C R Jan

VGHKS Kaohsiung Veterans General Hospital, Kao-hsiung-shih, Kaohsiung, Taiwan

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Publications (96)262.77 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study evaluated the effects of thimerosal, a vaccine preservative, on cytosolic free Ca2+ concentrations ([Ca2+]i) in human prostate cancer cells (PC3). Thimerosal (10–200 µM) increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced partly by removing extracellular Ca2+. Thimerosal-induced Ca2+ influx was inhibited by econazole, SKF963656, the phospholipase A2 inhibitor aristolochic acid, and protein kinase C modulators [phorbol 12-myristate 13-acetate (PMA) and GF109203X]. In Ca2+-free medium, a 200-µM thimerosal-induced [Ca2+]i rise was partly inhibited after pretreatment with 2,5-di-tert-butylhydroquinone (BHQ) (an endoplasmic reticulum Ca2+ pump inhibitor). Thimerosal at 1–7 µM induced cell death in a concentration-dependent manner that was not reversed when cytosolic Ca2+ was chelated with 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA). Propidium iodide staining suggests that apoptosis played a role in the death. Collectively, in PC3 cells, thimerosal induced [Ca2+]i rise by causing Ca2+ release from the endoplasmic reticulum and Ca2+ influx via store-operated Ca2+ channels in a manner regulated by protein kinase C and phospholipase A2. Thimerosal also induced cell death in a Ca2+-independent apoptotic manner. Drug Dev Res 72: 330–336, 2011. © 2011 Wiley-Liss, Inc.
    Drug Development Research 06/2011; 72(4). · 0.87 Impact Factor
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    ABSTRACT: The current study explored whether capsazepine changed basal cytosolic free Ca2+ concentrations ([Ca2+]i) levels in suspended Madin Darby canine kidney (MDCK) cells cells by using fura-2 as a Ca2+-selective fluorescent dye. At concentrations of 10–200 µM, capsazepine increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was partially reduced by 40% by removing extracellular Ca2+. Capsazepine induced Mn2+ quench of fura-2 fluorescence, indirectly implicating Ca2+ entry. Capsazepine-induced Ca2+ influx was unchanged by L-type Ca2+ entry inhibitors and protein kinase C modulators [phorbol 12-myristate 13-acetate (PMA) and GF109203X]. In Ca2+-free medium, 100 µM capsazepine-induced Ca2+ release was substantially suppressed by pretreatment with thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor). Pretreatment with capsazepine nearly abolished thapsigargin-induced Ca2+ release. Inhibition of phospholipase C with U73122 did not change capsazepine-induced [Ca2+]i rises. Collectively, in MDCK cells, capsazepine induced [Ca2+]i rises by causing phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx via non-L-type Ca2+ channels. Drug Dev Res 72: 323–329, 2011. © 2010 Wiley-Liss, Inc.
    Drug Development Research 06/2011; 72(4). · 0.87 Impact Factor
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    ABSTRACT: The effect of nortriptyline, a tricyclic antidepressant, on Ca2+ regulation and viability in human prostate cancer cells (PC3) is unclear. The present study examined whether nortriptyline altered basal [Ca2+]i levels in suspended PC3 cells using fura-2 as a Ca2+-sensitive fluorescent probe. Nortriptyline (50–500 µM) increased [Ca2+]i in a concentration-dependent fashion. The Ca2+ signal was partially reduced by removing extracellular Ca2+, indicating that Ca2+ entry and release both contributed to the [Ca2+]i rise. Nortriptyline induced Mn2+ influx, leading to quench of fura-2 fluorescence, suggesting Ca2+ influx. This Ca2+ influx was inhibited by activation of protein kinase C, but not by inhibition of L-type Ca2+ channels. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor, thapsigargin nearly abolished nortriptyline-induced Ca2+ release. Conversely, pretreatment with nortriptyline greatly reduced the inhibitor-induced [Ca2+]i rise, suggesting that nortriptyline released Ca2+ from the endoplasmic reticulum. Inhibition of phospholipase C did not change the nortriptyline-induced [Ca2+]i rise. Nortriptyline at a concentration of 10 µM increased viability in a Ca2+-independent manner. At 50 µM, nortriptyline killed 45% of cells. Nortriptyline at 10 µM did not induce apoptosis, but at 50 µM induced significant apoptosis measured by propidium iodide staining. Together, in PC3 cells, nortriptyline induced [Ca2+]i rises by causing the phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx via the protein kinase C-sensitive pathway. Nortriptyline also induced both cell proliferation and death in a concentration-dependent manner. Apoptosis was involved in the cell death. Drug Dev Res 71:323–330, 2010. © 2010 Wiley-Liss, Inc.
