著升高小鼠脾淋巴细胞内游离钙离子的水平,引起细胞PKC活性明显升高。提示黄芪多糖通过NO介导信号传递通路,调节脾淋巴细胞内游离钙离子的浓度,升高细胞蛋白激酶活性而影响机体免疫细胞的信号转导,发挥其免疫调节作用。

小檗碱对培养大鼠神经细胞“缺血”性损伤的保护作用

目的观察小檗碱（Ｂｅｒ）对缺氧／缺糖培养引起的大鼠脑皮层神经元“缺血”性损伤的保护作用，并初步探讨其作用机制。方法体外培养大鼠胎鼠脑皮层神经元，以缺氧加缺糖培养作为细胞“缺血”性损伤模型，观察Ｂｅｒ对神经元“缺血”性损伤的保护作用。结果Ｂｅｒ５，２５μｍｏｌ·Ｌ－１能显著降低神经细胞“缺血”性损伤时的细胞死亡率，减少乳酸脱氢酶（ＬＤＨ）的漏出，改善细胞形态，对缺氧／缺糖诱导的神经细胞内游离钙浓度（［Ｃａ２＋］ｉ）的升高有明显的抑制作用，并能减少脂质过氧化物生成，提高谷胱甘肽（ＧＳＨ）含量及超氧化物歧化酶（ＳＯＤ）活性。结论Ｂｅｒ对培养大鼠脑皮层神经元“缺血”性损伤具有保护作用，其机制可能与Ｂｅｒ抑制“缺血”性损伤诱导的［Ｃａ２＋］ｉ异常升高，减少脂质过氧化物生成，增加抗氧化物质的含量有关。

极低频弱磁场对PC-12瘤细胞胞内游离钙离子浓度的影响

采用极低频弱磁场对鼠嗜铬细胞瘤 PC- 12株系细胞进行照射 ,利用显微荧光技术动态监测胞内游离钙离子浓度 ([(Ca2 + ]i)的变化 ,实验结果表明 :5 0 Hz,10 0 μT的正弦磁场照射引起 [Ca2 + ]i 明显升高 ;而在同等强度的静磁场和 2 0 0 0 Hz正弦磁场照射下 ,[Ca2 + ]i 基本维持不变。进一步的实验说明 [Ca2 + ]i 的升高部分源于细胞外 Ca2 +的跨膜内流 ,部分源于胞内钙库的释放。证实了一定强度下特定频率的极低频弱磁场能够影响钙离子的跨膜运输和胞内钙库的释放 。

人参皂甙Rg1对缺氧豚鼠心肌细胞游离钙浓度降低作用的研究

目的 :探讨人参皂甙 (ginsenosides,Gin)单体Rgl及维拉帕米 (verapamil,Ver)对豚鼠心肌细胞内游离钙浓度 ([Ca2 + ]i)变化的影响。方法 :采用离体豚鼠心脏Langendorff法灌注 ,胶原酶I型分离心肌细胞 ,用荧光指示剂方法 (Fura 2 /AM)标记心肌 ([Ca2 + ]i)变化。将心肌细胞悬液分为 3组 :对照组、Rgl组和Ver组。观察缺氧后心肌[Ca2 + ]i 的变化。结果 :(1)正常氧状态心肌 [Ca2 + ]i 均值为 (12 5 .4± 10 .3)nmol/L(n =2 0 )。 (2 )缺氧状态下 ,心肌[Ca2 + ]i 增加与缺氧时间 (程度 )直线相关 ,相关系数r为 0 .98左右。 (3)Rgl对缺氧后心肌 [Ca2 + ]i 增加明显延缓。结论 :Rgl在缺氧条件下 ,使心肌 [Ca2 + ]i 明显下降 ,从而阻止心肌细胞内钙超载 ,其作用与Ver相似 。

