低渗对比剂剂量对犬肾小管上皮细胞凋亡的作用及对其中Caspase-3表达的影响

目的：研究低渗碘对比剂剂量对犬肾小管上皮细胞凋亡的作用及对其中Caspase-3表达的影响,以期为临床使用低剂量低渗对比剂以降低副反应提供实验依据。材料与方法：家犬静脉高压注射（1.0 mL/s）高、低剂量（分别换算成相当于人用剂量1.5 mL/kg、1.0 mL/kg）碘普罗胺300 mgI/mL,对照组分别给予等剂量生理盐水,注射后48 h取犬肾脏,TUNEL染色检测肾小管上皮细胞的凋亡情况,免疫组化方法观察其中Caspase-3的表达。Western方法半定量检测肾脏髓质中Caspase-3的表达。结果：注射对比剂后肾小管上皮细胞凋亡率及Caspase-3表达较对照组均明显增高（P<0.01）,且对比剂高剂量组较低剂量组增高更明显（P<0.01）。结论：临床常用低渗对比剂常规剂量亦能引起犬肾小管上皮细胞凋亡,且与剂量有关,低剂量对比剂可能降低对比剂副反应的发生,Caspase-3可能参与了对比剂诱导肾小管上皮细胞凋亡的调控。     

姜黄素预防造影剂对大鼠肾小管上皮细胞的损伤

目的:探讨姜黄素对优维显370诱导的大鼠造影剂肾病(CIN)的预防作用。方法:雌性SD大鼠随机分为正常对照组(C)、造影剂肾病组(CIN)和姜黄素防治组(CUR),每组各5只。分别每隔15 min尾静脉注射吲哚美辛、L-NAME和优维显370(8 mL/kg)建立大鼠CIN模型。姜黄素在注射优维显370前5 d开始灌胃。所有大鼠均在注射造影剂后24h杀检。用TUNEL检测肾小管上皮细胞凋亡,硫代巴比妥酸法(TBA)测定肾脏丙二醛(MDA)水平。结果:姜黄素预防治疗显著降低造影剂肾病大鼠肾小管上皮细胞坏死指数、肾小管上皮细胞凋亡率、肾髓质淤血程度、肾脏MDA水平、血肌酐和肾重指数(均P<0.05)。结论:姜黄素可通过抗氧化活性而预防造影剂对大鼠肾小管上皮细胞损伤,从而预防CIN发病。     

钙离子拮抗剂对大鼠心肌梗死后心肌细胞凋亡的影响

目的探索钙离子拮抗剂对缺血后心肌细胞凋亡的影响.方法结扎大鼠冠状动脉(冠脉)造成心肌梗死;实验组动物冠脉结扎前和术后3 h分别经口腔内滴注和腹腔注射钙离子拮抗剂Adalat 1 mg/kg和0.4 mg/kg,缺血对照组给安慰剂;正常对照组行假手术不结扎冠脉,给安慰剂.术后6 h测定左室功能,并取心脏标本作原位缺口末端标记法(TUNEL)原位细胞凋亡和Fas、Bcl-2蛋白免疫组织化学(组化)染色,高倍镜下计算细胞凋亡指数.结果实验组和缺血对照组的左室收缩压、左室舒张末压和压力改变速度(dp/dt)无显著差异,3个指标分别为76.7±7.5/8.0±6.1 mm Hg比74.9±11.1/11.6±8.3 mm Hg,P>0.05;(777.3±128.6)mm Hg/s比(761.8±136.4)mm Hg/s,P>0.05;但均低于正常对照组[94.9±7.5/2.8±3.2 mm Hg,P<0.001;(1 131.5±112.8)mm Hg/s,P<0.001];实验组和缺血对照组心肌缺血区TUNEL染色阳性,实验组心肌细胞凋亡指数显著低于缺血对照组(0.201±0.053比0.261±0.045,P<0.05),在缺血周边的心肌区Fas和Bcl-2蛋白免疫组化染色阳性,而正常对照组3种染色均阴性.结论缺血可诱导心肌细胞凋亡及Fas和Bcl-2基因的表达;钙离子拮抗剂具有抑制心肌细胞凋亡的作用.     