    Drug Development Research 08/2010; 71(5). · 0.87 Impact Factor
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    ABSTRACT: The effect of thimerosal on cytosolic free Ca(2+) concentrations ([Ca(2+)](i) ) in human oral cancer cells (OC2) is unclear. This study explored whether thimerosal changed basal [Ca(2+)](i) levels in suspended OC2 cells using fura-2. Thimerosal at concentrations between 1and 50 microM increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced partly by removing extracellular Ca( 2+). Thimerosal-induced Ca(2+) influx was not blocked by L-type Ca(2+) entry inhibitors and protein kinase C modulators (phorbol 12-myristate 13-acetate [PMA] and GF109203X). In Ca(2+)-free medium, 50 microM thimerosal failed to induce a [Ca(2+)](i) rise after pretreatment with thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor). Inhibition of phospholipase C with U73122 did not change thimerosal-induced [Ca(2+)](i) rises. At concentrations between 5 and 10 microM, thimerosal killed cells in a concentration-dependent manner. The cytotoxic effect of 8 muM thimerosal was potentiated by prechelating cytosolic Ca(2+) with the Ca(2+) chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetate/acetomethyl (BAPTA/ AM). Flow cytometry data suggested that 1-7 microM thimerosal-induced apoptosis in a concentration-dependent manner. Collectively, in OC2 cells, thimerosal-induced [Ca(2+)](i) rises by causing phospholipase C-independent Ca(2+) release from the endoplasmic reticulum and Ca(2+) influx through non-L-type Ca(2+) channels. Thimerosal killed cells in a concentration-dependent manner through apoptosis.
    Human & Experimental Toxicology 09/2009; 28(5):301-8. · 1.31 Impact Factor
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    ABSTRACT: The effect of melittin on cytosolic free Ca(2+) concentration ([Ca(2+)](i)) and viability is largely unknown. This study examined whether melittin alters Ca(2+) levels and causes Ca(2+)-dependent cell death in Madin-Darby canine kidney (MDCK) cells. [Ca(2+)](i) and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Melittin at concentrations above 0.5 microM increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced by 75% by removing extracellular Ca(2+). The melittin-induced Ca(2+) influx was also implicated by melittin-caused Mn(2+) influx. After pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), melittin-induced Ca(2+) release was inhibited; and conversely, melittin pretreatment abolished thapsigargin-induced Ca(2+) release. At concentrations of 0.5-20 microM, melittin killed cells in a concentration-dependent manner. The cytotoxic effect of 0.5 microM melittin was nearly completely reversed by prechelating cytosolic Ca(2+) with BAPTA. Melittin at 0.5-2 microM caused apoptosis as assessed by flow cytometry of propidium iodide staining. Collectively, in MDCK cells, melittin induced a [Ca(2+)](i) rise by causing Ca(2+) release from endoplasmic reticulum and Ca(2+) influx from extracellular space. Furthermore, melittin can cause Ca(2+)-dependent cytotoxicity in a concentration-dependent manner.
    Human &amp Experimental Toxicology 06/2008; 27(5):417-24. · 1.45 Impact Factor
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    ABSTRACT: The effect of MK-886 (3-[1-(p-chlorobenzyl)-5-(isopropyl)-3-tert-butylthioindol-2-yl]-2, 2-dimethylpropanoic acid), a compound widely used to inhibit leukotriene synthesis, on cytosolic free Ca2+ concentrations ([Ca2+]i) in osteosarcoma cells has not been explored. This study examined whether MK-886 altered [Ca2+]i levels in suspended MG63 human osteosarcoma cells using fura-2. MK-886 at 0.1 μM and above increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced partly by removing extracellular Ca2+. MK-886 induced Mn2+ quenching of fura-2 fluorescence, implicating Ca2+ entry. MK-886-induced Ca2+ influx was inhibited by store-operated Ca2+ entry inhibitors, nifedipine, econazole, and SKF96365; and by the protein kinase C modulators, phorbol 12-myristate 13-acetate (PMA) and GF109203X. In Ca2+-free medium, after pretreatment with 5 μM MK-886, 1 μM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor)-induced [Ca2+]i rises were abolished; conversely, thapsigargin pretreatment nearly abolished MK-886-induced [Ca2+]i rises. Inhibition of phospholipase C with U73122 did not change MK-886-induced [Ca2+]i rises. Collectively, in MG63 osteosarcoma cells, MK-886 induced [Ca2+]i rises by causing phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx via protein kinase C-regulated store-operated Ca2+ entry. Drug Dev Res 69: 49–57, 2008. © 2008 Wiley-Liss, Inc.
