• Parasites, Hosts and Diseases
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• 제32권1호
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• pp.19-26
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• 1994

Toxoplasma 약독주(ME49 주)의 배양계 확립을 위하여 뇌내 cyst를 마우스 복강에 주입하고 1, 3, 5 그리고 7일후 다시 얻어 배양기 부착성 세포를 배양하는 방법으로 ME49주를 배양하였으며, ME49주의 성장에 미치는 CAMP 및 DHFR억제제의 영향을 관찰하였다. ME49주로 감염된 대식 세포의 형태학적 관찰은 Giemsa 염색방법을 이용하였고 성장정도는 $[^3H]-uracil$ 표지량을 대조군에 대한 비로 나타내었다. 감염 3일 및 5일이 경과된 후에 채취한 복수의 대식세포에서 ME49 주의 bradyzoite가 주로 판찰되었으며, 배양기에서 3일 이상 경과된 후에는 pseudocyst를 형성하기 시작하였고, 5일 10일이 경과되면서 pseudocyst의 크기가 증가하였다. CAMP를 농도별로 처리하였을 때 3일째와 5일째의 복수를 5일간 및 10일간 배양했을 때 농도의존적으로 성장을 촉진하였다. DHFR 억제제중 pyrimethamine의 경우 농도의존적인 성장억제효과를 나타냈고 methotrexate의 경우엔 ME49 주 bradyzoite의 성장에 영향을 미치지 않는 것으로 나타났다. 이상의 결과로 마우스 대식세포내에서 bradyzoite의 배양이 가능하고 그 배양조건은 3일째와 5일째 복수를 5일 이상 10일 정도 배양하는 것이 적당하며 CAMP 및 pyrimethamine이 bradyBoite의 성장을 각각 촉진 및 억제하는 것으로 나타났다.

• 대한수의학회지
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• 제36권2호
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• pp.327-335
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• 1996

Recently in spite of the interest on the regulation of intracellular $Mg^{2+}$ by neurotransmitters or drugs, the magnesium ion($Mg^{2+}$) regulation by ${\alpha}_1$-adrenoceptor stimulation has not been studied in the heart yet. To elucidate the regulation of ${\alpha}_1$-adrenoceptor stimulation-induced $Mg^{2+}$ release and the effects of ${\alpha}_1$-adrenoceptor stimulation on pathophysiological conditions, in this study we have evaluated the effects of phenylephrine, PMA, $H_7$. staurosporine, verapamil and lidocaine on $Mg^{2+}$ release in perfused guinea pig heart. During preperfusion exogenous $Mg^{2+}$ was added to the medium to give 1.2mM 15min before starting to addition of drugs, and then the infusion of exogenous $Mg^{2+}$ was stopped. $Mg^{2+}$ in the perfusate leaving the heart was measured by atomic absorption spectrophotometry. $Mg^{2+}$ free solution produced an increase in heart rate and phenylephrine elicited $Mg^{2+}$ release from the heart. $Mg^{2+}$ release by phenylephrine was abolished by combined treatment with prazosin. By contrast, cardiac $Mg^{2+}$ uptake induced by a protein kinase C(PKC) activator, PMA was abolished by a selective PKC inhibitor, staurosporine. And the phenylephrine-induced $Mg^{2+}$ release was not affected by the PKC inhibitor, $H_7$. When verapamil or lidocaine was added to perfusing solution, $Mg^{2+}$ release was potentiated by phenylephrine from perfused guinea pig heart. These results suggest that ${\alpha}_1$-adrenoceptor stimulation caused $Mg^{2+}$ release and that PKC is not involved in ${\alpha}_1$-adrenoceptor mediated $Mg^{2+}$ release from perfused guinea pig heart. Under pathophysiological conditions, the $Mg^{2+}$ alteration by ${\alpha}_1$-adrenoceptor stimulation is considerable.

• Applied Microscopy
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• 제23권1호
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• pp.1-14
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• 1993

본 연구는 세포질 액포의 수와 기능적으로 상호작용하는 정단세포막(丁端細胞膜)의 역동적(力動的) 변화로 인한 세포수송의 조절과 세포막의 재순환(再循環) 과정의 증거를 분석(分析)하였다. 주사전자현미경(走査電子顯微鏡) 관찰에 의하면 Turtle bladder 점막(粘膜)에는 다음 세 증류의 주요세포가 있다. 과립성세포(顆粒性細胞)는 방광점막(膀胱粘膜) 세포의 대다수를 차지하는 것으로서 총 세포수의 80%에 해당하며, 나머지 20%의 세포는 탄산탈수효소가 풍부한 A 및 B형으로 분류되는 상피세포(上皮細胞)가 특징이다. 탄산탈수효소가 풍부한 두 종류의 세포내의 관상액포(管狀液胞)나 대부분의 액포에서 horseradish peroxidase의 흡수를 조사한 결과, 세포막부분이 정단세포질(丁端細胞質) 액포에 내화(內化)되어 있었다. 마치 탄산탈수효소를 함유한 세포가 세포내(細胞內) 액포(液胞)를 소유하고 있는것 같으며 이 세포내 액포는 정단세포막으로 재순환(再循環)하는 proton 펌프를 지니는 것으로 생각된다. Turtle bladder에서 과립상세포는 두렷한 세포외분필(細胞外分泌) 기작에 의하여 다량의 mucin과 기타 단백질을 능동적으로 분비하는 constitutive pathway로서 믿어지며. 조절된 분비경로를 통해 방광상피세포(膀胱上皮細胞)가 mucin을 분비하는 가능성에 대해서는 엄밀하게 규명되어있지 않으므로 이러한 vesicular transport 상당부분이 미결상태로 남아있다.