低频超声联合微泡造影剂诱导人胆囊癌GBC-SD细胞凋亡的实验研究

目的探讨低频超声联合微泡造影剂对人胆囊癌GBC-SD细胞凋亡的影响。 方法将培养的人胆囊癌GBC-SD细胞分为4组,每组设5个复孔。其中空白对照组不进行任何处理;微泡组加200 μl的微泡造影剂混匀,使微泡浓度为20%,不进行超声辐照;低频超声组以超声辐照声强为0.45 W/cm²、超声脉冲波频率为1 MHz的低频超声连续波辐照,连续辐照30 s,不加造影剂;联合组加入200 μl的微泡造影剂,混匀后以1 MHz低频超声,连续波辐照30 s。各组以CCK-8法检测细胞增殖活性,并用流式细胞仪测定各组细胞的凋亡情况。 结果空白对照组、微泡组、低频超声组、联合组GBC-SD细胞增殖活性分别为0.9272±0.1173、1.0088±0.0628、0.2116±0.0101、0.1470±0.0029。联合组细胞增殖活性低于空白对照组、微泡组、低频超声组,差异均有统计学意义（t=14.846、30.637、13.661,P均<0.05）。各处理组间细胞凋亡率差异有统计学差异（F=2390.900,P<0.05）,联合组细胞凋亡率为0.682±0.022,显著高于空白对照组的0.073±0.005、微泡组的0.031±0.003、低频超声组的0.259±0.012,差异均有统计学意义（P均<0.05）。 结论低频超声联合微泡造影剂能降低体外培养的人胆囊癌GBC-SD细胞增殖活性,明显诱导人胆囊癌GBC-SD细胞凋亡。     

非选择性环氧化酶抑制剂诱导结肠癌细胞凋亡的研究

目的：研究非选择性环氧化酶抑制剂舒林酸对结肠癌细胞株HT-29生长的影响及其参与引起细胞凋亡的可能机制。方法：采用四甲基偶氮唑蓝比色法检测舒林酸对结肠癌细胞增殖的抑制作用,采用激光共聚焦显微镜（LSM）观察细胞凋亡情况,采用流式细胞仪（FCM）分析其对细胞凋亡及细胞周期的影响。结果：舒林酸能呈剂量和浓度依赖性押制HT-29的增殖．在4．8mmol·L^-1时其抑制率可迭91．8％。AnnexinV／H染色后LSM观察到凋亡细胞胞膜绿染,胞核红染或呈桔黄色。FCM显示此药能促进细胞的凋亡,使处于G0／G1期的细胞比例显著降低。结论：舒林酸可抑制结肠癌细胞株HT-29生长,其机制可能与其阻止细胞周期的进展,诱导细胞凋亡有关。     

载紫杉醇超声微泡造影剂对人肝癌细胞株HepG2增殖影响及诱导凋亡作用研究

目的 探讨超声辐照紫杉醇微泡造影剂对人肝癌细胞株HepG2增殖抑制的影响和诱导凋亡作用.方法 体外培养肝癌细胞,将细胞分4组,即空白对照组,紫杉醇组,超声空白微泡组,超声载紫杉醇微泡组.MTT法观察不同处理组不同时间点对细胞生长的影响,Annexin V-FITC荧光染色检测其对诱导细胞凋亡作用.结果 超声载紫杉醇微泡组对细胞的增殖抑制作用强于其他处理组及对照组;超声载紫杉醇微泡组能够诱导肿瘤细胞发生凋亡.结论 超声辐照紫杉醇微泡造影剂对人肝癌细胞株HepG2生长有明显抑制作用,并诱导细胞凋亡.     