    Drug Development Research 03/2008; 69(2). · 0.87 Impact Factor
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    ABSTRACT: Thimerosal is a mercury-containing preservative in some vaccines. The effect of thimerosal on human gastric cancer cells is unknown. This study shows that in cultured human gastric cancer cells (SCM1), thimerosal reduced cell viability in a concen- tration- and time-dependent manner. Thimerosal caused apopto- sis as assessed by propidium iodide-stained cells and caspase-3 activation. Although immunoblotting data revealed that thimer- osal could activate the phosphorylation of extracellular signal- regulated kinase, c-Jun NH2-terminal protein kinase, and p38 mitogen-activated protein kinase (p38 MAPK), only SB203580 (a p38 MAPK inhibitor) partially prevented cells from apoptosis. Thimerosal also induced (Ca21)i increases via Ca 21 influx from the extracellular space. However, pretreatment with (bis(o- aminophenoxy)ethane-N,N,N#,N#-tetraacetate)/AM, a Ca21 che- lator, to prevent thimerosal-induced (Ca21)i increases did not protect cells from death. The results suggest that in SCM1 cells, thimerosal caused Ca21-independent apoptosis via phosphorylat-
    Toxicological Sciences 08/2007; 100(1):109-117. · 4.33 Impact Factor
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    ABSTRACT: Riluzole is a drug used in the treatment of amyotrophic lateral sclerosis; however, its in vitro action is unclear. In this study, the effect of riluzole on intracellular Ca2+ concentration ([Ca2+]i) in Madin-Darby canine kidney (MDCK) cells was investigated using the Ca2+ -sensitive fluorescent dye, fura-2. Riluzole (100-500 microM) caused a rapid and sustained increase of [Ca2+]i in a concentration-dependent manner (EC50 = 150 microM). Some 40 and 50% of this [Ca2+]i increase was prevented by the removal of extracellular Ca2+ and the addition of La3+, respectively, but was unchanged by dihydropyridines, verapamil and diltiazem. In Ca2+ -free medium, thapsigargin - an inhibitor of the endoplasmic reticulum (ER) Caz+ -ATPase--caused a monophasic [Ca2+]i increase, after which the increasing effect of riluzole on [Ca2+]i was attenuated by 70%; in addition, pre-treatment with riluzole abolished thapsigargin-induced [Ca2+]i increases. U73122, an inhibitor of phospholipase C (PLC), abolished ATP (but not riluzole)-induced [Ca2+]i increases. At concentrations of 250 and 500 microM, riluzole killed 40 and 95% cells, respectively. The cytotoxic effect of riluzole (250 microM) was unaltered by pre-chelating cytosolic Ca2+ with BAPTA. Collectively, in MDCK cells, riluzole rapidly increased [Ca2+]i by stimulating extracellular Ca2+ influx via an La3+ -sensitive pathway and intracellular Ca2+ release from the ER via, as yet, unidentified mechanisms. Furthermore, riluzole caused Ca2+ -unrelated cytotoxicity in a concentration-dependent manner.
    Human &amp Experimental Toxicology 09/2006; 25(8):461-9. · 1.45 Impact Factor
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    ABSTRACT: The effect of the carcinogen safrole on intracellular Ca2+ mobilization and on viability of human PC3 prostate cancer cells was examined. Cytosolic free Ca2+ levels ([Ca2+]i) were measured by using fura-2 as a probe. Safrole at concentrations above 10 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 350 microM. The Ca2+ signal was reduced by more than half after removing extracellular Ca2+ but was unaffected by nifedipine, nicardipine, nimodipine, diltiazem, or verapamil. In Ca2+-free medium, after treatment with 650 microM safrole, 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) failed to release Ca2+. Neither inhibition of phospholipase C with U73122 nor modulation of protein kinase C activity affected safrole-induced Ca2+ release. Overnight incubation with 0.65-65 microM safrole did not affect cell viability, but incubation with 325-625 microM safrole decreased viability. Collectively, the data suggest that in PC3 cells, safrole induced a [Ca2+]i increase by causing Ca2+ release from the endoplasmic reticulum in a phospholipase C- and protein kinase C-independent fashion, and by inducing Ca2+ influx. Safrole can decrease cell viability in a concentration-dependent manner.
