• Journal of Ginseng Research
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• 제18권2호
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• pp.95-101
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• 1994

Saponin of Panax ginseng (C.A. Meyer) is composed of Protopanaxatriol (PT) and Protopanaxa- diol (PD). We investigated the effects of PT and PD on the contractility and $^{45}Ca$ uptake in the pig coronary artery. Isometric tension in the helical strips and $^{45}Ca$ uptake in the ring strips were measured in the presence or absence of PT and PD. PT and PD did not affect the high K+ (40 mM)-induced contraction but relaxed the ACh-induced contraction in a dose4ependent manner (1~10 mg/dl). The vasorelaxing effect of PT on the ACh-induced contraction was more potent than that of PD. Those relaxations were partially suppressed by the rubbing of endothelium removal. ACh-induced contraction in the $Ca^{2+}$-free Tyrode's solution was suppressed by the pretreatment of PT or PD. Following the depletion of ACh-sensitive intracellular $Ca^{2+}$ pool, ACh-induced contraction was suppressed by the pratreatment of PT or PD. With the pretreatment of PT or PD, $^{45}Ca$ uptake by high K+ (43 mM) was not changed but that by ACh was suppressed in the pig coronary artery. From the above results, we suggested that the vasorelaxing effect of PT and PD of Panax ginseng was due to inhibition of intracellular $Ca^{2+}$ release, inhibition of $Ca^{2+}$ uptake via receptor-operated $Ca^{2+}$ channels and in part a release of vasorelaxing factor from endothelium in pig coronary artery.

• 한국동물학회지
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• 제38권1호
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• pp.10-19
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• 1995

동면동물인 한국관박쥐(Korean greater horseshoe bat)와 비롱면 롱물인 토끼의 근소포체가 지니는 생리 및 근조직의 형태적 특징을 비교해 보고자 본 실험을 수행하여 다음과 같은 결론을 내렸다 Caffeine과 Mgcl2는 농도별로 처리하고, p연와 온도에 변화를 주는 등 각각의 생리조건하에서 한국관박쥐와 토끼 대흉근 근소포체 마이크로솜의 C32' 흡수정도가 다르게 나타났으며, Ca2'ATPase 활성 역시 상이함을 보였는데. 이로 미루어 보아 in vivo 상태에서 두 동물의 근소포체가 지니는 생리적 특성에 차이가 있을 것으로 추측된다. 형태학적 측면에서도 근심유의 수기와 미토콘드리아의 크기에 있어서 뚜렷한 차이를 발견할 수 있었는데. 이는 두 동물의 대흉근이 수행하는 운동의 종류와 관련이 있을 것으로 생각된다.

• The Korean Journal of Physiology
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• 제28권1호
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• pp.27-35
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• 1994

We investigated the alterations in basal tone of aortic strips by changing the Ca concentration, basal $^{45}Ca$ uptake and $^3H-nitrendipine$ binding of the single cells of aortic smooth muscles in the spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. While the basal tone of the aortic strips in WKY rats was not affected by alteration of Ca concentration, that in SHR was decreased by the removal of Ca from the bath solution and was recovered by the restoration of Ca to normal levels. This contraction increased in a Ca concentration-dependent manner and reached a maximum at 2 mM Ca. The basal tone of aorta in SHR was suppressed by verapamil $(10^{-6}M)$. The basal tone of aorta in SHR increased about 50% in the strips of endothelial rubbing, compared with that of intact endothelium. Basal $^{45}Ca$ uptake in the aortic single smooth muscle cells of SHR was greater than that of WKY (p<0.01), Specific bindings of $[^3H]nitrendipine$ in the aortic single smooth muscles of SHR and WKY were saturable. The dissociation constant $(K_d)\;was\;0.71{\pm}0.15\;and\;1.18{\pm}0.08nM$ SHR, respectively, and the difference in $K_d$ between two strains was statistically significant (p<0.03). The maximal binding capacity $(B_{max})\;was\;34.6{\pm}3.2\;and\;47.4{\pm}4.3\;fmol/10^6$ SHR respectively, and the difference of $(B_{max})$ between two strains was statistically significant (p<0.05). from the above results, it is suggested that the increase of Ca influx via potential-operated Ca channels and the increase of the number of dihydropyridine-sensitive Ca channels contribute to high basal tone of the aortic strips in SHR.