缺氧诱导离体心肌细胞凋亡的动物实验研究

目的：建立一种新的SD乳鼠心肌细胞的缺氧模型,以探讨心肌细胞缺氧损伤后的细胞凋亡及其时序分布特点。方法：SD乳鼠的培养心肌细胞随机分为5组：对照组,缺氧12h组(112h)、缺氧24h组(14h),缺氧48h组(148h)以及缺氧72h组(172h)。应用流式细胞术、DNA琼脂糖凝胶电泳、透射电镜等多种手段检测心肌细胞凋亡的改变。结果：在本实验的心肌细胞缺氧模型中,流式细胞仪检测发现,心肌细胞缺氧后的细胞凋亡百分率迅速增高。琼脂糖凝胶电泳分析。心肌细胞在缺氧48h、72h时均出现了凋亡特异性的“梯状”电泳带。结论：本实验培养乳鼠心肌细胞缺氧模型可导致心肌细胞凋亡,凋亡程度和心肌细胞缺氧时间有关,并可导致和在体心肌缺血相似的心肌损伤。细胞凋亡在心肌缺氧心肌细胞死亡中起重要作用。     

蛋白酶体抑制剂MG-132诱导L1210细胞凋亡及其机制研究

为了观察蛋白酶体抑制剂MG-132对淋巴细胞白血病细胞株L1210的致凋亡作用,探讨MG-132的致凋亡机制,分别以不同浓度的蛋白酶体抑制剂MG-132处理L1210细胞,用四甲基偶氮唑蓝(MTT)法检测细胞活力,应用Annexin-Ⅴ和PI双染色细胞流式细胞术检测细胞凋亡率,比色法测定细胞中caspase3的活性,采用Western-blot法检测细胞NF-κB P65核蛋白的表达。结果表明:在相同的作用时间下,随着MG-132浓度的增高(0、2.5、5、10、20μmol/L),细胞增殖抑制率、凋亡率、caspase3活性逐渐升高;Western-blot法检测显示,细胞NF-κB P65核蛋白表达水平降低。结论:蛋白酶体抑制剂能够诱导L1210细胞凋亡,其机制可能是通过下调NF-κB的表达,进一步活化caspase3的活性而诱导凋亡。     

caspase抑制剂对缺氧诱导的心肌细胞凋亡影响的实验研究

目的 探讨caspase抑制剂对缺氧诱导的培养乳鼠心肌细胞凋亡的作用。方法 将SD乳鼠的培养心肌细胞随机分为3组:对照组、缺氧72 h(I72 h)组,以及caspasee抑制剂组。应用TUNEL法及流式细胞仪分析心肌细胞凋亡的变化;借助caspase-3荧光分析试剂盒,荧光比色法检测心肌细胞凋亡过程中caspase-3活性的变化。结果 caspase抑制剂组凋亡指数(AI值)和细胞凋亡百分率分别为:(14.10±2.56)％,(14.93±2.47)％,与I72 h组(46.49±4.93)％、(48.43±4.18)％相比明显降低(P<0.01)。caspase-3活性检测显示:caspase抑制剂组的caspase-3活性比缺氧72 h组降低了52.85％(P<0.01)。结论caspase抑制剂能明显抑制缺氧诱导的心肌细胞凋亡,其作用机制与抑制caspase-3蛋白酶活性密切相关。     

超声造影剂对血管平滑肌细胞增殖、迁移和凋亡的影响

目的探讨超声波联合超声造影剂对平滑肌细胞增殖、迁移和凋亡的影响.方法体外培养大鼠胸主动脉血管平滑肌细胞（VSMC）.采用MIT法、Millicell小室、Annexin V-FITC/PI双标染色和流式细胞仪,检测VSMC的增殖、迁移能力和凋亡,观察血小板衍生生长因子--BB（PDGF-BB）对VSMC增殖、迁移和凋亡的影响,频率1 MHz、声强0.3 W/cm^2的连续波超声联合声学造影剂辐照VSMC后上述指标的变化.结果PDGF-BB对VSMC的凋亡无影响,但可促进VSMC增殖和迁移.超声联合造影剂辐照VSMC 30 s即可显著抑制PDGF-BB所致的VSMC增殖（P〈0.05）,同时细胞凋亡比例显著增高（P〈0.01）,辐照60 s可显著抑制PDGF-BB所致的VSMC迁移（P〈0.05）,随着辐照时间延长,以上作用增强,辐照60 s时对VSMC增殖的抑制程度最强.结论低强度超声波辐照联合超声造影剂可抑制VSMC增殖、迁移,并促进细胞凋亡.     

