• Biomolecules & Therapeutics
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• 제25권2호
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• pp.194-201
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• 2017

Lysophosphatidylethanolamine (LPE), a lyso-type metabolite of phosphatidylethanolamine, has been reported to be an intercellular signaling molecule. LPE mobilizes intracellular $Ca^{2+}$ through G-protein-coupled receptor (GPCR) in some cells types. However, GPCRs for lysophosphatidic acid (LPA) were not implicated in the LPE-mediated activities in LPA GPCR overexpression systems or in SK-OV3 ovarian cancer cells. In the present study, in human SH-SY5Y neuroblastoma cells, experiments with $LPA_1$ antagonists showed LPE induced intracellular $Ca^{2+}$ increases in an $LPA_1$ GPCR-dependent manner. Furthermore, LPE increased intracellular $Ca^{2+}$ through pertussis-sensitive G proteins, edelfosine-sensitive-phospholipase C, 2-APB-sensitive $IP_3$ receptors, $Ca^{2+}$ release from intracellular $Ca^{2+}$ stores, and subsequent $Ca^{2+}$ influx across plasma membranes, and LPA acted on $LPA_1$ and $LPA_2$ receptors to induce $Ca^{2+}$ response in a 2-APB-sensitive and insensitive manner. These findings suggest novel involvements for LPE and LPA in calcium signaling in human SH-SY5Y neuroblastoma cells.

• 대한본초학회지
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• 제30권6호
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• pp.25-32
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• 2015

Objectives : The purpose of this study was to investigate the endothelium-dependent vasorelaxation effect of Cynomorii Herba(CH) extract on contracted rabbit carotid artery.Methods : To clarify the vasorelaxation effect of CH extract, arterial strips with intact was used, to endothelium -dependent vasorelaxation effect of CH extract, arterial strips damaged endothelium was used for experiment using organ bath. Arterial strips was contracted with phenylephrine(PE) before treated with CH extract(0.01, 0.03 and 0.1 ㎎/㎖). To study mechanisms of CH-induced vasorelaxation effect, CH extract infused into arterial rings after treatment by indomethacin(IM), tetraethylammonium chloride(TEA), Nω-nitro-L-arginine (L-NNA), methylene blue(MB) for comparing with non-treated. And calcium chloride(Ca²⁺) 1 mM was treated into precontracted arterial ring induced by PE after treatment of CH extract in Ca²⁺-free krebs solution. Cytotoxic activity of CH extract on human umbilical vein endothelial cell(HUVEC) was measured by MTT assay, and nitric oxide(NO) concentration was measured by Griess reagent.Results : PE-induced arterial strips was significantly relaxed, but the damaged endothelium arterial ring wasn't relaxed by CH extract. Pretreatment of IM, TEA didn't inhibit the vasorelaxation of CH extract, but pretreatment of L-NNA, MB inhibited the vasorelaxation of CH extract. Pretreatment of CH extract reduced the increase of contraction by influx of extracellular Ca²⁺ in contracted arterial ring induced by PE, CH extract increased nitric oxide concentration on HUVEC significantly.Conclusions : This study shows that CH extract have the vasorelaxation effect by blocking the influx of extracellular Ca²⁺ through the activating NO-cGMP system.

• Journal of Ginseng Research
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• 제24권4호
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• pp.196-201
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• 2000

흰쥐 소뇌로부터 과립신경세포를 배양하여 NaCN으로 유도되는 신경세포손상에 대한 ginsenosides의 보호효과를 검토하였다. NaCN(I~10 M)을 배양된 세포에 1시간 동안 처리하면 농도 의존적으로 신경세포사를 일으켰다. Ginsenosides(Rb$_1$, Rc, Re, Ri, Rg$_1$)(0.5, 5 $\mu\textrm{g}$/ml를 세포에 전처치하면 10 mM NaCN으로 유도되는 세포사가 현저히 감소되었다. Rb$_1$과 Rc(5$\mu\textrm{g}$/ml)는 5 mM NaCN에 의하여 배양액 중으로 유리되는 glutamate의 증가를 현저히 억제하였으며, 1 mM N3CN에 의하여 유발되는 세포내 $Ca^{2+}$농도의 증가를 억제하였다. NaCN으로 유발되는 세포독성은 또한 MK-801, verapamil, NAME에 의하여도 억제되었다. 따라서, NaCN으로 유도되는 신경세포사는 glutamate release를 통한 NMDA수용체의 활성화와 그에 따른 $Ca^{2+}$의 세포내유입에 의한 것임을 알수 있고, ginsenosides, 특히 Rb$_1$과 Rc는 $Ca^{2+}$의 유입을 억제하므로서 NaCN에 의한 신경세포사를 억제하는 것으로 생각된다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.54-54
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• 2003

