• 한국동물학회지
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• 제32권1호
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• pp.40-47
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• 1989

계배 근원세포의 배양 배지에 calcium ionophore A23187이나 EGTA를 배양 24시간에 첨가함으로서 초래된 세포내 칼슘 농도의 변화는 근원세포의 분화과정에 상당한 영향을 미쳤다. 배양 24시간에 A23187이나 EGTA를 첨가한 후 배양 48시간, 72시간, 및 96시간에 각각 세포를 [35S]methionine으로 1시간 표지시킨 후 수확하여 2차원 전기영동법으로 단백질을 분리시켰을 때, 일부 단백질은 배양 조건에 따라 합성 양상을 달리함을 보였다. 배양 24시간에 처리한 A23187과 calcium-activated neutral protease는 대조군에 비해 세포융합을 촉진시켰으나 동일 시기에 처리된 phosphoprotein을 정량함으로써 조사하였을 때, A23187이 배양 초기에는 대조군에 비해 약간 이 효소의 활성도를 높이는 효과를 보였으나 세포융합이 완성된 시기인 96시간에는 대조군에 비해 활성도를 높이는 효과를 보였으나 세포융합이 완성된 시기인 96시간에는 대조군에 비해 활성도의 차이를 나타내지 않았다. A23187 및 calcium-activated neutral protease에 의한 세포융합의 촉진, 그리고 A23187에 의한 protein kinase C 활성도의 증가가 모두 근원세포의 융합이 활발히 진행되는 시기인 배양 48-72 시간에 관찰됨을 볼 때, 세포내 칼슘의 농도는 protein kinase C 및 calcium-activated neutral protease와 상호연관을 가지면서 세포분화에 관여하는 것으로 사료된다.

• Molecular & Cellular Toxicology
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• 제4권1호
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• pp.16-21
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• 2008

Cell death of trophoblast, particularly by abnormal release of physiological nitric oxide (NO) has been known to be a causative factor of pre-eclampsia. In the present study, effects of intracellular calcium increase enhancing the activity of NO synthases (neuronal NO synthase, nNOS in this trophoblast cells) on the cell death were examined in a human placental full-term cell line (HT-1). Furthermore, we analyzed the possible mechanisms underlying the augmentation of $Ca^{++}$-mediated NOS activity mediated by protein kinases like PKC, PKA, or CaM-KII. In experiments for cell toxicity, a calcium ionophore (ionomycin $10{\mu}M$) enhanced cell death confirmed by MTT assay, and increased significantly nNOS activity determined with a hemoglobin oxidation assay. This cell death was partially protected by pre-treatment of 7-nitroindazole (7-NI, $10{\mu}M$ and $100{\mu}M$), a nNOS-specific inhibitor. Additionally, $Ca^{++}$-ionophore -induced increase of nNOS activity also was partially normalized by pre-treatment of specific inhibitors of protein kinases, PKC, PKA or CaM-KII. Therefore, we suggest that an increase of calcium influx, leading to the activation of nNOS activity, which in turn may result in the death of trophoblast cells by involvement of signaling mechanisms of protein kinases.

• Clinical and Experimental Reproductive Medicine
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• 제19권2호
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• pp.105-116
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• 1992

