慢性低氧钙激活氯通道在大鼠肺动脉平滑肌细胞增殖中的作用

目的探讨慢性低氧时钙激活氯通道（ClCa）在大鼠肺动脉平滑肌细胞（PASMCs）增殖中的作用。方法将PASMCs分别置于常氧及慢性低氧下,采用形态学、流式细胞术、免疫细胞化学法,观察ClCa阻滞剂尼氟灭酸（NFA）和indaryloxyacetic acid（IAA-94）对PASMCs增殖的影响。结果慢性低氧：①PASMCs呈合成表型,而常氧为收缩表型,NFA和IAA-94干预后呈合成表型的PASMCs向收缩型转变;②S＋G2M期细胞所占比例增高,NFA和IAA-94干预后减低,且G0G1期细胞所占比例增加（P〈0.01）;③PCNA表达阳性率增高,NFA和IAA-94干预后降低（P〈0.01）;④c-fos和c-jun蛋白阳性染色A增高,NFA和IAA-94干预后降低（P〈0.01）。结论慢性低氧引起细胞表型改变,可促进细胞增殖,而抑制ClCa的活性可抑制细胞的增殖,提示ClCa参与了低氧PASMCs的增殖。     

SKF96365和氯化镍对环匹阿尼酸诱导的大鼠PASMC［Ca2＋］i升高的影响

目的：研究SKF96365和氯化镍（NiCl2）对环匹阿尼酸（CPA）诱导的大鼠远端肺动脉平滑肌细胞（PASMC）内游离钙离子浓度（[Ca2＋]i）变化的影响。方法培养大鼠PASMC,运用荧光显微镜和InCyte细胞内钙浓度检测系统观测CPA、SKF96365和NiCl2对PASMC[Ca2＋]i的影响。结果含5μmol／L硝苯地平的无钙Krebs溶液孵育PASMC,10μmol／LCPA使PASMC[Ca2＋]i短暂小幅升高,恢复细胞外Ca2＋至2．5mmol／L后,10μmol／LCPA使PASMC[Ca2＋]i迅速显著升高;50μmol／LSKF96365和500μmol／LNiCl2均能明显抑制10μmol／LCPA引起的PASMC[Ca2＋]i升高,但对高钾（60mmol／LKCl）溶液引起的PASMC[Ca2＋]i升高无影响。结论CPA可致大鼠PASMC[Ca2＋]i升高,且能被SKF96365和NiCl2阻断,提示CPA可能诱发细胞外Ca2＋经钙池操纵性钙通道（SOCC）内流,SKF96365和NiCl2能选择性抑制SOCC活性使经SOCC的Ca2＋内流减少。     

WIN 55,212-2对培养的大鼠三叉神经节神经元胞内游离钙离子浓度的影响

目的检测WIN55，212—2对培养的大鼠三叉神经节神经元细胞内钙离子浓度（[Ca^2＋]i）的影响并探讨其机制。方法以Fura一2／AM为钙探针，用细胞内双波长钙荧光系统检测细胞[Ca^2＋]i的变化。结果WIN55，2122（0．01～10μmol／L）可浓度依赖性地升高三叉神经节神经元细胞内[Ca^2＋]i，EC50为0．47μmol／L；用大麻素Ⅰ型受体（CBI受体）阻断剂AM251孵育后，发现10μmol／L的AM251可明显抑制10μmol／L WIN55。212—2对三叉神经节神经元细胞内[Ca^2＋]i的作用（P〈0．01）。结论WIN55，212—2可浓度依赖性地升高三叉神经节神经元细胞内[Ca^2＋]i，该作用可能是由CBI受体所介导。     

钙敏感受体在缺氧肺动脉平滑肌细胞中的表达及意义

目的观察肺动脉平滑肌细胞缺氧时钙敏感受体（calcium sensing receptor,CaSR）的表达,探讨其与缺氧性肺动脉平滑肌细胞增殖的关系。方法Ⅱ型胶原酶消化法提取、培养大鼠肺动脉平滑肌细胞。应用western blot技术分析CaSR、cyclinD1蛋白在肺动脉平滑肌的表达;采用激光共聚焦扫描显微镜观察不同干预情况下细胞内钙离子浓度（[Ca2＋]i）的变化,应用BrdU掺入方法分析不同处理因素对细胞DNA合成的影响。结果 CaSR蛋白在肺动脉平滑肌细胞有表达。缺氧能够增加CaSR、cyclinD1的表达、BrdU掺入率及[Ca2＋]i（与对照组比较,P〈0.05）。GdCl3（CaSR激动剂）能够增强缺氧的上述作用,NPS2390（CaSR抑制剂）则能够减弱缺氧的作用。结论缺氧诱导的CaSR表达增加参与了缺氧性肺动脉平滑肌细胞增殖。     