Prostate gland contains neuroendocrine cells (PNECs) are playing important roles in physiological and pathophysiological processes of the prostate gland. Here, we investigated the role of purinoceptors in PNECs freshly isolated from rat ventral prostate (RPNECs) that show immunoreactivity to chromogranin A. Fura-2 ratiometry revealed that ATP evokes both fast Ca$\^$2+/ influx and store Ca$\^$2+/ release in RPNECs. A whole-cell patch clamp study demonstrated fast inactivating cationic current activated by ATP or by ${\alpha}$,${\beta}$-MeATP, which was blocked by ATP-TNP. The activation of P2X inward current was tightly associated with a sharp increase in [Ca$\^$2+/]$\sub$c/. The presence of P2X1/3 subtypes were proved by RT-PCR analysis. For the stored Ca$\^$2+/ release, ATP and UTP showed similar effects, suggesting the dominant role or P2Y2 subtypes, also confirmed by RT-PCR. Both P2X (${\alpha}$,${\beta}$-MeATP) and P2Y (UTP) stimulation induced changes in the cell morphology (initial shrinkage and blob formation on the surface) reversibly. Exocytotic membrane trafficking events were monitored with the membrane-bound fluorescent dye, FM1-43 using confocal microscopy. In spite of the similar Ca$\^$2+/ responses, UTP was far less effective in triggering exocytosis than ${\alpha}$,${\beta}$ -MeATP. Since serotonin is reportedly stored in the secretory granule of PNECs, we directly examined whether the aforementioned agonists elicit release of serotonin using carbon fiber electrode-amperometry. In accordance with the results of FM1 -43 experiments, ${\alpha}$,${\beta}$-MeATP efficiently evoke serotonin secretion while not with UTP. In summary, the P2X-mediated Ca$\^$2+/ influx plays crucial roles in the exocytosis of RPNECs. Although a global increase in [Ca$\^$2+]$\sub$c/ might be related with the morphological changes, a sharp rise of [Ca$\^$2+/]$\sub$c/ in the putative sub-plasmalemmal ‘microdomains’ might be a decisive factor for the exocytosis.

• Clinical and Experimental Reproductive Medicine
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• 제25권3호
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• pp.269-275
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• 1998

It has been reported that the $Ca^{2+}$-ATPase and the $Ca^{2+}-Na^+$ exchanger play an important role for the regulation of intracellular $Ca^{2+}$ in somatic cells, the $Ca^{2+}$-ATPase located in the plasma membrane helps the $Ca^{2+}$ concentration in maintain low $[Ca^{2+}]_i$. Roldan & Fleming reported that the spermatozoan $Ca^{2+}$-ATPase plays an important role in the capacitation and acrosome reaction. We used to assess $Ca^{2+}$ changes by chlortetracycline (CTC) patterns in the capacitation and acrosome reaction of human and hamster spermatozoa. In the present study applying quercetin which has been known as an ATPase antagonist, the enzymatic effect of $Ca^{2+}$-ATPase on capacitation and acrosome reaction was found to be remarkable: a significant increase of the transformation from the original type to the B type and the AR type of spermatozoa. This finding suggests that $Ca^{2+}$-ATPase play an important role in the efflux and the influx of the $Ca^{2+}$ which have been known to be an essential factor for the capacitation and acrosome reaction, and that the inhibitory action of the $Ca^{2+}$-ATPase might be a prerequsit step toward the capacitation and acrosome reaction. In conclusion, this study suggest the considerable evidence as follows: the increment of the intracellular $Ca^{2+}$ concentration occurred by controlling the slope of $Ca^{2+}$ concentration through $Ca^{2+}$-ATPase activites in both the intracellular and extracellulr fluid may be important procedures for the capacitation and the acrosome reaction, and finally for fertilization of the sperm and ovum.

