共查询到19条相似文献,搜索用时 203 毫秒
1.
目的研究眼睛蛇毒心脏毒素(Cardiotoxin,CTX)对心肌细胞的形态、收缩幅度和细胞内钙离子([Ca2+]i)的作用。方法应用荧光计量法(以Fura-2/AM为荧光染料)及光学成像系统来测定单个心肌细胞[Ca2+]i和收缩幅度。结果0.001~1μmol/L的CTX使心肌细胞由杆状变成圆形,药物的作用从第1分钟时开始,到第20分钟时趋于稳定。在电刺激存在的情况下,1μmol/L的CTX最初导致电诱导的[Ca2+]i和收缩幅度瞬间增加,接下来[Ca2+]i时程延长,最终细胞对电刺激不敏感、突然收缩、[Ca2+]i持续增高。在缺乏电刺激的情况下,1μmol/L的CTX可诱导Ca2+震荡波、持续性[Ca2+]i增高,这种作用与40mmol/L的KC l和10mmol/L咖啡因所引起的[Ca2+]i瞬间增加不同。结论CTX作用初期使[Ca2+]i增高,使细胞[Ca2+]i超载,同时伴随细胞形状的改变。 相似文献
2.
目的 研究马尾松花粉多糖PPM60-A及其硫酸酯化物SPPM60-A对大鼠动脉平滑肌细胞 [Ca2+]i调控及增殖的影响。方法 常规水提醇沉法制备马尾松花粉多糖,Sephacryl S-400HR色谱分离得PPM60-A,氯磺酸-吡啶法得硫酸酯化物SPPM60-A,酯化度为1.28。酶解法分离制备大鼠动脉平滑肌细胞,测定酯化前后多糖对其胞内 [Ca2+]i和细胞增殖的影响。结果 PPM60-A和SPPM60-A均可以降低 [Ca2+]i,抑制高K+和去甲肾上腺素(NE)诱导的钙离子升高,降低高K+引起的钙离子水平上升,对NE诱导的血管主动脉平滑肌细胞增殖具有显著的抑制作用。PPM60-A作用效果好于SPPM60-A。结论 PPM60-A及SPPM60-A均能抑制细胞外Ca2+内流,抑制血管平滑肌细胞增殖。 相似文献
3.
运用Ca2+指示剂Fura-2作为细胞内钙离子的荧光探针,利用AR—CM—MIC阳离子测定系统,检测了分离的神经细胞内游离钙及其变化,并观测了DGAVP和Org2766对蛋白质合成抑制剂茴香霉素(ANI)引起细胞内钙离子浓度([Ca2+]i)变化的影响。结果表明茴香霉素可使[Ca2+]i显著升高,且有量效关系;DGAVP本身并不引起[Ca2+]i发生显著变化,但适当剂量的DGAVP可显著对抗一定剂量范围内ANI升高[Ca2+]i的作用,提示DGAVP对抗ANI的蛋白质合成抑制效应可能是通过拮抗ANI升高[Ca2+]i这一途径实现的,另一神经肽Org2766则可能不是通过这一机制发生作用。从细胞内Ca2+的角度看,这两种肽的作用机理显然是不同的。 相似文献
4.
间尼索地平对5-羟色胺诱导大鼠肺动脉平滑肌细胞增殖和迁移的影响及其机制 总被引:2,自引:1,他引:1
目的探讨间尼索地平(m-Nis)对5-羟色胺(5-HT)诱导的大鼠肺动脉平滑肌细胞(PASMCs)增殖和迁移的影响,并深入研究其作用机制。方法采用植块法培养大鼠PASMCs。实验分为6组:空白对照组、5-HT(1μmol·L-1)组,m-Nis(10-5、10-6、10-7、10-8mol.L-1)组。噻唑蓝(MTT)比色法、Transwell迁移小室法分别测定PASMCs的增殖和迁移,Western blot法检测大鼠PASMCs中增殖细胞核抗原(PCNA)的蛋白表达及细胞外信号调节激酶1和2(ERK1/2)的磷酸化水平,研究m-Nis对ERK1/2/MAPK信号通路的影响。结果不同浓度m-Nis明显抑制了5-HT诱导的大鼠PASMCs增殖(P<0.05或P<0.01)和迁移(P<0.01),并呈现一定的浓度依赖性;另外,Western blot结果显示m-Nis对5-HT诱导的大鼠PASMCs中PCNA的蛋白表达有不同程度的抑制作用(P<0.05或P<0.01),10-5,10-6,10-7mol.L-1m-Nis还明显抑制了5-HT诱导的大鼠PASMCs中ERK1/2磷酸化水平的升高,p-ERK1/2/ERK1/2比值均有不同程度地降低(P<0.05或P<0.01)。结论m-Nis对5-HT诱导的大鼠PASMCs增殖和迁移有明显的抑制作用,可能与其抑制PCNA蛋白表达及ERK1/2/MAPK信号通路有关。 相似文献
5.