The present study was examined to clarify the role of calcium ion as a factor for the maturation of mouse oocytes. Follicles and cumulus-enclosed oocytes were isolated with two sharp needles under a stereomicroscope from female mouse (ICR) ovaries which were treated PMSG 5 IU 45-46 hours previously. Isolated follicles and cumulus-enclosed oocytes were cultured for 14-16 hours in an organ culture system at $37^{\circ}C$, 5% $CO_2$ in air and 100% humudified in incubator. MHBS was the basic medium used from which A23187, verapamil, $NiCl_{2.}$ $6H_2O$ and $LaCl_{3.}$ $7H_2O$ were added depending on the experimental groups. In follicle- or cumulus-enclosed oocytes wre cultured in these differently treated media. Following results were obtained from the present study. 1. The calcium ionophore A23187 directly or indirectly seems to stimulate GVBD of follicle-enclosed mouse oocytes. Increasing concentration of ionophore A23187 1ed to an increase in oocytes degeneration from the cumulus-enclosed mouse oocytes. 2. The organic $Ca^{++}$ channel blocker, verapamil does not induce GVBD of follicle-enclosed mouse oocytes. Specially, higher dose of 1 mM verapamil induced GVBD of follicle-enclosed mouse oocytes. However, cytoplasm of GVBD oocytes in 1 mM verapamil treated groups appeared shrunk. In the cumulus-enclosed oocytes, polar body formation was reduced in verapamil treated groups and degeneration increased. Verapamil inhibit oocyte maturation (polar body formation). 3. The $Ca^{++}$ inhibitor, Nickel ($NiCl_{2.}$ $6H_2O$) inhibits maturation of the follicle-enclosed oocytes. In the cumulus-enclosed oocytes the progression to MII (PB formation) was reduced and degeneration of mouse oocytes increased as the concentration of $Ni^{++}$ increase. The results indicates that nickel act as an inhibitor of calcium. 4. The $Ca^{++}$ inhibitors, Lanthanum ($LaCl_{3.}$ $7H_2O$) has shown different effect from that of nickel. In follicle-enclosed oocytes, 0.01mM lanthanum induced maturation of mouse oocytes. Polar body formation was reduced in the cumulus-enclosed oocytes all lanthanum treated group.

• 생명과학회지
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• 제17권2호통권82호
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• pp.174-178
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• 2007

malformin A1은 옥수수 뿌리에서 대조구와 비교하여 에틸렌 생성을 4시간에는 130%, 8시간에는 56%를 각각 촉진하였다. 에틸렌 생성량이 4시간을 최대로 하여 8시간까지 서서히 증가율이 감소하였다. 칼슘 이온 조절제인 A23187 (calcium ionophore)과 verapamil (calcium channel blocker)을 각각 단독으로 처리한 경우 모두 대조구와 비교하여 4시간에는 30%, 8시간에는 20% 정도로 에틸렌 생성을 촉진하였다. 칼슘 이온 조절제가 malformin A1에 의해 유도된 에틸렌 생성에 미치는 영향을 조사한 결과 4시간에는 malformin A1만 처리하였을 경우에 관찰되는 수준만큼 촉진되지 않았지만 칼슘 이온 조절제의 촉진 효과는 8시간까지 유지되었다. 이러한 결과는 malformin A1이 에틸렌 생성을 촉진하기 위하여 적절한 칼슘 농도가 필요할 가능성을 제시하고 있다. Malformin A1은 굴중성 굴곡 반응을 대조구와 비교하여 4시간과 8시간에 각각 58%와 42% 정도 억제하였다. A23187과 달리, verapamil은 굴중성 굴곡반응을 4시간과 8시간에 대조구와 비교하여 각각 54%와 23%를 억제하였다. 더 나아가 verapamil은 malformin A1에 의해 유도된 굴중성 굴곡 반응을 A23187보다 더 억제하였다. 이러한 결과는 칼슘이온 조절제가 malformin A1에 의해 유도된 옥수수 뿌리의 굴중성 반응에 영향을 주며, 칼슘 이온이 굴중성 반응에 중요한 역할을 한다는 증거를 제시한다.