Overexpression of the Na+/Ca2+ exchanger influences ouabain‐mediated spontaneous Ca2+ activity but not positive inotropy

Administration of digitalis in heart failure (HF) increases quality of life but does not carry a prognostic benefit. Digitalis is an indirect inhibitor of the Na⁺/Ca²⁺ exchanger (NCX), which is overexpressed in HF. We therefore used the cardiac glycoside ouabain in Ca²⁺ imaging experiments and patch‐clamp experiments in isolated ventricular myocytes from nonfailing transgenic NCX overexpressor mice (OE). In field‐stimulated myocytes, ouabain (1–100 μm ) increased the amplitude of the Ca²⁺ transient in OE and wild‐type (WT) similarly. Ouabain‐mediated spontaneous Ca²⁺‐activity was significantly more pronounced in OE compared to WT myocytes at higher concentrations (100 μm). Also, at very high concentrations (1000 μm ) of ouabain, the number of cells with hypercontraction leading to cell death was higher in OE. Ouabain (10 μm ) shortened the action potential duration in both genotypes. Our findings suggest that the proarrhythmic but not the inotropic effects of cardiac glycosides are enhanced by increased NCX expression. This may offer an explanation for the observed lack of prognostic benefit but increased quality of life in HF, which is accompanied by NCX upregulation.     

Na+/Ca2+‐exchanger‐mediated Mn2+‐enhanced 1H2O MRI in hypoxic,perfused rat myocardium

Paramagnetic Mn²⁺ has emerged in the search for non‐invasive magnetic resonance imaging (MRI) techniques to monitor Ca²⁺ in diagnostic and prognostic cardiovascular disease tests because it both alters MRI contrast and behaves as a Ca²⁺ ‘surrogate’ in vivo. However, the reliance on macroscopically averaged measurements to infer microscopic processes constitutes a major limitation of MRI. This investigation circumvents this limitation and contributes an MRI‐based myocardial Ca²⁺‐transporter assay, which probes the Na⁺/Ca²⁺‐exchanger involvement in Mn²⁺ (and presumably Ca²⁺) transport by virtue of its response to pharmacological inhibition. In the model employed herein, ex vivo arrested rat hearts underwent normoxia and then hypoxia while a constant (hyperkalemic) perfusion minimized flow (and uncontrolled Ca²⁺‐channel) contributions to Mn²⁺‐enhanced MRI measurements. The results (i) demonstrate that Mn²⁺ (and presumably Ca²⁺) accumulates via Na⁺/Ca²⁺‐exchanger‐mediated transport during hyperkalemic hypoxia and further, (ii) implicate hypo‐perfusion (rather than the diminished participation of an isolated sarcolemmal Ca²⁺‐transporter) as the mechanism that underlies the reported reductions of Mn²⁺ accumulation (relative to healthy myocardium) subsequent to myocardial insults in MRI studies. Although myriad studies have employed Mn²⁺‐enhanced MRI in myocardial investigations, this appears to be the first attempt to assay the Na⁺/Ca²⁺‐exchanger with MRI under highly circumscribed conditions. MRI‐based Ca²⁺‐transporter assays, such as the Na⁺/Ca²⁺‐exchanger assay utilized here, will inevitably impact disciplines in the medical sciences and beyond. Copyright © 2007 John Wiley & Sons, Ltd.     