阿米洛利对大鼠压力超负荷性心肌肥厚的抑制作用 总被引:1,自引:0,他引:1
目的 观察钠氢交换体(NHE)抑制剂阿米洛利(Ami)对压力超负荷左室肥厚(LVH)大鼠心功能、心肌细胞内游离钙浓度([Ca2+]i)及心肌细胞膜Na+ 、K+-ATP酶活性的影响。方法 ①同步记录离体工作心脏LVSP、LVEDP、±dp/dtmax及T值;②测定Fura-2/A负载后的单个心室肌细胞的[Ca2+]i;③光电比 相似文献
6.
The effect of 1-[β-[3-(4-methoxyphenyl)pro- poxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride (SKF 96365) on Ca2+ signaling in Madin Darby canine kidney (MDCK) cells was examined. SKF 96365 at 25–100 μM evoked a robust [Ca2+]i transient in a dose-dependent manner, measured by fura-2 fluorimetry. A concentration of 10 μM SKF 96365 did not have an
effect. The transient consisted of a slow rise, a gradual decay, and a sustained plateau in physiological Ca2+ medium. Removal of extracellular Ca2+ reduced the Ca2+ signals evoked by 50–100 μM SKF 96365 by nearly half in the area under the curve, suggesting that SKF 96365 induced intracellular
Ca2+ release and also extracellular Ca2+ influx. A concentration of 100 μM SKF 96365 caused significant Mn2+ quench of fura-2 fluorescence, which was partly inhibited by La3+ (1 mM) or Gd3+ (0.1 mM), indicating that the SKF 96365-induced Ca2+ influx had two components: one is sensitive to La3+ (1 mM) or Gd3+ (0.1 mM), the other is not. The internal Ca2+ source for the SKF 96365-induced [Ca2+]i transient was the endoplasmic reticulum Ca2+ store because, pretreatment with thapsigargin and cyclopiazonic acid, two inhibitors of the endoplasmic reticulum Ca2+ pump nearly abolished the SKF 96365-induced [Ca2+]i increase in Ca2+-free medium. In contrast, pretreatment with 100 μM SKF 96365 only partly depleted the thapsigargin-sensitive Ca2+ store. Addition of 10 mM Ca2+ induced a significant [Ca2+]i increase after prior incubation with 100 μM SKF 96365 in Ca2+-free medium, demonstrating that SKF 96365 induced capacitative Ca2+ entry. This capacitative Ca2+ entry was about 40% of that induced by 1 μM thapsigargin. Additional to inducing its own capacitative Ca2+ entry, 100 μM SKF 96365 partly inhibited thapsigargin- or uridine trisphos-phate (UTP)-induced capacitative Ca2+ entry. We also investigated the mechanisms underlying the decay of the SKF 96365-induced [Ca2+]i transient. Inhibition of the plasma membrane Ca2+ pump with La3+ or Gd3+, or lowering extracellular Na+ level to 0.35 mM, significantly increased the SKF 96365-induced [Ca2+]i transient. In contrast, the mitochondrial uncoupler carbonylcyanide m-chlorophenylhydrazone had little effect. In Ca2+-free medium, the thapsigargin-induced [Ca2+]i increase was greatly reduced by pretreatment with SKF 96365. Collectively, we have found that besides its well-known inhibitory
action on capacitative Ca2+ entry in many cell types, in MDCK cells SKF 96365 exerted multiple and complex effects on Ca2+ signaling. It induced a considerable increase in [Ca2+]i by releasing Ca2+ from the endoplasmic reticulum store followed by capacitative Ca2+ entry. It also caused a direct Ca2+ entry. The decay of the SKF 96365 response was significantly governed by efflux via the plasma membrane Ca2+ pump or Na+/Ca2+ exchange. Sequestration by mitochondria or the endoplasmic reticulum played a minor role. We caution use of SKF 96365 as
an inhibitor of capacitative Ca2+ entry.