• Bulletin of the Korean Chemical Society
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• 제27권6호
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• pp.835-840
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• 2006

Dimethyl 1-(4-nitrobenzoyl)-8-oxo-2,8-dihydro-1H-pyrazolo[5,1-a]isoindole-2,3-dicarboxylate has been used as an ionophore and o-nitrophenyloctyl ether as a plasticizer in order to develop a poly(vinyl chloride)-based membrane electrode for calcium ion detection. The sensors exhibit significantly enhanced response towards calcium(II) ions over the concentration range $8.0{\times}10^{-7}\;1.0{\times}10^{-1}$ M at pH 3.0-11 with a lower detection limit of $5.0 {\times}10^{-7}$ M. The sensors display Nernstian slope of 29.5 ${\pm}$ 0.5 mV per decade for Ca(II) ions. Effects of plasticizers, lipophilic salts and various foreign common ions are tested. It has a fast response time within 10 s over the entire concentration range and can be used for at least 2 months without any divergence in potentials. The proposed electrode revealed good selectivity and response for $Ca^{2+}$ over a wide variety of other metal ions. The selectivity of the sensor is comparable with those reported for other such electrodes. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a Ca(II) solution, with EDTA.

• Journal of Ginseng Research
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• 제40권3호
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• pp.251-259
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• 2016

Background: Estrogen signaling pathways are modulated by exogenous factors. Panax ginseng exerts multiple activities in biological systems and is classified as an adaptogen. Zearalenol is a potent mycoestrogen that may be present in herbs and crops arising from contamination or endophytic association. The goal of this study was to investigate the impact of P. ginseng, zearalenol and estradiol in tests on spermatozoal function. Methods: The affinity of these compounds for estrogen receptor (ER)-alpha and beta ($ER{\alpha}$ and $ER{\beta}$)-was assessed in receptor binding assays. Functional tests on boar spermatozoa motility, movement and kinematic parameters were conducted using a computer-assisted sperm analyzer. Tests for capacitation, acrosome reaction (AR), and chromatin decondensation in spermatozoa were performed using microscopic analysis. Results: Zearalenol-but not estradiol ($E_2$)- or ginseng-treated spermatozoa-decreased the percentage of overall, progressive, and rapid motile cells. Zearalenol also decreased spontaneous AR and increased chromatin decondensation. Ginseng decreased chromatin decondensation in response to calcium ionophore and decreased AR in response to progesterone ($P_4$) and ionophore. Conclusion: Zearalenol has adverse effects on sperm motility and function by targeting multiple signaling cascades, including $P_4$, $E_2$, and calcium pathways. Ginseng protects against chromatin damage and thus may be beneficial to reproductive fitness.

• 한국식품영양과학회지
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• 제43권3호
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• pp.349-354
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• 2014

세포내 $Ca^{{+}{+}}$의 증가는 비만세포에서 수용체 활성을 거치지 않고 탈과립을 유도한다. 괴화는 천연 염색 재료로 사용되고 있으며, 또한 항염증 작용과 $Fc{\varepsilon}RI$와 IgE 가교에 의한 항알레르기 효능도 보고되었다. 이번 연구에서 비만세포에서 $Ca^{{+}{+}}$ 유입에 의해 생산되는 알레르기 매개물에 대한 괴화 추출물의 조절 기능을 보고한다. 괴화 추출물은 A23187에 의해 유도되는 IL-4와 TNF-${\alpha}$의 생산과 탈과립을 저해하였다. 또한 괴화 추출물은 DNFB로 유도한 알레르기 피부염의 동물 모델에서 알레르기 반응을 억제하였다. 괴화추출물 50 mg/kg을 경구투여 또는 도말을 한 경우, DNFB를 단독으로 처리한 군보다 IL-4, TNF 그리고 IFN-${\gamma}$와 같은 염증성 사이토카인의 생산량이 감소하였다. 또한 괴화 추출물을 처리한 경우 혈청 내 IgE의 함량이 DNFB를 단독으로 처리한 군보다 감소하였다. 괴화 추출물을 처리한 군에서의 비장과 림프절의 무게도 DNFB를 단독으로 처리한 군보다 감소하였다. 이러한 결과를 토대로 괴화는 비만세포에서 $Fc{\varepsilon}RI$ 자극뿐만 아니라 $Ca^{{+}{+}}$의 유입에 의한 항알레르기 효능이 있다는 것을 보고한다.