    Journal of Receptor and Signal Transduction Research 01/2006; 26(3):199-212. · 1.63 Impact Factor
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    ABSTRACT: Econazole is an antifungal drug with different in vitro effects. However, econazole's effect on osteoblast-like cells is unknown. In human MG63 osteosarcoma cells, the effect of econazole on intracellular Ca2+ concentrations ([Ca2+]i) was explored by using fura-2. At a concentration of 0.1 microM, econazole started to cause a rise in [Ca2+]i in a concentration-dependent manner. Econazole-induced [Ca2+]i rise was reduced by 74% by removal of extracellular Ca2+. The econazole-induced Ca2+ influx was mediated via a nimodipine-sensitive pathway. In Ca2+ -free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca+ -ATPase, caused a [Ca2+]i rise, after which the increasing effect of econazole on [Ca2+]i was abolished. Pretreatment of cells with econazole to deplete Ca2+ stores totally prevented thapsigargin from releasing Ca2+. U73122, an inhibitor of phospholipase C, abolished histamine (an inositol 1,4,5-trisphosphate-dependent Ca2+ mobilizer)-induced, but not econazole-induced, [Ca2+]i rise. Econazole inhibited 76% of thapsigargin-induced store-operated Ca2+ entry. These findings suggest that in MG63 osteosarcoma cells, econazole increases [Ca2+]i by stimulating Ca2+ influx and Ca2+ release from the endoplasmic reticulum via a phospholipase C-independent manner. In contrast, econazole acts as a potent blocker of store-operated Ca2+ entry.
    Human &amp Experimental Toxicology 10/2005; 24(9):453-8. · 1.45 Impact Factor
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    ABSTRACT: The effect of celecoxib on renal tubular cells is largely unexplored. In Madin Darby canine kidney (MDCK) cells, the effect of celecoxib on intracellular CaCa2+ concentration ([Ca2+]i) and proliferation was examined by using the Ca(2 +)-sensitive fluorescent dye fura-2 and the viability detecting fluorescent dye tetrazolium, respectively. Celecoxib (> or =1 micro M) caused an increase of [CaCa2+]i in a concentration-dependent manner. Celecoxib-induced [CaCa2+]i increase was partly reduced by removal of extracellular CaCa2+. Celecoxib-induced CaCa2+ influx was independently suggested by MnCa2+ influx-induced fura-2 fluorescence quench. In Ca(2 +)-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2 +)-ATPase, caused a monophasic [CaCa2+]i increase, after which celecoxib only induced a tiny [CaCa2+]i increase; conversely, pretreatment with celecoxib completely inhibited thapsigargin-induced [CaCa2+]i increases. U73122, an inhibitor of phospholipase C, abolished ATP (but not celecoxib)-induced [CaCa2+]i increases. Overnight incubation with 1 or 10 micro M celecoxib decreased cell viability by 80% and 100%, respectively. These data indicate that celecoxib evokes a [CaCa2+]i increase in renal tubular cells by stimulating both extracellular CaCa2+ influx and intracellular CaCa2+ release and is highly toxic to renal tubular cells in vitro.
    Journal of Receptor and Signal Transduction Research 02/2005; 25(4-6):237-49. · 1.63 Impact Factor
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    ABSTRACT: The effects of the environmental toxicant, triethyltin, on Ca2+ mobilization in Madin-Darby canine kidney (MDCK) cells have been examined. Triethyltin induced an increase in cytosolic free Ca2+ levels ([Ca2+]i) at concentrations larger than 2 microM in a concentration-dependent manner. Within 5 min, the [Ca2+]i signal was composed of a gradual rise and a sustained phase. The [Ca2+]i signal was partly reduced by removing extracellular Ca2+. In Ca(2+)-free medium, pretreatment with thapsigargin (1 microM), an endoplasmic reticulum Ca2+ pump inhibitor, reduced 50 microM triethyltin-induced [Ca2+]i increase by 80%. Conversely, pretreatment with triethyltin abolished thapsigargin-induced Ca2+ release. Pretreatment with U73122 (2 microM) to inhibit phospholipase C-coupled inositol 1,4,5-trisphosphate formations failed to alter 50 microM triethyltin-induced Ca2+ release. Incubation with triethyltin at a concentration (1 microM) that did not increase basal [Ca2+]i for 3 min did not alter ATP (10 microM)- and bradykinin (1 microM)-induced [Ca2+]i increases. Collectively, this study shows that triethyltin altered Ca2+ movement in renal tubular cells by releasing Ca2+ from multiple stores in an inositol 1,4,5-trisphosphate-independent manner, and by inducing Ca2+ influx.