Received: 21 September 1998 / Accepted: 2 December 1998 相似文献
7.
过氧化氢诱导牛主动脉内皮细胞损伤和胞内Ca2+升高及钙拮抗剂的抑制作用 总被引:3,自引:0,他引:3
为探讨缺氧/缺血过程中自由基损伤与钙超载的关系,观察了过氧化氢(H2O2)诱导培养牛主动脉内皮细胞(BAEC)的损伤和胞内游离钙([Ca2+]i)的变化。结果表明,H2O2可剂量、时间依赖地诱导BAEC活性下降(MTT值下降),脂质过氧化产物丙二醛(MDA)生成显著增加,同时伴有[Ca2+]i迅速显著升高。钙拮抗剂硝苯地平可剂量依赖地抑制H2O2引起的[Ca2+]i升高;同时能显著升高BAEC的MTT值,降低MDA生成,有效对抗H2O2诱导的BAEC损伤。提示,H2O2诱导内皮损伤可能与升高[Ca2+]i有关,Ca2+超载可能是活性氧致损伤的途径之一。钙拮抗剂对活性氧损伤具有一定保护作用。 相似文献
8.
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。 相似文献
9.
《药学学报》2009,44(5):473-479
观察大鼠离体胃体环行肌和胃底环行肌不同的药理学特征,分析核苷及核苷酸类物质诱发胃体环行肌收缩反应的作用特点和受体机制。制备大鼠离体胃体环行肌和胃底环行肌标本,利用受体药理学技术观察药物诱发的收缩反应。在胃体环行肌KCl所致收缩反应与胃底环行肌无显著性差别;但是,CCh收缩胃体环行肌的EC50值 [(0.45 ± 0.15) μmol·L−1] 显著高于胃底环行肌 [(0.20 ± 0.09) μmol·L−1, P < 0.01]。5-HT和His收缩两种标本的EC50值无显著差异 (P > 0.05); 但是, 在胃体环行肌5-HT和His产生收缩反应的Emax值 [(0.81 ± 0.26) 和 (0.88 ± 0.27) g] 显著小于胃底环行肌 [(2.67 ± 0.61) 和 (1.90 ± 0.68) g, P < 0.01]。在预收缩胃体环行肌,ATP (0.1~3 000 μmol·L−1) 诱发浓度依赖性收缩反应,未见舒张反应;在预收缩胃底环行肌标本,同浓度ATP诱发先舒张后收缩的双相反应,并呈浓度依赖性。ATP、UTP、ADP、2-MeSATP和α, β-MeATP浓度依赖性诱发大鼠胃体环行肌收缩反应,2-MeSATP的EC50值为 (7.2 ± 5.2) nmol·L−1比Ach [(3.47 ± 1.20) μmol·L−1] 低500倍;各药物产生收缩反应的效价序列为:2-MeSATP>>ADP>ATP=UTP>α, β-MeATP>>腺苷。酚妥拉明、普萘洛尔、阿托品及河豚毒素不影响ATP和UTP诱发的胃体环行肌收缩反应。研究结果表明, 大鼠胃体环行肌的药理学特征明显不同于胃底环行肌; 核苷酸类物质通过某种特殊的P2Y受体介导胃体环行肌收缩反应,是调节胃体环行肌收缩功能的重要介质。
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10.
阿米洛利对压力超负荷心肌肥厚大鼠心肌细胞内游离钙的影响 总被引:1,自引:1,他引:0
目的:观察阿米洛利预防性给药对压力超负荷心肌肥厚大鼠心肌细胞[Ca2+]i 影响。方法:以Fura-2/AM为指示剂,测定单细胞[Ca2+]i。结果:压力超负荷大鼠左室心肌细胞[Ca2+]i 升高,阿米洛利和依那普利组则[Ca2+]i 明显降低。给予KCl,NE刺激后,给药组左室心肌细胞[Ca2+]i 的增加值明显低于左室肥厚组,百日咳毒素(PTX,100 ng·L-1) 处理5 h 后,其静息[Ca2+]i 无显著变化,但抑制NE诱导左室心肌细胞[Ca2+]i 升高,该作用在左室肥厚组更明显,对KCl 刺激引起的[Ca2+]i 升高,给药组无影响,左室肥厚组的升高值略有增加。结论:NE所致心肌细胞[Ca2+]i 升高与PTX敏感的G 蛋白有关,肥厚时此途径亢进。 相似文献
11.