Effect of Na+ reduction and monensin on ion content and contractile response in normoxic and ischaemic reperfused rat hearts

Summary— The possibility was explored whether the functional properties of Na+/Ca²⁺ exchange are altered after ischaemia, thereby contributing to the elevated intracellular (i) Ca²⁺ levels in ischaemic reperfused hearts. The intracellular Na+, K+ and Ca²⁺ contents in rat Langendorff heart preparations were determined by atomic absorption spectrometry under normoxic conditions, after ischaemia (30 min) and after ischaemia (30 min) plus reperfusion (30 min). In addition, the influence of modulating the Na+ gradient (Na+_o/Na+_i) across the sarcolemma was studied with respect to cardiac contractility and intracellular ion content. This was done by either decreasing extracellular (o) Na+ or by increasing Na+_i with monensin, both in normoxic and reperfused hearts. Both Na+_o reduction and monensin led to an increase in contractility and coronary flow, an effect which was nearly abolished in reperfused hearts. Under normoxic conditions the intracellular ion contents amounted to Na+ = 12.4 ± 0.4, K+ = 99.0 ± 3.1 and Ca²⁺ = 0.64 ± 0.02 mmol/kg cell (means ± SEM, n = 7). In normoxic hearts, lowering Na+_o reduced and monensin increased Na+_i, thereby both leading to a decrease in Na+ gradient; no effect on total Ca²⁺_i content was observed. Na+_i increased twofold after ischaemia as compared to the normoxic situation, an effect which was aggravated (4 fold increase) in reperfused hearts. The opposite effects were observed for K+_i with a 25% decrease after ischaemia and a 40% decrease in reperfused hearts. Only after ischaemia plus reperfusion was Ca²⁺_i increased (6 fold). In reperfused hearts, lowering Na+_o again reduced and monensin increased Na+_i, whereas a further rise in Ca²⁺_i was now observed depending on the Na+ gradient across the sarcolemma: the larger the drop in Na+ gradient, the more pronounced the increase in Ca²⁺_i in the reperfused heart. We conclude that the Ca²⁺_i increase in reperfused hearts can be modulated by changing the Na+ gradient across the sarcolemma. This suggests that inhibited or reversed Na+/Ca²⁺ exchange is predominantly responsible for the rise in Ca²⁺_i in ischaemic hearts that are subjected to reperfusion.     

Fas和FasL在Na+/H+交换器-1抑制诱导缺氧大鼠肺动脉平滑肌细胞凋亡中的作用

目的探讨Fas、FasL在Na^＋／H^＋交换器-1（NHE-1）抑制所诱导的缺氧大鼠肺动脉平滑叽细胞（PASMCs）凋亡中的作用。方法将转染NHE-1特异性核酶基因的大鼠PASMCs置于缺氧条件下（O2的体积分数低下1％）培养。缺氧培养2、6、12、24和48h后用原位末端标记法（TUNEL）检测细胞凋亡情况；半定量逆转录-聚合酶链反应（sqRT—PCR）疗法检测细胞内fas和fasL mRNA表达变化；免疫细胞化学法检测细胞内Fas和FasL蛋白表达变化。结果转染NHE-1特异性核酶基因的大鼠PASMCs在缺氧培养时，其细胞凋亡率随缺氧时间的延长而逐渐升高，但细胞内fas、fasL mRNA及Fas、FasL蛋白表达与对照组细胞比较差异均无显著性。结论Fas／FasL死亡通路可能不参与NHE-1抑制而诱导缺氧大鼠PASMCs凋亡的调控。     

Pre- or post-ischemic treatment with a novel Na+/Ca2+ exchange inhibitor, KB-R7943, shows renal protective effects in rats with ischemic acute renal failure