神经肽Y诱导大鼠心肌细胞肥大的钙信号机制

目的 探讨钙依赖的信号途径在神经肽Y（NPY）诱导心肌肥大中的作用。方法 NPY刺激乳鼠心肌细胞，加入钙调神经磷酸酶（CaN）抑制剂环胞素A（CsA）进行干预（5μg／mL），观察心肌细胞蛋白合成速率（^3H-Leu掺入量）、早期肥大反应基因（c-jun mRNA）表达以及胞浆和核内[Ca^2＋]i的变化。结果 经100nmol／L NPY刺激24h后，心肌细胞^3H-Leu掺入量、c-jun mRNA表达以及胞浆和核内[Ca^2＋]i均明显高于不加药对照组（P〈0．05，P〈0．01）；而CsA干预后的心肌细胞^3H-Leu掺入量和c-jun mRNA表达与对照组比较则无显著差别。结论 Ca^2＋／CaM依赖的CaN信号途径在NPY诱导心肌细胞肥大中起重要作用；NPY刺激细胞内[Ca^2＋]i增加，可能是活化CaN信号途径的始动环节。     

蛋白激酶C调节的1,4,5-三磷酸肌醇受体磷酸化在胆囊收缩素介导的胃窦平滑肌细胞钙动员中的作用

目的研究八肽胆囊收缩素（CCK-8）对大鼠胃窦平滑肌细胞（SMC）胞内钙释放和胞外钙内流的作用及对其具体相关机制的探讨。方法（1）多导生理记录仪记录大鼠离体胃窦肌条在不同条件下的收缩活动;（2）免疫印迹法和免疫沉淀法检测胃窦SMC的三型1,4,5-三磷酸肌醇受体（InsP3113）及其磷酸化水平;（3）Fura-2／AM标记胃窦SMC,观察CCK-8S对胞内钙离子浓度（[Ca^2＋]i）的影响;（4）全细胞膜片钳检测胃窦SMC的L-型电压门控钙通道电流（ICa-L）的变化情况。结果（1）CCK-8S作用下胃窦肌条收缩幅值和频率改变明显[增长率分别为（62±13）％和（58±17）％,均P〈0．01],可被CCK-A受体拮抗剂和钙泵抑制剂所阻断;（2）蛋白激酶C（PKC）上调InsP3R3磷酸化水平,抑制CCK-8S介导的内钙释放;（3）CCK-8S引起的[Ca^2＋]i显著升高[从（69±7）mol／L升至（472±36）nmol／L,P〈0．01]分别可被CCK-A受体或胞内钙泵抑制剂和PKC激动剂所阻断;去除外钙或给予L-型钙通道阻滞剂时CCK-8S仍可引起[Ca^2＋]i升高;（4）CCK-8S显著增强胃窦SMC的IICa-t。[从（-56±7）pA升至（-89±6）pA,P〈0．01],可分别被ICa-L阻滞剂、胞内钙泵抑制剂和钙依赖性氯通道阻滞剂所阻断。结论CCK-8S引起的大鼠胃窦SMC的[Ca^2＋]i升高依赖于PKC介导的InsP3R3磷酸化作用调节下的细胞内钙离子释放。胞内钙释放可激活ICl-Ca,引起细胞膜去极化而活化ICa-L引起胞外钙内流,最终引起SMC收缩效应。     

尼莫地平对癫痫大鼠海马Ca^2＋浓度及Ca^2＋/钙调蛋白依赖性蛋白激酶K表达的影响

目的探讨尼莫地平（nimodipin，NIM）对戊四氮（pentylenetetrazol，PrZ）点燃癫痫大鼠空间学习记忆能力及海马细胞内游离Ca^2＋浓度（[Ca^2＋]）、Ca^2＋／钙调蛋白依赖性蛋白激酶Ⅱ。（calcium／calmodulin—dependent protein kinase Ⅱn，CaMKⅡα）蛋白表达的影响。方法将动物分为正常对照组、PTZ组和NIM＋PTZ组，采用P佗慢性点燃癫痫模型，应用Mor—ris水迷宫观察各组大鼠空间学习记忆能力，运用流式细胞仪检测海马细胞内[Ca^2＋]．变化，Western blot方法测定CaMKⅡα蛋白的表达。结果PTZ组大鼠空间学习记忆能力受损，其海马细胞内[Ca^2＋]．明显升高（P〈0．05），CaMKⅡα蛋白水平较正常对照组减少（P〈0．05）；与PrZ组比较，NIM＋PrZ组大鼠空间学习记忆能力好转，其海马细胞内[Ca^2＋]．下降（P〈0．05），CaMKⅡα蛋白水平升高（P〈0．05）。结论PTZ点燃癫痫大鼠海马存在钙超载及CaMKⅡα的表达异常，由此引起大鼠空间学习记忆能力受损；NIM可以降低细胞内[Ca^2＋]．，提高CaMKⅡα的表达，改善癫痫大鼠的学习记忆能力。     