Liao WC Huang CC Cheng HH Wang JL Lin KL Cheng JS Chai KL Hsu PT Tsai JY Fang YC Lu YC Chang HT Huang JK Chou CT Jan CR 《Archives of toxicology》2009,83(1):61-68
The effect of calmidazolium on cytosolic free Ca2+ concentrations ([Ca2+]i) and viability has not been explored in human hepatoma cells. This study examined whether calmidazolium altered [Ca2+]i and caused cell death in HA59T cells. [Ca2+]i and cell viability were measured using the fluorescent dyes fura-2 and WST-1, respectively. Calmidazolium at concentrations
≥1 μM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 1.5 μM. The Ca2+ signal was reduced partly by removing extracellular Ca2+. Calmidazolium induced Mn2+ quench of fura-2 fluorescence implicating Ca2+ influx. The Ca2+ influx was insensitive to L-type Ca2+ entry blockers, but was inhibited partly by enhancing or inhibiting protein kinase C activity. In Ca2+-free medium, after pretreatment with 1 μM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), calmidazolium-induced [Ca2+]i rises were largely inhibited; and conversely, calmidazolium pretreatment totally suppressed thapsigargin-induced [Ca2+]i rises. Inhibition of phospholipase C with 2 μM U73122 did not change calmidazolium-induced [Ca2+]i rises. At concentrations between 1 and 15 μM, calmidazolium induced apoptosis-mediated cell death. Collectively, in HA59T
hepatoma cells, calmidazolium induced [Ca2+]i rises by causing Ca2+ release from the endoplasmic reticulum in a phospholipase C-independent manner, and Ca2+ influx via protein kinase C-regulated Ca2+ entry pathway. Calmidazolium caused cytotoxicity via apoptosis. 相似文献
12.
Effect of the antidepressant maprotiline on calcium movement and the viability of renal tubular cells 总被引:1,自引:0,他引:1
Hsu SS Chen WC Jiann BP Chen JS Huang JK Chang HT Cheng HH Lo YK Ho CM Jan CR 《Archives of toxicology》2004,78(8):453-459
In Madin-Darby canine kidney (MDCK) cells, the effect of maprotiline, an antidepressant, on intracellular Ca2+ concentration ([Ca2+]i) was measured using fura-2. Maprotiline (>2.5 µM) caused a rapid rise of [Ca2+]i in a concentration-dependent manner (EC50 200 µM). Maprotiline-induced [Ca2+]i rise was reduced by removal of extracellular Ca2+ or by addition of La3+, but was not altered by voltage-gated Ca2+-channel blockers. Maprotiline-induced Mn2+ influx-associated fura-2 fluorescence quench directly suggests that maprotiline caused Ca2+ influx. In Ca2+-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+-ATPase, caused a monophasic [Ca2+]i rise, after which the increasing effect of maprotiline on [Ca2+]i was nearly abolished; also, pretreatment with maprotiline reduced a portion of thapsigargin-induced [Ca2+]i rise. U73122, an inhibitor of phospholipase C, abolished [Ca2+]i rise induced by ATP (but not by maprotiline). Overnight incubation with 1–10 µM maprotiline enhanced cell viability, but 20–50 µM maprotiline decreased it. These findings suggest that maprotiline rapidly increases [Ca2+]i in renal tubular cells by stimulating both extracellular Ca2+ influx and intracellular Ca2+ release, and may modulate cell proliferation in a concentration-dependent manner. 相似文献
13.
