• 치위생과학회지
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• 제2권1호
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• pp.47-51
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• 2002

Sprague-Dawley계 흰쥐의 악하선에서 선세포를 분리하여 fura-2/AM(fura-2)으로 염색한 후 spectrofluorometer로 세포내 $Ca^{2+}$농도를 측정하였다. 악하선 세포를 관류장치(perfusion chamber)에 넣고 표준용액을 관류시키면서 isoproterenol($1{\mu}M$)과 octanol(1mM)을 투여한 후 $Ca^{2+}$농도 변화를 측정하였는데 단독 투여시 $Ca^{2+}$농도는 거의 변화하지 않았으나 함께 투여한 경우 세포 내 $Ca^{2+}$농도가 증가함을 확인할 수 있었다. Adenylate-cyclase를 활성화 시키는 forskolin($10{\mu}M$)과 octanol을 함께 투여하였을 때도 isoproterenol의 경우와 유사한 증가 현상을 보이는 것으로 볼 때 octanol과 isoproterenol 또는 forskolin이 함께 작용할 때 세포 내 $Ca^{2+}$가 증가하는 것을 확인할 수 있었다. $Ca^{2+}$의 증가기전을 확인하고자 표준용액의 $Ca^{2+}$를 제거함은 물론 EGTA를 처리하여 세포외부의 $Ca^{2+}$를 제거한 후 상기한 바와 동일한 실험을 반복한 결과 $Ca^{2+}$농도의 증가를 보이지 않았다. 따라서 세포 내 $Ca^{2+}$의 증가는 세포 외부로부터의 $Ca^{2+}$유입 때문인 것으로 확인할 수 있었다. 이러한 $Ca^{2+}$의 유입 capacitative entry pathway를 이용하는지 확인코자 gadolinium($10{\mu}M$)을 처리하였을 때 $Ca^{2+}$농도의 증가가 완전히 억제되지는 않았지만 $Ca^{2+}$의 증가속도와 증가량이 감소되어 있음을 확인할 수 있었다. 이상의 실험결과들을 정리하면 세포 내 $Ca^{2+}$농도의 증가와 관련 ${\beta}$-아드레날린계 관련 약물과 옥탄올(octanol)을 함께 처리할 경우 세포 내 $Ca^{2+}$는 세포 외부에서 유입되어 증가되고 그 경로는 일부 capacitative entry pathway를 통함을 확인할 수 있었다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1998년도 학술발표회
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• pp.30-30
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• 1998

The effects of capsaicin on phospholipase (PLC)-induced capacitative $Ca^{2＋}$ entry (CCE) were investigated in PC12 cells. Capsaicin inhibited one of PLC-linked signal, extracellular ATP-induced norepinephrine secretion with a concentration range, 10-100 $\mu$M. Capsaicin did not inhibit the peak portion of extracellular ATP-mediated [Ca$^{2＋}$]i rise, but it recovered more rapidly to the normal level of [Ca$^{2+}$]i from the sustained [Ca$^{2+}$]i level.(omitted)ted)

• Biomolecules & Therapeutics
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• 제32권3호
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• pp.301-308
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• 2024

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disorder characterized by extracellular amyloid plaques composed of amyloid β-peptide (Aβ). Studies have indicated that Ca²⁺ dysregulation is involved in AD pathology. It is reported that decreased capacitative Ca²⁺ entry (CCE), a refilling mechanism of intracellular Ca²⁺, resulting in increased Aβ production. In contrast, constitutive activation of CCE could decrease Aβ production. Panax ginseng Meyer is known to enhance memory and cognitive functions in healthy human subjects. We have previously reported that some ginsenosides decrease Aβ levels in cultured primary neurons and AD mouse model brains. However, mechanisms involved in the Aβ-lowering effect of ginsenosides remain unclear. In this study, we investigated the relationship between CCE and Aβ production by examining the effects of various ginsenosides on CCE levels. Aβ-lowering ginsenosides such as Rk1, Rg5, and Rg3 potentiated CCE. In contrast, ginsenosides without Aβ-lowering effects (Re and Rb2) failed to potentiate CCE. The potentiating effect of ginsenosides on CCE was inhibited by the presence of 2-aminoethoxydiphenyl borate (2APB), an inhibitor of CCE. 2APB alone increased Aβ42 production. Furthermore, the presence of 2APB prevented the effects of ginsenosides on Aβ42 production. Our results indicate that ginsenosides decrease Aβ production via potentiating CCE levels, confirming a close relationship between CCE levels and Aβ production. Since CCE levels are closely related to Aβ production, modulating CCE could be a novel target for AD therapeutics.