灵芝多糖对小鼠腹腔巨噬细胞胞浆游离Ca^(2+)浓度的影响

目的：探讨灵芝多糖（ＧＬＰ）对免疫细胞信号转导过程的影响。方法：采用激光扫描共聚焦显微镜（ＬＳＣＭ） 技术，动态监测ＧＬＰ均一体组分ＧＬＢ７ 对小鼠腹腔巨噬细胞（ＭΦ）胞浆游离Ｃａ２＋ 浓度（［Ｃａ２＋］ｉ）的影响。结果：ＧＬＢ７（２０μｇ·ｍｌ－１） 引起小鼠腹腔ＭΦ中［Ｃａ２＋］ｉ 明显升高，升高值为（２４８ ±１８） ％（ｎ ＝６）；ＧＬＢ７ 引起小鼠腹腔ＭΦ外钙内流及ＭΦ内ＩＰ３ 敏感和ＩＰ３ 非敏感钙池释放Ｃａ２＋ ，［Ｃａ２＋］ｉ 升高值分别为（７６±１０） ％ ，（５８ ±１０） ％ ，（４１ ±８）％ （ｎ ＝ ６） ；ＧＬＢ７ 对ＭΦ［Ｃａ２＋］ｉ 的影响与Ｋ＋ 通道及其引起的膜电位变化无关。结论：ＭΦ是灵芝多糖作用的靶细胞；ＧＬＢ７ 引起ＭΦ中［Ｃａ２＋］ｉ 快速升高，可能是灵芝多糖产生作用的重要途径。

蚓激酶的心肌保护作用及机制

目的研究蚓激酶对心肌缺血的保护作用,并进一步探讨其可能机制。方法采用结扎大鼠左冠状动脉前降支制备急性心肌缺血模型,观察蚓激酶对心肌缺血的保护作用;应用全细胞膜片钳和激光扫描共聚焦技术,研究蚓激酶对L-型钙电流(ICa-L)和细胞内游离钙离子浓度的影响。结果蚓激酶80,40和20 mg.kg-1剂量组均可缩小心肌梗死面积。膜片钳研究结果表明,当刺激电压为+10 mV时,10和50μmol.L-1蚓激酶使ICa-L降低共聚焦结果显示,在静息状态下,10μmol.L-1蚓激酶对[Ca2+]i无明显影响;但10μmol.L-1蚓激酶对60 mmol.L-1KC l诱导的[Ca2+]i升高却有明显抑制作用,并且在整个实验过程中(240 s)并未出现明显的峰值。结论蚓激酶对大鼠心肌缺血具有保护作用,其机制可能与抑制ICa-L及下调[Ca2+]i有关。

灵芝多糖对小鼠T细胞胞浆游离Ca^(2+)浓度和胞内pH的影响

目的通过考察灵芝多糖（ＧＬＰ）对免疫细胞信号转导过程的影响，探讨ＧＬＰ免疫调节作用机制。方法采用激光扫描共聚焦显微镜（ＬＳＣＭ）技术，动态监测ＧＬＰ均一体组分ＧＬＢ７对小鼠Ｔ细胞胞浆游离Ｃａ２＋浓度（［Ｃａ２＋）和胞内 ｐＨ（［ｐＨ］ｉ）的影响。结果 ＧＬＢ７（２０ｍｇ·Ｌ－１）引起小鼠 Ｔ细胞中［Ｃａ２＋］；和［ｐＨ］；明显升高，１ｍｉｎ即分别升高至３３４．７０％±１６，４％（ｎ＝３）、１７１．６％ ± １０．４％（ｎ＝３），之后一直分别维持在该平台期，至 １０ ｍｉｎ仍维持高峰水平。加入ＥＣＴＡ和 ｖｅｒａｐａｍｉｌ处理后， １０ ｍｉｎ ＧＬＢ７ 引起 Ｔ细胞［Ｃａ２＋］；和［ｐＨ］；分别升高为 ２０２．４％± １３．６％（ｎ＝３）。１４０．２％±７．８％（ｎ＝３），与正常对照组比较差异有显著性（Ｐ＜０．０1）。以 ＥＧＴＡ和 ｖｅｒａｐａｍｉｌ处理后，再分别以 ｈｅｐ－ｅｒｉｎ和 ｐrocaine处理细胞 １０ ｍｉｎ，之后以 ＧＬＢ７刺激Ｔ细胞，１０ｍｉｎ［Ｃａ２＋］ｉ值分别为１５１．５％±９．４％（ｎ＝３）、１４３．２％± ８．１ ％（ ｎ＝ ３），与 ＥＧＴＡ和 ｖｅｒａｐａｍｉｌ处理组相比差异有显著性（ Ｐ＜ ０．０１）。