Ching-Hsein Chen Shu-Jem Su Kee-Lung Chang Mei-Wen Huang Soong-Yu Kuo 《Food and chemical toxicology》2009,47(9):2344-2350
Diallyl sulfide (DAS), one of the major organosulfur compounds (OSCs) of garlic, is recognized as a group of potential chemoproventive compounds. In this study, we examines the early signaling effects of DAS on renal cells loaded with Ca2+-sensitive dye fura-2. It was found that DAS caused an immediate and sustained rise of [Ca2+]i in a concentration-dependent manner (EC50 = 2.32 mM). DAS also induced a [Ca2+]i elevation when extracellular Ca2+ was removed, but the magnitude was reduced by 45%. Depletion of intracellular Ca2+ stores with CCCP, a mitochondrial uncoupler, did not affect DAS’s effect. In Ca2+-free medium, the DAS-induced [Ca2+]i rise was abolished by depleting stored Ca2+ with thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor). DAS-caused [Ca2+]i rise in Ca2+-containing medium was not affected by modulation of protein kinase C activity. The DAS-induced Ca2+ influx was blocked by nicardipine. U73122, an inhibitor of phospholipase C, abolished ATP (but not DAS)-induced [Ca2+]i rise. Additionally, pretreatment with DAS for 24 h decreased cell viability in a concentration-dependent manner. Furthermore, DAS-induced cell death involved apoptotic events. These findings suggest that diallyl sulfide induced a significant rise in [Ca2+]i in MDCK renal tubular cells by stimulating both extracellular Ca2+ influx and thapsigargin-sensitive intracellular Ca2+ release via as yet unidentified mechanisms. 相似文献
14.
Ulrich Jahnel Hermann Nawrath Ru-Chi Shieh Virendra K. Sharma Daniel J. Williford Shey-Shing Sheu 《Naunyn-Schmiedeberg's archives of pharmacology》1992,346(1):88-93
Summary The effects of 1-adrenoceptor stimulation by phenylephrine (PE) and -adrenoceptor stimulation by isoprenaline (ISO) on Ca2+ current (ICa) and free intracellular Ca2+ concentration ([Ca2+]i) were studied in isolated atrial myocytes from rat hearts. PE did not significantly affect the magnitude of ICa, whereas large increases of peak ICa were observed in response to ISO. In electrically driven cells, PE evoked a concentration-dependent, gradual increase in diastolic [Ca2+]i and, initially, an increase in the height of peak [Ca2+]i transients. When the diastolic [Ca2+]i was increased to a greater extent, the amplitude of [Ca2+]i transients was decreased. Simultaneous measurements of [Ca2+]i and membrane potential showed that the increase in diastolic [Ca2+]i was associated with a depolarization of the membrane, and the greater amplitude of [Ca2+]i transients with a prolongation of the action potential (AP). The PE-induced increase in diastolic [Ca2+]i was eliminated when the cells were voltage-clamped at the original resting membrane potential (RP); under these conditions, an increase in [Ca2+]i transients was observed in response to PE. ISO usually caused larger increases in the amplitude of [Ca2+]i transients with only minor changes in diastolic [Ca2+]i. These results suggest that PE and ISO increase the amplitude of [Ca2+]i transients in rat atrium in different ways. The increase in [Ca2+]i transients in response to -adrenoceptor stimulation is commonly thought to be mediated by a greater conductance of voltage-dependent Ca2+ channels causing a greater Ca2+ influx and a release of more Ca2+ from the sarcoplasmic reticulum during the AP. The increase in diastolic [Ca2+]i in response to PE is probably a consequence of the depolarization of the membrane, possibly involving the voltage-dependent Na+-Ca2+ exchange mechanism. The increase in the amplitude of the [Ca2+]i transients in response to PE may be ascribed both to the initial increase in diastolic [Ca2+]i and the prolongation of the AP.
Send offprint requests to H. Nawrath at the above address 相似文献
15.