    Human &amp Experimental Toxicology 09/2002; 21(8):457-62. · 1.45 Impact Factor
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    ABSTRACT: The effects of timosaponin A-III (TA-III), from Rhizoma Anemarrhenae, on Ca(2+) mobilization in vascular endothelial cells and smooth muscle cells and on vascular tension have been explored. TA-III increased intracellular Ca(2+) concentrations ([Ca(2+)](i)) in endothelials cells at a concentration larger than 5 microM with an EC(50) of 15 microM, and increased [Ca(2+)](i) in smooth muscle cells at a concentration larger than 1 microM with an EC(50) of 8 microM. Within 5 min, the [Ca(2+)](i) signal was composed of a gradual rise, and the speed of rising depended on the concentration of TA-III. The [Ca(2+)](i) signal was abolished by removing extracellular Ca(2+) and was recovered after reintroduction of Ca(2+). The TA-III-induced [Ca(2+)](i) increases in smooth muscle cells were partly inhibited by 10 microM nifedipine or 50 microM La(3+), but was insensitive to 10 microM verapamil and diltiazem. TA-III (10-100 microM) inhibited 0.3 microM phenylephrine-induced vascular contraction, which was abolished by pretreatment with 100 microM N(omega)-nitro-L-arginine (L-NNA) or by denuding the aorta. TA-III also increased [Ca(2+)](i) in renal tubular cells with an EC(50) of 8 microM. Collectively, the results show for the first time that TA-III causes [Ca(2+)](i) increases in the vascular system. TA-III acted by causing Ca(2+) influx without releasing intracellular Ca(2+). TA-III induced relaxation of phenylephrine-induced vascular contraction via inducing release of nitric oxide from endothelial cells.
    Life Sciences 08/2002; 71(9):1081-90. · 2.56 Impact Factor
  • Muh Chiou Lin, Chung Ren Jan
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    ABSTRACT: The effect of the anti-anginal drug fendiline on intracellular free Ca(2+) levels ([Ca(2+)](i)) in a rabbit corneal epithelial cell line (SIRC) was explored using fura-2 as a fluorescent Ca(2+) indicator. At a concentration above 1 microM, fendiline increased [Ca(2+)](i) in a concentration-dependent manner with an EC(50) value of 7 microM. The [Ca(2+)](i) response consisted of an immediate rise and an elevated phase. Extracellular Ca(2+) removal decreased half of the [Ca(2+)](i )signal. Fendiline induced quench of fura-2 fluorescence by Mn(2+) (50 microM), suggesting the presence of Ca(2+) influx across the plasma membrane. This Ca(2+) influx was abolished by La(3+) (50 microM), but was insensitive to dihydropyridines, verapamil and diltiazem. Fendiline (10 microM)-induced store Ca(2+) release was largely reduced by pretreatment with thapsigargin (1 microM) (an endoplasmic reticulum Ca(2+) pump inhibitor) to deplete the endoplasmic reticulum Ca(2+). Conversely, pretreatment with 10 microM fendiline abolished thapsigargin-induced Ca(2+) release. Fendiline (10 microM)-induced Ca(2+) release was not altered by inhibiting phospholipase C with 2 microM 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). Cumulatively, this study shows that fendiline induced concentration-dependent [Ca(2+)](i )increases in corneal epithelial cells by releasing the endoplasmic reticulum Ca(2+) in a phospholipase C-independent manner, and by causing Ca(2+) influx.