• Journal of Plant Biology
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• 제39권2호
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• pp.113-121
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• 1996

The role of Ca2+ on benzyladenine (BA)-induced senescence retardation in mature wheat (Triticum aestivum L.) primary leaves was investigated. When an extracellular calcium chelator, ethylene glycol-bis-($\beta$-aminoethylether)-N, N'-tetraacetic acid (EGTA) together with BA, was applied to senescing leaves for 4 days of dark incubation, the content of chlorophyll and soluble protein decreased rapidly. And, the content of malondialdehyde (MDA), known to be a degradation product of membrane lipids, increased compared with the BA alone control. The BA-EGTA combination also caused the stimulation of protease and RNase activity and a rapid loss of catalase activity owing to the decling of BA effects. In the case of treatment with only intracellular calcium antagonist 3, 4, 5-trimethoxybenzoic acid 8-(diethylamino) octyl ester (TMB-8) without the BA addition, the chlorophyll content at day 4 after dark incubation decreased in paralled with the increasing concentration of the antagonist. In addition, the chlorophyll content at 10-5 M calcium ionophore A23187 treatment in the absence of BA was similar to that of the BA alone treatment. These results suggest that calcium may mediate the retardation effect of BA on leaf senescence by acting as a second messenger and that the calcium input from cell organelles, as well as the calcium inflow from intercellular spaces and cell walls, may be involved in modulating cytosolic calcium levels related to BA action.

• BMB Reports
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• 제31권5호
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• pp.468-474
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• 1998

Membrane depolarization in PC12 cells induces calcium influx via an L-type voltage-sensitive calcium channel (L-VSCC) and increases intracellular free calcium, which leads to tyrosine phosphorylation of epidermal growth factor (EGF) receptor and the associated adaptor protein, She. This activated EGF receptor complex then can activate mitogen-activated protein (MAP) kinase, as in nerve growth factor (NGF) receptor activation. In the present study, we investigated the role of EGF receptor in the signaling pathway initiated by membrane depolarization of PC12 cells. Prolonged membrane depolarization induced phosphorylation of extracellular signal-regulated kinase (ERK) within 1 min in undifferentiated PC12 cells. Pretreatment of PC12 cells with the calcium chelator EGTA abolished depolarization-stimulated ERK phosphorylation, but NGF-induced phosphorylation of ERK was not affected. The chronic treatment of phorbol ester, which down-regulated the activity of protein kinase C (PKC), did not affect the phosphorylation of ERK upon depolarization. In the presence of an inhibitor of EGF receptor, neither depolarization nor calcium ionophore increased the level of ERK phosphorylation. These data imply that the EGF receptor is functionally necessary to activate ERK and neurite outgrowth in response to the prolonged depolarization in PC12 cells, and also that PKC is apparently not involved in this signaling pathway.

• 한국동물학회지
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• 제36권4호
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• pp.487-495
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• 1993

TRH (Thvrotropin-Releasing Hormone) known to regulate the transcription of the TSH (Thyroid-Stimulating Hormones gene in pituitary cells, but little is understood about the mechanism(sl involved. re present study was attempted to elucidate the role of Ca2+ movement through the voltage-gated channels in the regulation of TSH gene transcription. The c-fos is one of immediate early genes and used as model system for the investigation of signaling pathwavs involved in various stimuli. The changes of c-fos mRNA levels were determined after treatment of various agents using Northern and slot hybridization analysis. The c-fos mRNA was rapidly and transiently induced by TRH (about 3-fold) in GH3 cells and this induction was repressed by calcium chelating agent (EGTA), calcium channel blocker (verapamil) anti protein kinase C inhibitor (aminoacridine). The abilities of forskolin (adenvlate cvclase activators, PMA (protein kinase C activator), and A23187 (calcium ionophore) to affect c-ios gene transcription, either alone or in combination with TRH were tested in the same cells. All of them significantly increased the level of c-fos mRUA. However, no additive relationship was observed in all combined treatments except forskolin. These results suggest that TRH action on the c-fos gene activation is mediated by calcium influx as well as through protein kinase C.