Xie-Nan Huang Tetsuhiro Hisayama Issei Takayanagi 《Naunyn-Schmiedeberg's archives of pharmacology》1990,341(1-2):80-87
Summary The modes by which Endothelin-1 (ET) induces Ca2+-influx and the relative functional importance of the different sources of Ca2+ for ET-induced contraction were studied using fura 2-loaded and unloaded rat aortic strips. ET caused an increase in the cytosolic free Ca2+ level ([Ca2+]i) followed by a tonic contraction in Ca2+-containing solution, and produced a transient elevation of [Ca2+]i followed by a small sustained contraction in Ca2+-free medium. ET also stimulated 45Ca influx into La2+-inaccessible fraction significantly. With the same change of [Ca2+]i, ET caused a larger tension than that induced by high K. ET-induced contraction and [Ca2+]i elevation were not significantly inhibited by 0.1–0.3 M nicardipine which nearly abolished the contraction and [Ca+]i elevation produced by high K. During treatment of the strips with high K, addition of ET induced further increases in [Ca2+]i and muscle tension, and vice versa. In Ca2+-free medium, ET-induced contraction was influenced neither by ryanodine-treatment nor by high K-treatment, although the former attenuated and the latter potentiated the [Ca2+]i transient induced by ET. Further, the ET-induced sustained contraction under Ca2+-free conditions began to develop after the [Ca2+]i level returned to the baseline. Thus, it seems that the Ca2+ released from the ryanodine-sensitive and -insensitive Ca2+ stores by ET may provide only a minor or indirect contribution, if any, to the tension development. ET might cause a contraction mainly by stimulating Ca2+-influx through Ca2+ channel(s) other than voltage-dependent Ca2+ channels in character, and by increasing the sensitivity of the contractile filaments to Ca2+ or activating them Ca2+-independently.Visiting from Zun Yi Medical College, China
Send offprint requests to I. Takayanagi at the above address 相似文献
16.
Wang JP Chang LC Kuan YH Tsao LT Huang LJ Kuo SC 《Naunyn-Schmiedeberg's archives of pharmacology》2004,370(5):353-360
2-Benzyloxybenzaldehyde (CCY1a) inhibited the formyl-Met-Leu-Phe (fMLP)-induced elevation of cytosolic [Ca2+] ([Ca2+]i) in rat neutrophils. The late plateau phase, but not the initial Ca2+ spike, of the fMLP-induced [Ca2+]i change was inhibited by CCY1a. In the absence of external Ca2+, CCY1a had no appreciable effect on either the fMLP- or cyclopiazonic acid (CPA)-induced [Ca2+]i elevation. CCY1a failed to inhibit [Ca2+]i changes induced by N-ethylmaleimide, GEA3162, ionomycin or sphingosine, but slightly inhibited the Ca2+ signals elicited by ATP or interleukin-8 (IL-8). In a classical Ca2+ readdition protocol, addition of CCY1a after cell activation strongly inhibited the [Ca2+]i response to fMLP, whilst that to CPA was only slightly reduced. CCY1a nearly abrogated the fMLP-stimulated Mn2+ influx but was less effective on the CPA-induced response. CCY1a attenuated the levels of tyrosine-phosphorylated bands in the 70–85 kDa molecular mass range. CCY1a had no effect on the basal [Ca2+]i level, the pharmacologically isolated plasma membrane Ca2+-ATPase activity or on the mitochondrial membrane potential. Thus, CCY1a blocks fMLP-induced Ca2+ entry into neutrophils probably by blocking the relevant Ca2+ channel directly or, alternatively, indirectly through the attenuation of tyrosine phosphorylation of some cellular proteins. 相似文献
17.
Wei-Zhe Liang Chiang-Ting Chou Shu-Shong Hsu Wei-Chuan Liao Pochuen Shieh Daih-Huang Kuo Hui-Wen Tseng Chun-Chi Kuo Chung-Ren Jan 《Toxicology letters》2015
Eugenol, a natural phenolic constituent of clove oil, has a wide range of applications in medicine as a local antiseptic and anesthetic. However, the effect of eugenol on human glioblastoma is unclear. This study examined whether eugenol elevated intracellular free Ca2+ levels ([Ca2+]i) and induced apoptosis in DBTRG-05MG human glioblastoma cells. Eugenol evoked [Ca2+]i rises which were reduced by removing extracellular Ca2+. Eugenol-induced [Ca2+]i rises were not altered by store-operated Ca2+ channel blockers but were inhibited by the PKC inhibitor GF109203X and the transient receptor potential channel melastatin 8 (TRPM8) antagonist capsazepine. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (TG) or 2,5-di-tert-butylhydroquinone (BHQ) abolished eugenol-induced [Ca2+]i rises. The phospholipase C (PLC) inhibitor U73122 significantly inhibited eugenol-induced [Ca2+]i rises. Eugenol killed cells which were not reversed by prechelating cytosolic Ca2+ with 1,2-bis(2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid-acetoxymethyl ester (BAPTA-AM). Eugenol induced apoptosis through increasing reactive oxygen species (ROS) production, decreasing mitochondrial membrane potential, releasing cytochrome c and activating caspase-9/caspase-3. Together, in DBTRG-05MG cells, eugenol evoked [Ca2+]i rises by inducing PLC-dependent release of Ca2+ from the endoplasmic reticulum and caused Ca2+ influx possibly through TRPM8 or PKC-sensitive channels. Furthermore, eugenol induced the mitochondrial apoptotic pathway. 相似文献
18.