    Life Sciences 08/2002; 71(9):1071-9. · 2.56 Impact Factor
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    ABSTRACT: The effect of gossypol, a compound found in cottonseed, on intracellular free Ca2+ levels ([Ca2+]i) in Chang liver cells were evaluated using fura-2 as a fluorescent Ca2+ indicator. Gossypol (0.2–5μM) increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 1.5μM. The [Ca2+]i response was composed of an initial rise and a slow decay to a sustained phase within 5min after drug application. Removal of extracellular Ca2+ markedly reduced the [Ca2+]i signals by 80±2%. Preincubation with 0.1mM La3+ or 10μM nimodipine abolished the Ca2+ influx. Gossypol (5μM)-induced release of intracellular Ca2+ was reduced by 75% by pretreatment with 1μM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete the endoplasmic reticulum Ca2+. Conversely, pretreatment with gossypol abolished thapsigargin-induced Ca2+ release. After pretreatment with 5μM gossypol in Ca2+-free medium for several min, addition of 3mM Ca2+ induced a [Ca2+]i increase of a magnitude nine-fold greater than control. Gossypol (5μM)-induced Ca2+ release was not affected by inhibiting phospholipase C with 2μM 1-(6-((17β-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). Together, this study shows that gossypol induced significant [Ca2+]i increases in Chang liver cells by releasing Ca2+ from intracellular pools in a phospholipase C-dissociated fashion and by causing La3+- and nimodipine-sensitive Ca2+ influx.
    Toxicon 07/2002; 40(7):851-856. · 2.92 Impact Factor
  • Life Sciences 05/2002; 70(26). · 2.56 Impact Factor
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    ABSTRACT: The effect of histamine on intracellular free Ca2+ levels ([Ca2+]i) in PC3 human prostate cancer cells and the underlying mechanism were evaluated using fura-2 as a Ca2+ dye. Histamine at concentrations between 0.1 and 50 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 1 microM. The [Ca2+]i response comprised an initial rise and a slow decay, which returned to baseline within 3 min. Extracellular Ca2+ removal inhibited 50% of the [Ca2+]i signal. In the absence of extracellular Ca2+, after cells were treated with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), 10 microM histamine did not increase [Ca2+]i. After pretreatment with 10 microM histamine in a Ca2+-free medium for several minutes, addition of 3 mM Ca2+ induced [Ca2+]i increases. Histamine (10 microM)-induced intracellular Ca2+ release was abolished by inhibiting phospholipase C with 2 microM 1-(6-((17 beta-3- methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), and by 10 microM pyrilamine but was not altered by 50 microM cimetidine. Collectively, the present study shows that histamine induced [Ca2+]i transients in PC3 human prostate cancer cells by stimulating H1 histamine receptors leading to Ca2+ release from the endoplasmic reticulum in an inositol 1,4,5-trisphosphate-dependent manner, and by inducing Ca2+ entry.
    Pharmacological Research 01/2002; 44(6):547-52. · 4.35 Impact Factor
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    S N Wu, C R Jan, H T Chiang
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    ABSTRACT: The fenamates, a family of nonsteroidal anti-inflammatory drugs that are derivatives of N-phenylanthranilic acid, are the inhibitors of cyclo-oxygenase. The ionic mechanism of actions of these compounds in osteoblasts is not well understood. The effects of the fenamates on ionic currents were investigated in a human osteoblast-like cell line (MG-63) with the aid of the whole-cell and inside-out configurations of the patch-clamp technique. In MG-63 cells, niflumic acid and meclofenamic acid increased K+ outward currents (IK). The niflumic acid-stimulated IK was reversed by subsequent application of iberiotoxin or paxilline, yet not by that of glibenclamide or apamin. In the inside-out configuration, niflumic acid (30 micromol/L) added to the bath did not modify single-channel conductance but increased the activity of large-conductance Ca2+-activated K+ (BKCa) channels. The EC50 values for niflumic acid- and meclofenamic acid-induced channel activity were 22 and 24 micromol/L, respectively. Niflumic acid (30 micromol/L) and meclofenamic acid (30 micromol/L) shifted the activation curve of BKCa channels to less positive membrane potentials. Membrane stretch potentiated niflumic acid-stimulated channel activity. The rank order of potency for the activation of BKCa channels in these cells was niflumic acid = meclofenamic acid > tolfenamic acid > flufenamic acid > nimesulide. Evans blue and nordihydroguaiaretic acid increased channel activity; however, indomethacin, piroxicam, and NS-398 had no effect on it. The fenamates can stimulate BKCa channel activity in a manner that seems to be independent of the action of these drugs on the prostaglandin pathway. The activation of the BKCa channel may hyperpolarize the osteoblast, thereby modulating osteoblastic function.