We investigated the effects of pre- or post-ischemic treatment with KB-R7943, a new Na+/Ca2+ exchange inhibitor, on ischemic acute renal failure (ARF) in rats, and these were compared with the effects of verapamil. Ischemic ARF was induced by clamping the left renal pedicle for 45-min followed by reperfusion, 2 weeks after contralateral nephrectomy. Renal function markedly decreased 24 h after reperfusion. Pre-ischemic treatment with KB-R7943 or verapamil attenuated the ARF-induced renal dysfunction. The ischemia/reperfusion-induced renal dysfunction was overcome by post-ischemic treatment with KB-R7943 but not with verapamil. Histopathological examination of the kidney of ARF rats revealed severe renal damage, and suppression of the damage was seen with post-ischemic treatment with KB-R7943. KB-R7943 markedly suppressed the increment of endothelin-1 (ET-1) content in the kidney at 2, 6, and 24 h after reperfusion. No significant changes in Na+/Ca2+ exchanger protein expression in renal tissue were observed with 45-min ischemia, 6 h after reperfusion and KB-R7943 treatment. These results suggest that Ca2+ overload via the reverse mode of Na+/Ca2+ exchange, followed by ET-1 overproduction, seems to play an important role in the pathogenesis of the ischemia/reperfusion-induced ARF. KB-R7943, which is effective in both cases of pre- and post-ischemic treatments, may prove to be an effective therapeutic agent for cases of ischemic ARF.     

bcl-2、bax在NHE-1核酶基因转染所致缺氧大鼠肺动脉平滑肌细胞凋亡中的作用

目的　探讨 bcl 2、bax表达在 Na / H 交换器 1(NHE 1)抑制而诱导缺氧大鼠肺动脉平滑肌细胞 (PASMCs)凋亡中的作用。方法　将转染 NHE 1特异性核酶基因大鼠的 PASMCs置于缺氧条件下(O2 的体积分数 <1% )培养 ,分别在缺氧 0、2、6、12、2 4和 4 8h采用原位细胞凋亡检测法观察细胞凋亡情况 ,荧光指示剂 Fura 2 / AM测定法检测细胞内 Ca2 浓度 (〔 Ca2 〕i)变化 ,半定量逆转录聚合酶链反应方法检测细胞内 bcl 2 m RNA和 bax m RNA表达变化 ,免疫组化法检测细胞内 Bcl 2蛋白和 Bax蛋白表达的变化。结果　转染 NHE 1特异性核酶基因大鼠的 PASMCs在缺氧培养时 ,其细胞凋亡率随缺氧时间的延长而逐渐升高 ,但是〔 Ca2 〕i升高的幅度较小 ,从缺氧 6 h起就显著低于同时间点的对照组和转染逆转录病毒真核表达载体空载体组 (P均 <0 .0 1) ,bcl 2 m RNA及蛋白表达显著降低 ,bax m RNA和蛋白表达显著增加(P均 <0 .0 1)。结论　 NHE 1抑制可能通过阻止 PASMCs的〔 Ca2 〕i增加 ,并引起 bcl 2表达降低及 bax表达增加而诱导和促进缺氧培养的 PASMCs凋亡     

中药补肾方对心力衰竭大鼠Na+-K+ATP酶、Ca2+-Mg2+ATP酶和琥珀酸脱氢酶的作用研究

目的研究补肾方对心力衰竭大鼠Na+-K+ATP酶、Ca2+-Mg2+ATP酶和琥珀酸脱氢酶(SDH)的作用。方法 60只大鼠随机分为模型组、假手术组、曲美他嗪组、补肾低、中、高剂量组,每组10只。采用结扎冠状动脉前降支法制备心力衰竭大鼠模型,术后2周开始灌胃,分别给予药物干预8周。8周后通过颈动脉插管记录大鼠血流动力学改变,包括左室收缩压(LVSP)、左室舒张压(LVEDP)、左室内压上升下降最大速率(±LVdp/dtmax);采用分光光度计检测心力衰竭大鼠心肌Na+-K+ATP酶、Ca2+-Mg2+ATP酶以及SDH水平。结果模型组大鼠心肌LVSP和+LVdp/dtmax较假手术组明显降低(P<0.01),而LVEDP和-LVdp/dtmax明显升高(P<0.05);补肾方干预后,中、高剂量大鼠心肌收缩、舒张功能明显优于模型组(P<0.01),以高剂量补肾方改善心力衰竭大鼠心功能明显。补肾方干预后,Na+-K+ATP酶、Ca2+-Mg2+ATP酶和SDH活力高于模型组,但低于假手术组,且随补肾方剂量增加,Na+-K+ATP酶、Ca2+-Mg2+ATP酶和SDH活力逐渐增强。结论补肾方可改善心力衰竭大鼠的心功能,可能与Na+-K+ATP酶、Ca2+-Mg2+ATP酶以及SDH活力增强相关。     