• Molecules and Cells
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• 제43권1호
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• pp.66-75
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• 2020

Saturated fatty acids contribute to β-cell dysfunction in the onset of type 2 diabetes mellitus. Cellular responses to lipotoxicity include oxidative stress, endoplasmic reticulum (ER) stress, and blockage of autophagy. Palmitate induces ER Ca²⁺ depletion followed by notable store-operated Ca²⁺ entry. Subsequent elevation of cytosolic Ca²⁺ can activate undesirable signaling pathways culminating in cell death. Mitochondrial Ca²⁺ uniporter (MCU) is the major route for Ca²⁺ uptake into the matrix and couples metabolism with insulin secretion. However, it has been unclear whether mitochondrial Ca²⁺ uptake plays a protective role or contributes to lipotoxicity. Here, we observed palmitate upregulated MCU protein expression in a mouse clonal β-cell, MIN6, under normal glucose, but not high glucose medium. Palmitate elevated baseline cytosolic Ca²⁺ concentration ([Ca²⁺]_i) and reduced depolarization-triggered Ca²⁺ influx likely due to the inactivation of voltage-gated Ca²⁺ channels (VGCCs). Targeted reduction of MCU expression using RNA interference abolished mitochondrial superoxide production but exacerbated palmitate-induced [Ca²⁺]_i overload. Consequently, MCU knockdown aggravated blockage of autophagic degradation. In contrast, co-treatment with verapamil, a VGCC inhibitor, prevented palmitate-induced basal [Ca²⁺]_i elevation and defective [Ca²⁺]_i transients. Extracellular Ca²⁺ chelation as well as VGCC inhibitors effectively rescued autophagy defects and cytotoxicity. These observations suggest enhanced mitochondrial Ca²⁺ uptake via MCU upregulation is a mechanism by which pancreatic β-cells are able to alleviate cytosolic Ca²⁺ overload and its detrimental consequences.

• 대한약리학회지
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• 제30권1호
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• pp.117-124
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• 1994

Phospholamban은 심근 근장그물 $Ca^{2+}-ATPase$ 조절단백이다. 조절작용기전은 탈인산화된 phospholamban에 의해 $Ca^{2+}-ATPase$가 억제됨으로 나타나며, 이 phospholamban이 인산화됨으로 $Ca^{2+}-ATPase$에 대한 억제가 반전됨을 보인다. 최근에 phospholamban의 cytoplasmic domain만으로 $Ca^{2+}-ATPase$를 억제하기에는 불충분하다는 보고가 있어 본 실험을 계획하였다. $Ca^{2+}-ATPase$의 활성을 억제하는 phospholamban domain을 밝히기 위하여 합성한 phospholamban 펩타이드(아미노산 1-25)의 $Ca^{2+}$ uptake에 대한 효과를 살펴보았다. 골격근 근장그물에서 $Ca^{2+}-ATPase$를 분리한 후 phosphatidylcholine이나 phosphatidylcholine과 phosphatidylserine을 포함한 liposome에 재조합시켰다. Phospholamban 펩타이드는 phosphatidylcholine을 이용하여 재조합된 vesicles의 초기 $Ca^{2+}$ uptake rate를 억제하고, cAMP 의존성 protein kinase의 catalytic subunit로 인산화시킨 phospholamban 펩타이드는 이 억제를 반전시킴을 보여 주었다. Phosphatidylcholine과 phosphatidylserine을 포함한 제조합 vesicles에서도 같은 양상을 보였다. 이상의 결과로 미루어 볼 때 인산화 sites를 포함하고 있는 phospholamban의 cytoplasmic domain은 그 자체만으로도 근장그물 칼슘펌프를 억제하기에 충분하다고 결론지을 수 있다.

• 생명과학회지
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• 제8권2호
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• pp.208-215
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• 1998

제주도 근해에서 다량 채취되고 있는 해양갈조류인 톳의 살아있지 않은 건조한 생물질을 Ca-alginate법(Ca-ALG), Ba-alginate법(Ba-ALG), polyethylene glycol법(PEG), $\kappa$-carrageenan법(CARR) 등으로 고정화시켜 고정화방법에 따른 Cu의 흡착기능을 검토하였다. 생물질의 첨가량이 증가함에 따라서 Cu의 제거율은 증가하였으나 흡착량은 감소하였다. 그러나 초기농도가 증가함에 따라서는 cu의 흡착량이 증가하였다. 고정화법에 따른 Cu의 흡착량은 Ca-ALG>Ba-ALG>PEG>CARR순으로 감소하엿다. 고정화된 생물질에 으한 Cu의 흡착은 Freundlich 흡착 등온식 보다는 Langmuir 흡착 등온식을 잘 따름을 알 수 있었다.