    Journal of Investigative Medicine 11/2001; 49(6):522-33. · 1.75 Impact Factor
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    ABSTRACT: Adenosine was shown to inhibit norepinephrine (NE) release from sympathetic nerve endings. The purpose of this study was to examine whether endogenous adenosine restrains NE and epinephrine release from the adrenal medulla. The effects of an adenosine receptor antagonist, 1,3-dipropyl-8-(p-sulfophenyl) xanthine (DPSPX), on epinephrine and NE release induced by intravenous administration of insulin in conscious rats were examined. Plasma catecholamines were measured by HPLC with an electrochemical detector. DPSPX significantly increased plasma catecholamine in both control rats and rats treated with insulin. The effect of DPSPX on plasma catecholamine was significantly greater in rats treated with insulin. Additional experiments were performed in adrenalectomized rats to investigate the contribution of the adrenal medulla to the effect of DPSPX on plasma catecholamine. The effect of DPSPX and insulin on epinephrine in adrenalectomized rats was significantly reduced compared with that of the controls. Finally, we tested whether endogenous adenosine restrains catecholamine secretion partially through inhibiting the renin-angiotensin system. The effect of DPSPX on plasma catecholamine in rats pretreated with captopril (an angiotensin-converting enzyme inhibitor) was reduced. These results demonstrate that under basal physiological conditions, endogenous adenosine tonically inhibits catecholamine secretion from the adrenal medulla, and this effect is augmented when the sympathetic system is stimulated. The effect of endogenous adenosine on catecholamine secretion from the adrenal medulla is achieved partially through the inhibitory effect of adenosine on the renin-angiotensin system.
    Journal of Biomedical Science 10/2001; 8(5):389-94. · 2.46 Impact Factor
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    ABSTRACT: 1. The effects of the antianginal drug fendiline (N-[3,3-diphenylpropyl]-alpha-methyl-benzylamine) on intracellular free Ca2+ levels ([Ca2+](i)) in Chang liver cells were evaluated using fura-2 as a fluorescent Ca2+ indicator. 2. Fendiline (1-100 micromol/L) increased [Ca2+](i) in a concentration-dependent manner, with an EC50 of 25 micromol/L. 3. The [Ca2+](i) response was composed of an initial rise and a slow decay to a sustained phase. Removal of extracellular Ca2+ partly reduced the [Ca2+](i) signals. 4. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was reduced by 65% following pretreatment with 1 micromol/L thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete Ca2+ stored in the endoplasmic reticulum. 5. After pretreatment with 10 micromol/L fendiline in Ca2+-free medium for several minutes, addition of 3 mmol/L Ca2+ induced an increase in [Ca2+](i) of a magnitude four-fold greater than control. This increase in [Ca2+](i) was not reduced by 10 micromol/L SKF96365, econazole, nifedipine or verapamil. 6. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was not altered by inhibition of phospholipase C with 2 micromol/L 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino) hexyl)-1H-pyrrole-2,5-dione (U73122). 7. The results of the present study show that fendiline induces an increase in [Ca2+](i) in Chang liver cells by releasing stored Ca2+ in an inositol 1,4,5-trisphosphate-independent manner and by causing extracellular Ca2+ influx.
    Clinical and Experimental Pharmacology and Physiology 10/2001; 28(9):729-33. · 2.41 Impact Factor

Publication Stats

824 Citations
262.77 Total Impact Points

Institutions

  • 1996–2011
    • VGHKS Kaohsiung Veterans General Hospital
      • • Department of Surgery
      • • Department of Internal Medicine
      Kao-hsiung-shih, Kaohsiung, Taiwan
  • 2006
    • National Taiwan University
      • College of Medicine
      Taipei, Taipei, Taiwan
  • 2001–2006
    • Ping-Tung Christian Hospital
      P’ing-tung-chieh, Taiwan, Taiwan
    • Taipei Veterans General Hospital
      • Department of Medicine
      Taipei, Taipei, Taiwan
  • 2002
    • National Research Institute of Chinese Medicine
      T’ai-pei, Taipei, Taiwan
  • 2000–2001
    • Chang Gung Memorial Hospital
      • • Department of Orthopaedic Surgery
      • • Division of Neurology
      Taipei, Taipei, Taiwan
    • National Yang Ming University
      • Department of Surgery
      Taipei, Taipei, Taiwan
  • 1998–2001
    • National Sun Yat-sen University
      Kao-hsiung-shih, Kaohsiung, Taiwan