大黄素影响巨噬细胞升高[Ca^(2+)]_i和释放TNF-a的作用特征

为了研究大黄素(emodin)对正常的和细菌脂多糖(LPS)刺激的大鼠腹腔巨噬细胞(PM准)释放肿瘤坏死因子琢(TNF-琢)和升高[Ca2+]i的影响,应用L929细胞系和MTT法检测TNF-琢量,同时用激光共焦扫描显微术检测单细胞[Ca2+]i变化动力学。结果显示大黄素能轻度促进正常PM准释放TNF-琢,并发现大黄素诱发PM准[Ca2+]i变化呈振荡波模式。大黄素显著抑制LPS刺激PM准过度释放TNF-琢和升高[Ca2+]i,10-5mol/L大黄素抑制了10mg/LLPS刺激的TNF-琢峰值的50%和[Ca2+]i峰值的68%。LPS诱发PM准[Ca2+]i变化呈现高幅值的“平台期”,大黄素使之转变为低幅值的波动变化。以上结果说明,大黄素对PM准释放TNF-琢和升高[Ca2+]i表现出的双向调节作用之间有一定的相关性,大黄素对LPS诱发的[Ca2+]i升高的调制,可能是抑制LPS刺激PM准释放TNF-琢的信号传导通路中的重要环节。

银杏叶提取物在大鼠脑缺血再灌注损伤中的保护作用

目的:研究银杏叶提取物(GbE)对大鼠脑缺血再灌注损伤皮质内自由基、氨基酸动态平衡的影响及其对原代培养的大鼠海马神经元内游离钙离子浓度([Ca^(2+)]i)的影响和特征。方法:采用高压液相色谱仪测量大鼠大脑皮质中氨基酸(Glu、Asp、GABA、Gly)的浓度;MDA和GSH-Px采用TBA法测量,SOD采用嘌呤法测量。使用显微荧光检测系统检测单个原代培养的海马神经元内游离钙离子浓度([Ca^(2+)]i)的变化和特征。结果:与非治疗组比较,GbE各浓度治疗组的缺血大脑皮质内Glu、Asp和MDA含量在各时间观察点(缺血3h、缺血再灌注1h和缺血再灌注2h)均明显降低(P<0.01或P<0.05),而SOD和GSH-Px含量则在各时间观察点均明显升高(P<0.01或P<0.05);GbE 10mg/kg、15mg/kg治疗组缺血大脑皮质内的GA-BA和Gly含量在各时间观察点均有所降低(P<0.05)。与GbE 5mg/kg治疗组比较,GbE 10mg/kg、15mg/kg治疗组大脑皮质内的Glu、Asp和MDA含量在各时间观察点较低(P<0.05),而GABA、Gly、SOD和GSH-Px含量则较高(P<0.05);GbE 10mg/kg治疗组与15mg/kg治疗组之间差异无显著性。当向原代培养的神经元同时给予谷氨酸1×10^(-5)mol/L和GbE 25μg/ml 20s时所诱导的〔Ca^(2+)〕i明显低于单独使用谷氨酸1×10^(-5)mol/L所诱导的[Ca^(2+)]i变化,其峰值明显下降,且?