• Title/Summary/Keyword: Fura-2/AM

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The effect of octanol on the intracellular Ca2+ increase in submandibular acinar cells evoked by β-adrenergic activation (악하선 선포세포에서 β-아드레날린계 활성화 후 세포내 Ca2+ 농도 증가에 미치는 옥탄올의 효과)

  • Choi, Jeong-Iee
    • Journal of dental hygiene science
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    • v.2 no.1
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    • pp.47-51
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    • 2002
  • The concentration of intracellular $Ca^{2+}$ was measured by spectrofluorometer after rat submandibular acinar cells were loaded with fura-2/AM(fura-2). After isoproterenol and octanol were administered while letting submandibular gland acinar cell placed in a perfusion chamber flow through a standard solution, the changes of $Ca^{2+}$ concentration were measured. When they were administered separately, there showed little changes of intracellular $Ca^{2+}$ concentration. When they were administered at the same time, however the concentration of intracellar $Ca^{2+}$ was shown to increase. When forskolin, an adenylate cyclase activater, was administerd together with octanol the response looked similar to the response of isoproterenol. In case of the extracellular $Ca^{2+}$ was removed by omitting $Ca^{2+}$ in standard solution and treating EGTA, isoproterenol and forskolin does not affect to the concentration of intracellular $Ca^{2+}$. Therefore, it was certified that the increase of intracellular $Ca^{2+}$ was caused from outside the cell. In order to know that the $Ca^{2+}$ influx is related with capacitative entry pathway, godolinium, blocker of that pathway was treated. With the result of that experiment there was no complete control of the increase in the concentration of intracellular $Ca^{2+}$. However, speed and amount of $Ca^{2+}$ increase was comparatively diminished.

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Effects of Protein Kinases on Phospholipase C Activation and Intracellular $Ca^{2+}$ Mobilization Induced by Endothelin-1 (Endothelin-1에 의한 phospholipase C 활성화와 세포내 $Ca^{2+}$ 이동에 미치는 protein kinase들의 효과)

  • 조중형;김현준;이윤혜;박진형;장용운;이승준;이준한;윤정이;김창종
    • YAKHAK HOEJI
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    • v.44 no.2
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    • pp.162-168
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    • 2000
  • To investigate the effects of protein kinases on endothelin-1-induced phospholipase C activation and $Ca^{2+}$ mobilization in Rat-2 fibroblast, we measured the formation of inositol phosphates and intracellular $Ca^{2+}$ concentration with [$^3$H]inositol and Fura-2/AM, respectively. Endothelin-1 dose-dependently activated phospholipase C and increased intracellular $Ca^{2+}$ concentration. Protein kinase C activator PMA, significantly inhibited both phospholipase C activity and $Ca^{2+}$ mobilization induced by endothelin-1. Tyrosine kinase inhibitor, genistein, inhibited both. On the other hand, cyclic nucleotide (cAMP and cGMP) did not have any influence on the signaling pathway of phospholipase C-Ca$^{2+}$ mobilization induced by endothelin-1. These results suggest that protein kinase C and tyrosine kinase counteract on the signaling pathway of phospholipase C-Ca$^{2+}$ mobilization induced by endothelin-1 in Rat-2 fibroblast. fibroblast.

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Role of Calcium and Calcium Channels in Progesterone Induced Acrosome Reaction in Caprine Spermatozoa

  • Somanath, P.R.;Gandhi, K.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.7
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    • pp.949-956
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    • 2002
  • There are several physiological and pharmacological evidences indicating that opening of voltage dependent $Ca^{2+}$ channels play a critical role in induction of acrosome reaction in mammalian sperm. We determined the intracellular free $Ca^{2+}$ concentration in ejaculated goat sperm using a fluorescent, $Ca^{2+}$-specific probe, Fura2/AM, after the suspension of sperm in KRB medium, capable of sustaining capacitation and the acrosome reaction. We used nifedipine, D-600 and diltiazem, the $Ca^{2+}$ channel antagonists belonging to the classes of dihydropyridines, phenylalkylamines and benzothiazepines, to investigate the possibility that L-type voltage gated $Ca^{2+}$ channels play a role in the progesterone-stimulated exocytotic response. Progesterone promoted a rise in intracellular $Ca^{2+}$ in goat sperm and addition of nifedipine (100 nM) just prior to progesterone induction, significantly inhibited both intracellular $Ca^{2+}$ rise and exocytosis suggesting that $Ca^{2+}$ channels are involved in the process. However, the intracellular $Ca^{2+}$ increase during the process of capacitation was not affected with the addition of nifedipine suggesting a role of focal channel for $Ca^{2+}$ during capacitation. Studies using monensin and nigericin, two monovalent cation ionophores showed that an influx of $Na^+$ also may play a role in the opening of $Ca^{2+}$ channels. These results strongly suggests that the entry of $Ca^{2+}$ channels with characteristics similar to those of L-type, voltage-sensitive $Ca^{2+}$ channels found in cardiac and skeletal muscle, is a crucial step in the sequence of events leading to progesterone induced acrosome reaction in goat sperm.