• Archives of Pharmacal Research
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• 제26권1호
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• pp.64-69
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• 2003

To analyze vasopressin-induced $Ca^{2+}$ increase in liver cells, rat hepatocytes were isolated and attached to collagen-coated cover slips. Using fura-2, a $Ca^{2+}$-sensing dye, changes in intracellular $Ca^{2+}$ concentration by vasopressin were monitored. Results in this communication suggested that vasopressin-induced $Ca^{2+}$ increase were composed of both $Ca^{2+}$ release from internal $Ca^{2+}$ stores and influx from the plasma membrane. The $Ca^{2+}$ influx consisted of two distinguishable components. One was dependent on the presence of vasopressin and the other was not. SK＆F96365 blocked vasopressin-induced $Ca^{2+}$ influx in a dose-dependent manner. Vasopressin-induced $Ca^{2+}$ release from internal stores diminished in a primary culture of hepatocytes according to the culture time. However, changes in vasopressin-induced $Ca^{2+}$ influx across the plasma membrane differed from changes in the $Ca^{2+}$ release from internal stores, suggesting two separate signalings from receptor activation to internal stores and to the plasma membrane.

• BMB Reports
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• 제33권3호
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• pp.202-207
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• 2000

The depletion of intracellular calcium stores by thapsigargin treatment evoked extracellular calcium-dependent membrane currents in Xenopus laevis oocytes. These currents have been compared to those evoked by microinjection of a calcium influx factor (CIF) purified from Jurkat T lymphocytes. The membrane currents elicited by thapsigargin treatment (peak current, $163{\pm}60$ nA) or CIF injection (peak current, $897{\pm}188$ nA) were both dependent on calcium entry, based on their eradication by the removal of extracellular calcium. The currents were, in both cases, attributed primarily to well-characterized $Ca^{2+}-dependent$ $Cl^-$ currents, based on their similar reversal potentials (-24 mV vs. -28 mV) and their inhibition by niflumic acid (a $Cl^-$ channel blocker). Currents induced by either thapsigargin treatment or CIF injection exhibited an identical pattern of inhibitory sensitivity to a panel of lanthanides, suggesting that thapsigargin treatment or CIF injection evoked $Cl^-$ currents by stimulating calcium influx through pharmacologically identical calcium channels. These results indicate that CIF acts on the same calcium entry pathway activated by the depletion of calcium stores and most lanthanides are novel pharmacological tools for the study of calcium entry in Xenopus oocytes.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.259-259
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• 2004

Porcine sperm extract (PSE) supporting Ca/sup 2+/ osillation was microinjected into the in vitro matured porcine oocytes. In the presence of the capacitative Ca/sup 2+/ entry mechanism which can activate MII oocytes, preparation methods of sperm extraction were studied by many researchers. Such as freeze-thaw cycle, homogenation, sonication of boar sperm was used for certification of their activity of calcium signals. (omitted)

• 생명과학회지
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• 제17권8호통권88호
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• pp.1053-1062
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• 2007

유방암 치료제로 사용되는 탐옥시펜 (Tam)은 MCF-7 세포주에서 세포증식을 억제하며 세포사멸을 유도한다. 본 연구에서는 Tam의 세포독성 효과가 세포 내 칼슘이온 농도 증가에 따른 미토콘드리아-의존 기작에 의하여 일어난다는 것을 보여준다. Tam에 의해 유도된 세포 내 칼슘이온 농도 증가는 주로 외부로부터의 칼슘 유입에 의한 것으로 생각된다. 칼슘 채널 억제제를 이용한 실험 결과에 의하며, 칼슘 증가 초기 단계는 주로 전압의존 칼슘채널에 의한 것이며 후기에는 세포 내 저장된 칼슘의 유출, 혹은 다른 방법에 의한 칼슘 유입으로 생각된다. Tam에 의한 세포 내 칼슘 증가는 미토콘드리아로부터의 cytochrome c 방출과 미토콘드리아막의 탈분극에 의한 membrane potential 변화를 초래하였다. 세포사멸에 주도적인 역할을 하는 caspase의 확인에 있어서는, MCF-7 세포는 caspase-3이 결핍되어서 caspase-7이 중심적인 역할을 하는 것으로 이미 알려져 있다. 본 연구에서 확인한 결과 Tam 처리시 caspase-7이 활성화되었으며, 또한 세포사멸 조절 단백질인 Bcl-2 종류 단백질들의 발현을 조사 한 결과 세포사멸 억제 단백질인 Bcl-2의 발현에는 변화가 없었으나 촉진단백질인 Bax는 Tam 처리시 단백질 양이 2배로 증가되었다. 이상의 결과에 의하면, Tam에 의해 유도되는 세포사멸과정은 세포질 내 칼슘이온 농도증가에 의한 미토콘드리아의 변화가 주도적인 역할을 하는 것으로 생각된다.