• 한국작물학회지
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• 제47권2호
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• pp.108-115
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• 2002

The effects of long-term fertilization on soil properties and nutrient availability are not well documented for cassava cultivation in Vietnam. In 1990, a field research plots were established with 12 treatments to test the effect of different rates of nitrogen (N), phosphorus (P) and potassium (K) on soil properties in Acrisols at Thai Nguyen University in Northern Vietnam. In 1999, composite soil samples (0 to 20cm depth) were collected from eight selected plots for measurements of nutrient supply rates by ion exchange membrane probes and for growing corn and canola in a growth chamber with and without added lime. Generally, long-term nitrogen (N) fertilization increased available N supply rates but decreased available potassium (K) and magnesium (Mg). Long-term phosphorus(P) applications increased canola N, calcium (Ca) and Mg uptake. Canola P uptake increased with increased P rates only when lime was added. Long-term K applications increased canola N, K, Ca, Mg uptake but only significantly increased corn N uptake. Liming significantly increased uptake of N, P, K, Ca, Mg and S for both corn and canola. However, N $H_{4-}$N, K and Mg soil supply rates were reduced when lime was added, due to competition between Ca from the added lime and other nutrients.

• Clinical and Experimental Reproductive Medicine
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• 제16권1호
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• pp.1-7
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• 1989

배양중인 생쥐 난자의 성숙에 미치는 배양액 내 calcim의 영향을 알아보기 위하여 1.71mM $Ca^{2+}$을 처리한 배양액과 $Ca^{2+}$이 존재하지 않는 배양액에서 난자를 배양하여 불꽃 원자 흡수 분광 광도계를 이용하여 배양된 난자의 $Ca^{2+}$농도를 측정하였다. 1) $Ca^{2+}$처리한 배양액에서 배양된 cumulus-cell이 제거된 (denuded oocyte)난자들은 시간이 지남에 따라 $Ca^{2+}$농도가 높게 나타났고, 2) $Ca^{2+}$처리하지 않은 배양액에서는 denuded난자는 3시간째 배양될때 부터 $Ca^{2+}$양이 줄어 들었다. Cumulus-enclosed난자는 $Ca^{2+}$존재하에서는 GVBD가 일어났다고 생각되는 4시간까지 계속 증가를 보인 반면 $Ca^{2+}-free$에서는 배양되지 않은 난자와 거의 차이가 없게 나타났다. 3) 핵막붕괴가 일어난 후부터 15시간까지 배양시컸을 때에는 CEO와 denuded oocyte에서 공히 $Ca^{2+}$의 농도는 다시 증가된 상태로 계속 되었다. 이런 결과로 미루어 보아 난자 성숙시 부터 성숙과정이 끝날때가지 exteral $Ca^{2+}$이 요구되고 있음을 증명해 주고있다. 그러나 이러한 세포질내의 $Ca^{2+}$및 bound calcium이 난자 성숙시부터 어떤 역활을 하고 있는 기작에 대해서는 좀 더 연구가 있어야겠다.

• Journal of Plant Biology
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• 제36권4호
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• pp.321-326
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• 1993

Sugar uptake is accompanied with H+-substrate-symport generally. Both H+/sugar-and H+/K+ stoichiometries during the sugar-uptake have been reported to be exactly 1 : 1. This paper reports that the stoichiometries were enhanced dramatically by the addition of CaCl2 into the medium and by the high cell density of 200 $\mu$L pc/mL. The concentration of free Ca2+ ions in the cells increased significantly with cell density. It is suggested that the free Ca2+ ions are responsible for the change of stoichiometry of sugar transport system by regulation of H+ ion level of biomembrane.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1996년도 정기총회 및 학술발표회
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• pp.39-39
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• 1996

Extracts were prepared from six different poisonous mushrooms in order to identify biologically active natural ligands. The effects of these extracts were examined on the microsomal $^{45}$ Ca$^{2+}$ uptake and $^{45}$ Ca$^{2+}$ release. Five out of six species apparently inhibited the activity of total microsomal ATPases prepared from the epithelial cells of pig airway. (omitted)ted)