Monitoring the intracellular store Ca2+ concentration in agonist‐stimulated,intact human platelets by using Fluo‐5N

Summary. Background: Most Ca²⁺ signaling research in platelets has relied solely on monitoring the cytosolic Ca²⁺ concentration ([Ca²⁺]_cyt). Changes in [Ca²⁺]_cyt constitute the net effect of Ca²⁺ fluxes into the cytosol across the plasma membrane (PM) and from intracellular stores, and Ca²⁺ sequestration into the stores and Ca²⁺ removal across the PM. This makes interpretation of the effects of pharmacologic or genetic interventions on Ca²⁺ signaling difficult and subject to error. Objectives: To validate the use of the low‐affinity Ca²⁺ indicator Fluo‐5N to monitor the concentration of Ca²⁺ in the intracellular stores ([Ca²⁺]_st) of human platelets as a first step in developing assays for a systems‐level analysis of platelet Ca²⁺ signaling. Methods: Fluo‐5N‐loaded and Fura‐2‐loaded human platelets were used to observe the effects of agonist stimulation and other manipulations on [Ca²⁺]_cyt and [Ca²⁺]_st. Results: Fluo‐5N fluorescence changed appropriately in response to compounds that induce passive depletion of intracellular Ca²⁺ stores and to physiologic agonists. Ca²⁺ reuptake inhibitors and blockers of Ca²⁺ release channels had the expected effects on Fura‐2 and Fluo‐5N fluorescence. Agonist‐evoked Ca²⁺ release was reversed by Ca²⁺ addition to the medium, and required intact Ca²⁺ reuptake mechanisms. Store refilling was observed in the presence of sarcoplasmic/endoplasmic reticulum Ca²⁺‐ATPase (SERCA) inhibitors and ionomycin, suggesting the presence of a non‐SERCA Ca²⁺ reuptake mechanism. Evidence for a role for Ca²⁺‐induced Ca²⁺ release in agonist‐evoked responses was obtained. Conclusions: Our data provide a validation of the use of Fluo‐5N as a method for monitoring changes in [Ca²⁺]_st in human platelets.     

锤头状核酶抑制CTLL-2细胞凋亡而增强其对Yac-1细胞杀伤活性的实验研究

目的　研究抗fas的锤头状核酶对小鼠细胞毒性T淋巴细胞 (CTL)系CTLL 2细胞fas基因的表达及其介导的细胞凋亡抑制作用 ,探索供者淋巴细胞输注 (DLI)时增强T细胞抗白血病的新途径。方法设计并合成抗fas的锤头状核酶基因 ,将其导入CTLL 2细胞 ,通过RT PCR、Westernblot和流式细胞仪分别检测核酶对CTLL 2细胞fasmRNA和Fas蛋白表达的抑制 ,以MTT法检测CTLL 2细胞与Fas抗体结合后的增殖活性 ,以半胱天冬酶 3(caspase 3)活性检测试剂盒检测细胞caspase 3蛋白酶活性 ,以流式细胞仪检测细胞凋亡 ,以乳酸脱氢酶法检测CTLL 2细胞的体外杀伤活性。结果锤头状核酶基因导入CTLL 2细胞后 ,可使其表面的Fas表达降低达 5 0 % ,细胞经Fas抗体 (JO2 )处理后 ,与空白对照、转染空载体的细胞相比 ,转染核酶的细胞增殖活性增加了 1倍 ,caspase 3活性降低近 5 0 % ,而细胞的凋亡率显著降低 ,只有 37% ,且CTLL 2细胞的体外杀伤活性为对照组的 2倍。结论该核酶具有切割fas基因的良好活性 ,并可抑制Fas介导的CTLL 2细胞凋亡 ,增加该细胞存活率 ,从而增强对Yac 1细胞的杀伤活性。