• Journal of Microbiology
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• 제34권3호
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• pp.263-263
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• 1996

Infection of fish cells with IHNV resulted in gradual increase in cytosolic free $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ in CHSE, gradual decrease in $[Ca^{2+}]_i$ in FHM, and no significant change in RTG cells. The degree of $[Ca^{2+}]_i$ increase or decrease was dependent on the amount of infectious virus, and these $[Ca^{2+}]_i$ variations were maximal at 16 hours after virus infection (p. i.) in both cell lines. When the fish cells were infected with inactivated IHNV, evident variation in $[Ca^{2+}]_i$ was not observed. Thus, infectivity of IHNV appears to correlate with changes in $[Ca^{2+}]_i$ in virus-infected cells. These IHNV-induced $[Ca^{2+}]_i$ changes were partially blocked by cycloheximide, but not affected by cordycepin. It seems to be that virus-induced $Ca^{2+}$ variations were more related with protein synthesis than RNA synthesis. Various $Ca^{2+}$ related drugs were used in search for the mechanisms of the $[Ca^{2+}]_i$, changes following IHNV infection of CHSE cells. Decreasing extracellular $Ca^{2+}$ concentration or blocking $Ca^{2+}$ influx from extracellular media inhibited the IHNV-induced increase in $[Ca^{2+}]_i$, in CHSE cells. Similar results were obtained with intracellular $Ca^{2+}$ blockers. Thus it is suggested that both the extracellular and the intracellular $Ca^{2+}$ sources are important in IHNV-induced $[Ca^{2+}]_i$ increase in CHSE cells.

• 대한본초학회지
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• 제25권4호
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• pp.17-21
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• 2010

Objectives : The aim of this study was to evaluate the differential mechnism of vasodilation of alcohol steamed Rhei Tangutici Radix et Rhizoma. (ART) and Rhei Tangutici Radix et Rhizoma. (RT) in rat thoracic aorta. Methods : Rat aortic ring preparations were mounted in organ baths with oxygenated (95% $O_2$-5% $CO_2$) Krebs-Ringer bicarbonate solutions at $37{\pm}0.5^{\circ}C$ and subjected to contractions or relaxations. Results : ART exerted vasorelaxation on phenylephrine(PE)-induced contraction in a dose dependent manner. Vasorelaxation effects of ART and RT were endothelium-independent. In the $Ca^{2+}$-free high KCl (60 mM) baths, the contraction of aortic rings induced by accumulative addition of $Ca^{2+}$ (0.3-10.0 mM) was significantly reduced by pre-treatment with both ART and RT for 10 min. The magnitude of vasodilatation was biggerin ART. Moreover, verapamil ($0.001{\mu}M$) and diltiazem ($10{\mu}M$), voltage operative $Ca^{2+}$channel blockers, attenuated the relaxation effect of ART but not that of RT. In the absence of extracellular $Ca^{2+}$, pre-incubation of the aortic rings with RT ($1.0mg/m{\ell}$) significantly reduced the contraction caused by PE but not that of ART. $K^+$ channel inhibitors such as glibenclamide (Gli, $10^{-5}M$), tetraethylammonium (TEA, 1 mM) and 4-aminopyridine (4-AP, 0.2 mM) significantly reduced the ART's vasorelaxation efficacy, but not that of RT. However, the relaxation effects of ART and RT were not inhibited by pre-treatment with indomethacin ($10^{-5}M$), and atropine ($10^{-6}M$). Conclusions : These results suggest that the endothelium-independent relaxation is due to inhibition of $Ca^{2+}$ influx via the suppression of $Ca^{2+}$ release from intracelluar store in RT but via both voltage operative $Ca^{2+}$channel blockage and $K^+$ channel activation in ART.