Cheng JS Huang CC Chou CT Jan CR 《Naunyn-Schmiedeberg's archives of pharmacology》2007,376(3):185-194
The effect of the cardiovascular drug carvedilol on cytosolic free Ca2+ concentrations ([Ca2+]i) and viability has not been explored in human hepatoma cells. This study examined whether carvedilol altered [Ca2+]i and caused cell death in HA59T cells. [Ca2+]i and cell viability were measured using the fluorescent dyes fura-2 and WST-1, respectively. Carvedilol at concentrations
≥1 μM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 20 μM. The Ca2+ signal was reduced partly by removing extracellular Ca2+. Carvedilol induced Mn2+ quench of fura-2 fluorescence, implicating Ca2+ influx. The Ca2+ influx was sensitive to La3+, econazole, nifedipine, and SKF96365. In Ca2+-free medium, after pretreatment with 1 μM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), carvedilol-induced [Ca2+]i rises were abolished; and conversely, carvedilol pretreatment inhibited a major part of thapsigargin-induced [Ca2+]i rises. Inhibition of phospholipase C with 2 μM U73122 did not change carvedilol-induced [Ca2+]i rises. At concentrations between 1 and 50 μM, carvedilol killed cells in a concentration-dependent manner. The cytotoxic
effect of 1 μM (but not 30 μM) carvedilol was fully reversed by prechelating cytosolic Ca2+ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Apoptosis was induced by 30
(but not 1) μM carvedilol. Collectively, in HA59T hepatoma cells, carvedilol induced [Ca2+]i rises by causing Ca2+ release from the endoplasmic reticulum in a phospholipase-C-independent manner and Ca2+ influx via store-operated Ca2+ channels. Carvedilol-caused cytotoxicity was mediated by Ca2+ and apoptosis in a concentration-dependent manner. 相似文献
19.
Wei-Chuan ChenShu-Shong Hsu Chiang-Ting Chou Chun-Chi KuoJong-Khing Huang Yi-Chien FangHong-Tai Chang Jeng-Yu TsaiWei-Chuan Liao Being-Whey WangPochuen Shieh Daih-Huang KuoChung-Ren Jan 《Toxicology in vitro》2011,25(3):636-643
The effect of diallyl disulfide (DADS) on cytosolic Ca2+ concentrations ([Ca2+]i) and viability in PC3 human prostate cancer cells is unclear. This study explored whether DADS changed [Ca2+]i in PC3 cells by using fura-2. DADS at 50-1000 μM increased [Ca2+]i in a concentration-dependent manner. The signal was reduced by removing Ca2+. DADS-induced Ca2+ influx was not inhibited by nifedipine, econazole, SK&F96365, and protein kinase C modulators; but was inhibited by aristolochic acid. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitors thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) nearly abolished DADS-induced [Ca2+]i rise. Incubation with DADS inhibited thapsigargin or BHQ-induced [Ca2+]i rise. Inhibition of phospholipase C with U73122 did not alter DADS-induced [Ca2+]i rise. At 500-1000 μM, DADS killed cells in a concentration-dependent manner. The cytotoxic effect of DADS was partly reversed by prechelating cytosolic Ca2+ with 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA). Propidium iodide staining suggests that DADS (500 μM) induced apoptosis in a Ca2+-independent manner. Annexin V/PI staining further shows that 10 μM and 500 μM DADS both evoked apoptosis. DADS also increased reactive oxygen species (ROS) production. Collectively, in PC3 cells, DADS induced [Ca2+]i rise probably by causing phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx via phospholipase A2-sensitive channels. DADS induced Ca2+-dependent cell death, ROS production, and Ca2+-independent apoptosis. 相似文献