异丙酚麻醉下烧伤手术患者血小板聚集功能的变化

目的观察异丙酚静脉麻醉对大面积烧伤手术患者血小板聚集功能的影响.方法 55例大面积烧伤手术患者随机分为异丙酚组（P组）和氯胺酮组（K组）,分别于麻醉诱导前、手术开始30min、1、2h以及手术结束停药后1h采血,比浊法测量血小板最大聚集率,双波长荧光比值法测量血小板内游离Ca2＋浓度（[Ca^2＋]i）.结果 （1）两组烧伤患者的血小板最大聚集率、血小板静息[Ca2＋]i均明显高于正常对照组（C组）.与C组相比,P组和K组的血液明显处于高凝状态.（2）与术前相比,P组术中及术后血小板最大聚集率、血小板静息[Ca^2＋]i显著降低.（3）与术前相比,K组术中及术后血小板最大聚集率、血小板静息[Ca^2＋]i均进一步升高,明显高于诱导前.结论 （1）烧伤后血小板被激活,血小板内游离钙浓度（[Ca2＋]i）和聚集性均升高,血液处于高凝状态;（2）异丙酚通过降低血小板内游离钙水平,抑制血小板聚集作用,可稳定凝血功能状态.     

ADP和CPA诱导的高血压病人血小板胞浆游离钙的变化

[目的]探讨高血压病人血小板胞浆游离钙浓度(cytoplasmicfreeCa2 concentration,[Ca2 ]i)的变化.[方法]采用Fura-2/Am荧光双波长测定[Ca2 ]i技术,动态观察激动剂二磷酸腺苷(adenosinediphosphate,ADP)和环匹阿尼酸(cyclopiazonicacid,CPA)对高血压病人血小板[Ca2 ]i的影响.[结果]高血压病人静息血小板[Ca2 ]i与正常人比较明显增高(P<0.05);ADP和CPA激动的高血压病人的血小板平台钙与静息钙比较有统计学意义(P<0.05);峰位钙-平台钙的差(既钙释放)与正常人比较明显增高(P分别<0.05和<0.01);平台钙-静息钙的差(既钙内流)与正常人比较无明显差异(P>0.05).[结论]高血压病人静息血小板[Ca2 ]i增高,平台钙水平明显增高,血小板呈高反应状态;高血压病人的血小板被ADP和CPA激活不能恢复至静息动状态;ADP和CPA激动的高血压病人的血小板钙释放增多,钙内流正常.     

颅通定对猪肺动脉平滑肌细胞胞浆游离钙浓度的影响

采用钙荧光探针Fura－2／AM观察了颅通定对培养的猪肺动脉平滑肌细胞胞浆游离钙浓度（[Ca2＋]i）的影响。结果发现：颅通定可显著抑制高钾和BayK8644所致的[Ca＋]i增加，并且有剂量一效应关系，对静息状态[Ca2＋]i无明显影响，其作用与维拉帕米相似，但较弱。提示：颅通定降低平滑肌细胞[Ca2＋]i的作用与其抑制电压依赖性钙通道有关，此为其降压作用机制之一。     

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

Hypoxic pul monary hypertension ( HPH) ischaracterized by an elevation of pul monary vascularreaction and pul monary vascular reconstruction.Cytoplasmic free Ca2 concentration ([ Ca2 ]i)plays a key role in the regulation of vascular tone ,pul monary vasoconstriction and proliferation ofsmooth muscle cells[1]. The present study evalua-ted the role of [Ca2 ]iin the regulation of pul mo-nary vascular tone through regulation of calcium-activated chloride (Clca) channels in rats under a-cute h…     

Effects of calcium-activated chloride channels on proliferation of pulmonary artery smooth muscle cells in rats under chronic hypoxic condition