• The Korean Journal of Physiology and Pharmacology
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• 제6권2호
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• pp.93-99
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• 2002

Effects of oxidized low-density lipoprotein (ox-LDL), $1-{\alpha}-stearoyl-lysophosphatidylcholine$ (LPC), on intracellular $Ca^{2+}$ concentration were examined in mouse endothelial cells by measuring intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ with fura 2-AM and reverse transcription-polymerase chain reaction (RT-PCR). LPC increased $[Ca^{2+}]_i$ under the condition of 1.5 mM $[Ca^{2+}]_o$ but did not show any effect under the nominally $Ca^{2+}-free$ condition. Even after the store depletion with $30{\mu}M$ 2,5-di-tert- butylhydroquinone (BHQ) or $30{\mu}M$ ATP, LPC could still increase the $[Ca^{2+}]_i$ under the condition of 1.5 mM $[Ca^{2+}]_o.$ The time required to increase [$Ca{2+}$]i (about 1 minute) was longer than that for ATP-induced $[Ca^{2+}]_i$ increase $(10{\sim}30\;seconds).$ LPC-induced $[Ca^{2+}]_i$ increase was completely blocked by $1{\mu}M\;La^{3+}.$ Transient receptor potential channel(trpc) 4 mRNA was detected with RT-PCR. From these results, we suggest that LPC increased $[Ca^{2+}]_i$ via the increase of $Ca^{2+}$ influx through the $Ca^{2+}$ routes which exist in the plasma membrane.

• The Korean Journal of Ecology
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• 제20권2호
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• pp.83-94
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• 1997

Stomatal closing by ozone and water stress could reduce further ozone injury by inhibition of ozone influx to the tissue. Direct effect of ozone on stomata can be explained from two aspects which are a stimulation of stomatal closing and an inhibition of stomatal opening. An increase of $Ca^{2+}$ influx into cytoplasm by ozone could stimulate potassium efflux ion channel and inhibits inward potassium ion channels. By this mechanism ozone could induce stomatal closing. On the other hand, ozone could inhibit stomatal opening by affecting the activity of $H^{+}$ dependent ATPase of the membrane in guard cells. This would inhibit proton efflux which precede stomatal opening. It is also possible that ozone could reduce the activity of photosynthesis in guard cells which lead to affect the production of osmotically active sugars and energy. Indirect effect of ozone to stomata is through the effect of $CO_2$ elevation as a result of damage of the photozynthetic machinery. This indirect effect is slower than the direct effect.

• The Korean Journal of Physiology and Pharmacology
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• 제18권3호
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• pp.241-247
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• 2014

To investigate the underlying mechanisms of C18 fatty acids (stearic acid, oleic acid, linoleic acid and ${\alpha}$-linolenic acid) on mast cells, we measured the effect of C18 fatty acids on intracellular $Ca^{2+}$ mobilization and histamine release in RBL-2H3 mast cells. Stearic acid rapidly increased initial peak of intracellular $Ca^{2+}$ mobilization, whereas linoleic acid and ${\alpha}$-linolenic acid gradually increased this mobilization. In the absence of extracellular $Ca^{2+}$, stearic acid ($100{\mu}M$) did not cause any increase of intracellular $Ca^{2+}$ mobilization. Both linoleic acid and ${\alpha}$-linolenic acid increased intracellular $Ca^{2+}$ mobilization, but the increase was smaller than that in the presence of extracellular $Ca^{2+}$. These results suggest that C18 fatty acid-induced intracellular $Ca^{2+}$ mobilization is mainly dependent on extracellular $Ca^{2+}$ influx. Verapamil dose-dependently inhibited stearic acid-induced intracellular $Ca^{2+}$ mobilization, but did not affect both linoleic acid- and ${\alpha}$-linolenic acid-induced intracellular $Ca^{2+}$ mobilization. These data suggest that the underlying mechanism of stearic acid, linoleic acid and ${\alpha}$-linolenic acid on intracellular $Ca^{2+}$ mobilization may differ. Linoleic acid and ${\alpha}$-linolenic acid significantly increased histamine release. Linoleic acid (C18:2: ${\omega}$-6)-induced intracellular $Ca^{2+}$ mobilization and histamine release were more prominent than ${\alpha}$-linolenic acid (C18:3: ${\omega}$-3). These data support the view that the intake of more ${\alpha}$-linolenic acid than linoleic acid is useful in preventing inflammation.