Effect of Intracellular Calcium Level on the Hybridoma Cell Growth and Monoclonal Antibody Production (세포내 calcuim 농도가 하이브리도마 세포 성장 및 단일클론항체 생산에 미치는 영향)

  • 박재성;남민희;박선호
    • KSBB Journal
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    • v.13 no.5
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    • pp.585-592
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    • 1998
  • The effect of intracellular Ca2+ level on the hybridoma cell growth and monoclonal antibody(MAb) production was examined. For the manipulation of intracellular Ca2+ concentration, the cells were treated with A23187, ryanodine, and thapsigargin at about 1x106 cells/mL. The treated cells were recultivated by using the Iscove's Modified Dulbecco's Medium(MDM) containing 1.49mM CaCl2. The ryanodine-treated cells showed better cell growth, MAb concentration, and specific MAb productivity than others. In comparison with control, the maximum cell concentration, MAb concentration, and specific MAb productivity were increased by 40.6%, 48.1% and 83.3%, respectively. Confocal microscopic images of Fura-2/AM loaded cells indicate that the increase in intracellular Ca2+ level can enhance the MAb productivity by allowing the calcium influx into the endoplasmic reticulumn.

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Effects of Ginsenosides on the Glutamate Release and Intracellular Calcium Levels in Cultured Rat Cerabeller Neuronal Cells

  • Oh, Seikwan;Kim, Hack-Seang;Seong, Yeon-Hee
    • Archives of Pharmacal Research
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    • v.18 no.5
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    • pp.295-300
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    • 1995
  • These studies were designed to examine the effects of ginsenosides on glutamate neurotansmission. In primary cultures of rat cerebellar granule cells, ginsenosides (Rb1, Rc did not Rg1, $500\mug/ml$) increased glutamate release which was measured by HPLC. but HPLC, but Re did not shwo an elevation of glutamate release. However, all of these ginsenosides down-regulated N-methyl-D-aspartate (NMDA)-induced glutamate release. Rc strongly increased glutamate release and elevated intracellular clcium concentrations $([Ca_{2+}]_i)$ which was measured by ratio fluorometry with FURA-2AM. These results indicate that ginsenosides have a homeostatic effect on glutamate neurotransmission, and there is a structure-function relationship among the ginsenosides tested.

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Activation of acetylcholine receptor elicits intracellular Ca2+ mobilization, transient cytotoxicity, and induction of RANKL expression

  • Heo, Seong-Jong;Kim, Min Seuk
    • International Journal of Oral Biology
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    • v.41 no.3
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    • pp.119-123
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    • 2016
  • Acetylcholine receptors (AChR) including muscarinic and nicotinic AChR are widely expressed and mediate a variety of physiological cellular responses in neuronal and non-neuronal cells. Notably, a functional cholinergic system exists in oral epithelial cells, and nicotinic AChR (nAChR) mediates cholinergic anti-inflammatory responses. However, the pathophysiological roles of AChR in periodontitis are unclear. Here, we show that activation of AChR elicits increased cytosolic $Ca^{2+}([Ca^{2+}]_i)$, transient cytotoxicity, and induction of receptor activator of nuclear factor kappa-B ligand (RANKL) expression. Intracellular $Ca^{2+}$ mobilization in human gingival fibroblast-1 (hGF-1) cells was measured using the fluorescent $Ca^{2+}$ indicator, fura-2/AM. Cytotoxicity and induction of gene expression were evaluated by measuring the release of glucose-6-phosphate dehydrogenase and RT-PCR. Activation of AChR in hGF-1 cells by carbachol (Cch) induced $[Ca^{2+}]_i$ increase in a dose-dependent manner. Treatment with a high concentration of Cch on hGF-1 cells caused transient cytotoxicity. Notably, treatment of hGF-1 cells with Cch resulted in upregulated RANKL expression. The findings may indicate potential roles of AChR in gingival fibroblast cells in bone remodeling.

Myristicae Semen Extract Protects Excitotoxicity in Cultured Neuronal Cells

  • Kim, Ji-Ye;Ban, Ju-Yeon;Bang, Kyong-Hwan;Seong, Nak-Sul;Song, Kyung-Sik;Bae, Ki-Whan;Seong, Yeon-Hee
    • Korean Journal of Medicinal Crop Science
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    • v.12 no.5
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    • pp.415-423
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    • 2004
  • Myristica fragrans seed from Myristica fragrans Houtt (Myristicaceae) has various pharmacological activities peripherally and centrally. The present study aims to investigate the effect of the methanol extract of Myristica fragrans seed (MF) on kainic acid (KA)-induced neurotoxicity in primary cultured rat cerebellar granule neuron. MF, over a concentration range of 0.05 to $5\;{\mu}g/ml$ inhibited KA $(500\;{\mu}M)-induced$ neuronal cell death, which was measured by trypan blue exclusion test and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. MF $(0.5\;{mu}g/ml)$ inhibited glutamate release into medium induced by KA $(500\;{\mu}M)$, which was measured by HPLC. Pretreatment of MF $(0.5\;{mu}g/ml)$ inhibited KA $(500\;{\mu}M)-induced$ elevation of cytosolic calcium concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that MF prevents KA-induced neuronal cell damage in vitro.