Objective: To investigate the effects of calcium-activated chloride (C1Ca) channels on proliferation of pulmonary artery smooth muscle cells(PASMCs) in rats under chronic hypoxic condition. Methods:The cultured PASMCs were placed under normoxic and chronic hypoxic conditions:The cells were observed by light and electron microscope; The cell cycles were observed by flow-cytometry; Immunocytochemistry staining was used to detect the expressions of PCNA, c-los and c-jun of PASMCs; Cytoplasmic free Ca2 con-centration ([Ca2 ]) in PASMCs was investigated by fluorescent quantitation using fluorospectrophotometer. Results:The PASMCs were contractile phenotype under normoxic conditions. Observation by transmission electron microscope: In kytoplasm of contractile phenotype cells, myofilament bundles were abundant and the content of cell organs such as Golgi's bodies were rare. The PASMCs were synthetic phenotype under chronic hypoxic condition. There were inereased free ribosomes, dilated rough endoplasmic reticulums, highly developed Golgi complexes, decreased or disappeared thick filaments and dense body in kytoplasm of synthetic phenotype cells. After NFA and IAA-94, the situations were reversed The number of S4,GzM PASMCs were significantly increased in chronic hypoxic condition; The NFA and IAA-94 were shown to significantly decrease them from (28.6±1.0)% to (16.0±1.6)% and the number of G0G1 PASMCs significantly increased from (71.4 ±1.9)% to (83.9±1.6)% (P＜ 0.01). In chronic hypoxic conditions, the expression of proliferating cell nucleus antigen was significantly increased; The NFA and IAA-94 were shown to significantly decrease it from (81±6)% to (27±7)%(P＜0.01). The expression of c-los and c-jun were significantly increased in-chronic hypoxic conditions; The NFA and IAA-94 were shown to significantly decrease them from 0.15 ± 0.02, 0.32 ± 0.05 to 0.05 ± 0.01, 0.12±0.05, respectively (P＜ 0.01); Under chronic hypoxic conditions, [Ca2 ]. Was increased; The NFA and IAA-94 decreased it from (281.8±16.5)nmol/L to (117.7±15.4)nmol/L(P＜0.01). Conclusion:Hypoxia initiated the change of PASMCs from contractile to synthetic phenotype and increased proliferation of PASMCs. NFA and IAA-94 depressed cell proliferation by blocking C1Ca channels in hypoxic condition. These may play an important role in proliferation of PASMCs under chronic hypoxic conditions.     

Relationship of intracellular free Ca2+ concentration and calcium-activated chloride channels of pulmonary artery smooth muscle cells in rats under hypoxic conditions

Summary To investigate the relationship between intracellular free Ca²⁺ concentration ([Ca²⁺]_i) and calcium-activated chloride (Cl_CB) 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 perfusionin vitro. The fluorescence Ca²⁺ indicator Fura-2/AM was used to observe [Ca²⁺]_i of rat PASMCs under normal and chronic hypoxic condition. The effect of Cl_CB channels on PASMCs proliferation was assessed by MTT assay. The Cl_CB 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, [Ca²⁺]_i was increased. Under normoxic condition, [Ca²⁺]_i was (123.63±18.98) nmol/L, and in hypoxic condition, [Ca²⁺]_i was (281.75±16.48) nmol/L (P<0.01). Under normoxic condition, [Ca²⁺]_i showed no significant change and no effect on Cl_CB channels was observed (P>0.05 Chronic hypoxia increased [Ca²⁺]_i which opened Cl_CB channels. The NFA and IAA-94 blocked the channels and decreased [Ca²⁺]_i from (281.75±16.48) nmol/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 [Ca²⁺]_i which opened Cl_CB channels and had a positive-feedback in [Ca²⁺]_i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Cl_CB channel may play a part in the regulation of proliferation of PASMCs. YANG Zhao, female, born in 1967, Doctor in Charge     

心脉隆对肺动脉平滑肌细胞缺氧损伤的保护作用

目的:研究心脉隆(XML)注射液对人源性肺动脉平滑肌细胞(PASMCs)缺氧损伤的保护作用,探讨XML降低肺动脉高压(PAH)的可能机制?方法:利用Na2S2O4建立缺氧模拟肺动脉高压细胞缺氧模型,流式细胞术观察缺氧刺激下细胞凋亡率,实时定量PCR检测凋亡相关基因表达,采用激光共聚焦法检测细胞膜电位?胞浆钙离子的表达变化?结果:在缺氧情况下,与对照组比较,PASMCs 增殖显著,Bcl-2基因表达增高,Bax表达下调,具有显著性差异(P < 0.05)?而XML能显著抑制缺氧过程中Bcl-2基因表达上调及Bax基因表达的下调,差异具有统计学意义(P < 0.05)?此外,XML能稳定细胞膜电位和降低胞浆钙浓度,抑制缺氧诱导的PASMCs增殖?结论:XML可减轻因缺氧引发的PASMCs凋亡减少而导致的平滑肌增殖重塑,为XML用于临床肺动脉高压的治疗提供实验依据?     

内源性NO对低氧下大鼠肺动脉平滑肌细胞增殖的影响

目的 探讨内源性一氧化氮(NO)对低氧下离体肺动脉平滑肌细胞( PASMCs)增殖的影响.方法 原代培养Wistar大鼠PASMCs,分常氧组(21％O2,5％CO2)和低氧组(1％ O2,94％N2,5％ CO2)进行培养,分别应用非选择性一氧化氮合酶抑制剂NG-硝基-L-精氨酸甲酯(L-NG-nitro-arginine methyl ester,L- NAME)进行干预,用细胞计数和四甲基偶氮唑蓝比色法(MTT)检测细胞增殖水平.结果 低氧下的肺动脉平滑肌细胞2天后明显增殖,与常氧组相比有显著性差异(P＜0.01),5天后细胞数达到峰值.L - NAME低氧干预组细胞增殖水平明显高于低氧组和常氧组(P＜0.01).结论 L-NAME抑制内源性NO的产生进而促进低氧诱导的肺动脉平滑肌细胞增殖.     

Effects of 3, 4-Dihydroxyacetophenone on Cytosolic Calcium in Pulmonary Artery Endothelial and Smooth Muscle Cells during Acute Hypoxia

Summary: The effects of 3, 4-Dihydroxyacetophenone (3. 4-DHAP) on cytosolic free calcium[Ca^2 ], in pulmonary artery endothelia (PAECs) and smooth muscle cells (PASMCs) during acute hypoxia were studied. Porcine pulmonary artery endothelial and smooth muscle cells (PASMCs)were cultured primarily, and they were divided into 4 groups: groups incubated under normoxia or hypoxia and those with or without treatment with 3. 4-DHAP. The [Ca^2 ]i of both PAECs and PASMCs was measured by determining the fluorescence of fura 2 AM on spetrofluorometer. Our results showed that hypoxia caused significant elevation of [Ca^2 ]i. in both PAECs and PASMCs,3, 4-DHAP could attenuate the hypoxic elevation of [Ca^2 ]i only in PASMCs but not in PAECs. It is concluded that 3, 4-DHAP decreases the hypoxic elevation of [Ca^2 ]i in PASMCs. This might contribute to its inhibitory effect on hypoxic pulmonary vasoconstriction.     

Functional Characteristics and Molecular Identification of Swelling-activated Chloride Conductance in Adult Rabbit Heart Ventricles

Outwardly rectifying swelling-activated chloride conductance （ICl, Swell） in rabbit heart plays a critical role in cardioprotection following ischemic preconditioning （IP）. But the functional characterization and molecular basis of this chloride conductance in rabbit heart ventricular myocytes is not clear. Candidate chloride channel clones （e.g. ClC-2, ClC-3, ClC-4 and ClC-5） were determined using RT-PCR and Western blot analysis.Whole cell ICl,Swell was recorded from isolated rabbit ventricular myocytes using patch clamp techniques during hypo-osmotic stress. The inhibitory effects of 4,4＇ isothiocyanato-2,2-disulfonic acid （DIDS）, 5-nitro-2（3-phenylroylamino） benzoic acid （NPPB） and indanyloxyacetic acid 94 （LAA-94） on ICl,Swell were examined. The expected size of PCR products for ClC-2, ClC-3 and ClC-4 but not for ClC-5 was obtained. ClC-2 and ClC-3 expression was confirmed by automated fluorescent DNA sequencing. RT-PCR and Western blot showed that ClC-4 was expressed in abundance and ClC-2 was expressed at somewhat lower levels. The biological and pharmacological properties of ICl,Swell, including outward rectification, activation due to cell volume change, sensitivity to DIDS, LAA-94 and NPPB were identical to those known properties of ICl,Swell in exogenously expressed systems and other mammals hearts. It was concluded that ClC-3 or ClC-4 might be responsible for the outwardly rectifying part of ICl,Wwell and may be the molecular targets of cardioprotection associated with ischemic preconditioning or hypo-osmotic shock.