Purinergic Receptors Play Roles in Secretion of Rat von Ebner Salivary Gland

  • Kim, Sang-Hee;Cho, Young-Kyung;Chung, Ki-Myung;Kim, Kyung-Nyun
    • International Journal of Oral Biology
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    • v.31 no.4
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    • pp.141-148
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    • 2006
  • The effects of adenosine triphosphate(ATP) on salivary glands have been recognized since 1982. The presence of purinergic recepetors(P2Rs) that mediate the effects of ATP in various tissues, including parotid and submandibular salivary gland, has been supported by the cloning of receptor cDNAs and the expression of the receptor proteins. P2Rs have many subtypes, and the activation of these receptor subtypes increase intracellular $Ca^{2+}$, a key ion in the regulation of the secretion in the salivary gland. The apical pores of taste buds in circumvallate and foliate papillae are surrounded by the saliva from von Ebner salivary gland(vEG). Thus, it is important how the secretion of vEG is controlled. This study was designed to elucidate the roles of P2Rs on salivary secretion of vEG. Male Sprague-Dawley rats (about 200 g) were used for this experiment. vEG-rich tissues were obtained from dissecting $500-1,000\;{\mu}m$ thick posterior tongue slices under stereomicroscope view. P2Rs mRNA in vEG acinar cells were identified with RT-PCR. To observe the change in intracellular $Ca^{2+}$ activity, we employed $Ca^{2+}-ion$ specific fluorescence analysis with fura-2. Single acinar cells and cell clusters were isolated by a sequential trypsin/collagenase treatment and were loaded with $10\;{\mu}M$ fura -2 AM for 60 minutes at room temperature. Several agonists and antagonists were used to test a receptor specificity. RT-PCR revealed that the mRNAs of $P2X_4$, $P2Y_1$, $P2Y_2$ and $P2Y_3$ are expressed in vEG acinar cells. The intracellular calcium activity was increased in response to $10\;{\mu}M$ ATP, a P2Rs agonist, and 2-MeSATP, a $P2Y_1$ and $P2Y_2R$ agonist. However, $300\;{\mu}M\;{\alpha}{\beta}-MeATP$, a $P2X_1$ and $P2X_3R$ agonist, did not elicit the response. The responses elicited by $10\;{\mu}M$ ATP and UTP, a $P2Y_2R$ agonists, were maintained when extracellular calcium was removed. $10\;{\mu}M$ suramin, a P2XR antagonist, and reactive blue 2, a P2YR antagonist, partially blocked ATP-induced response. However, when extracellular calciums were removed, suramin did not abolish the responses elicited by ATP. These results suggest that P2Rs play an important role in salivary secretion of vEG acinar cells and the effects of ATP on vEG salivary secretion may be mediated by $P2X_4$, $P2Y_1$, $P2Y_2$, and/or $P2Y_3$.

Compound K induced apoptosis via endoplasmic reticulum Ca2+ release through ryanodine receptor in human lung cancer cells

  • Shin, Dong-Hyun;Leem, Dong-Gyu;Shin, Ji-Sun;Kim, Joo-Il;Kim, Kyung-Tack;Choi, Sang Yoon;Lee, Myung-Hee;Choi, Jung-Hye;Lee, Kyung-Tae
    • Journal of Ginseng Research
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    • v.42 no.2
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    • pp.165-174
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    • 2018
  • Background: Extended endoplasmic reticulum (ER) stress may initiate apoptotic pathways in cancer cells, and ER stress has been reported to possibly increase tumor death in cancer therapy. We previously reported that caspase-8 played an important role in compound K-induced apoptosis via activation of caspase-3 directly or indirectly through Bid cleavage, cytochrome c release, and caspase-9 activation in HL-60 human leukemia cells. The mechanisms leading to apoptosis in A549 and SK-MES-1 human lung cancer cells and the role of ER stress have not yet been understood. Methods: The apoptotic effects of compound K were analyzed using flow cytometry, and the changes in protein levels were determined using Western blot analysis. The intracellular calcium levels were monitored by staining with Fura-2/AM and Fluo-3/AM. Results: Compound K-induced ER stress was confirmed through increased phosphorylation of $eIF2{\alpha}$ and protein levels of GRP78/BiP, XBP-1S, and $IRE1{\alpha}$ in human lung cancer cells. Moreover, compound-K led to the accumulation of intracellular calcium and an increase in m-calpain activities that were both significantly inhibited by pretreatment either with BAPTA-AM (an intracellular $Ca^{2+}$ chelator) or dantrolene (an RyR channel antagonist). These results were correlated with the outcome that compound K induced ER stress-related apoptosis through caspase-12, as z-ATAD-fmk (a specific inhibitor of caspase-12) partially ameliorated this effect. Interestingly, 4-PBA (ER stress inhibitor) dramatically improved the compound K-induced apoptosis. Conclusion: Cell survival and intracellular $Ca^{2+}$ homeostasis during ER stress in human lung cancer cells are important factors in the induction of the compound K-induced apoptotic pathway.