• The Korean Journal of Physiology and Pharmacology
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• 제20권6호
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• pp.629-639
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• 2016

The present study was designed to investigate the characteristics of gintonin, one of components isolated from Korean Ginseng on secretion of catecholamines (CA) from the isolated perfused model of rat adrenal gland and to clarify its mechanism of action. Gintonin (1 to $30{\mu}g/ml$), perfused into an adrenal vein, markedly increased the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. The gintonin-evoked CA secretion was greatly inhibited in the presence of chlorisondamine ($1{\mu}M$, an autonomic ganglionic bloker), pirenzepine ($2{\mu}M$, a muscarinic $M_1$ receptor antagonist), Ki14625 ($10{\mu}M$, an $LPA_{1/3}$ receptor antagonist), amiloride (1 mM, an inhibitor of $Na^+/Ca^{2+}$ exchanger), a nicardipine ($1{\mu}M$, a voltage-dependent $Ca^{2+}$ channel blocker), TMB-8 ($1{\mu}M$, an intracellular $Ca^{2+}$ antagonist), and perfusion of $Ca^{2+}$-free Krebs solution with 5mM EGTA (a $Ca^{2+}$chelater), while was not affected by sodium nitroprusside ($100{\mu}M$, a nitrosovasodialtor). Interestingly, LPA ($0.3{\sim}3{\mu}M$, an LPA receptor agonist) also dose-dependently enhanced the CA secretion from the adrenal medulla, but this facilitatory effect of LPA was greatly inhibited in the presence of Ki 14625 ($10{\mu}M$). Moreover, acetylcholine (AC)-evoked CA secretion was greatly potentiated during the perfusion of gintonin ($3{\mu}g/ml$). Taken together, these results demonstrate the first evidence that gintonin increases the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. This facilitatory effect of gintonin seems to be associated with activation of LPA- and cholinergic-receptors, which are relevant to the cytoplasmic $Ca^{2+}$ increase by stimulation of the $Ca^{2+}$ influx as well as by the inhibition of $Ca^{2+}$ uptake into the cytoplasmic $Ca^{2+}$ stores, without the increased nitric oxide (NO). Based on these results, it is thought that gintonin, one of ginseng components, can elevate the CA secretion from adrenal medulla by regulating the $Ca^{2+}$ mobilization for exocytosis, suggesting facilitation of cardiovascular system. Also, these findings show that gintonin might be at least one of ginseng-induced hypertensive components.

• 한국환경성돌연변이발암원학회지
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• 제25권2호
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• pp.60-65
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• 2005

The human solute carrier, SLC41Al, is a $Mg^{2}+$ transporter that is regulated by extracellular magnesium. Although intracellular magnesium plays a fundamental role in cellular metabolism, little is known about how $Mg^{2}+$ is taken up and controlled by cells. Magnesium plays a fundamental role in cellular metabolism so that its control within the body is critical. Magnesium homeostasis is principally a balance between intestinal absorption of dietary magnesium and renal excretion of urinary magnesium. The kidney, mainly the distal convoluted tubule, controls magnesium reabsorption. Although renal reabsorption is under the influence of many hormones, selective regulation of magnesium transport is due to intrinsic control involving transcriptional processes and synthesis of transport proteins. Using microarray analysis, identification of the genetic elements involved with this transcriptional control has been begun. SLC41A1(GenBank Accession No. AJ514402), comprises 10 putative transmembrane domains, two of which are highly homologous to the integral membrane part of the prokaryote transports $Mg^{2}+$ and other divalent cations $Sr^2+,\;Zn^2+,\;Cu^2+,\;Fe^2+,\;Co^2+,\;Ba^2+,\;and\;Cd^2+,\;but\;not\;Ca^2+,\;Mn^2+,\;and\;Ni^2+.$ Transport of $Mg^{2}+$ by SLC41Al is rheogenic, voltage dependent, and not coupled to Na or Cl. Expressed SLC41Al transports a range of other divalent cations: $Mg^{2+},\;Sr^{2+},\;Zn^{2+},\;Cu^{2+},\;Fe^{2+},\;Co^{2+},\;Ba^{2+},\;and\;Cd^{2+}$. The divalent cations $Ca^{2+},\;Mn^{2+},\;and\;Ni^{2+}$and the trivalent ion $Gd^{3+}$ did not induce currents nor did they inhibit $Mg^{2+}$ transport. The nonselective cation $La^{3+}$ abolishes $Mg^{2+}$ uptake. Computer analysis of the SLC41Al protein structure reveals that it belongs to MgtE protein family & suggested that the human solute carrier, SLC41Al, might be a eukaryotic $Mg^{2+}$ transporter closely related $(60-70\%)$ protein encoded by SLC41A2 is a $Mg^{2}+$ transporter that might be involved in magnesium homeostasis in epithelial cells also transports a range of other divalent cations: $Ba^2,\;Ni^2,\;CO^2,\;Fe^2,\;or\;Mn^2,\;but\;not\;Ca^2,\;Zn^2,\;or\;Cu^{2+}$ that may have related functional properties.

• Toxicological Research
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• 제3권2호
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• pp.129-141
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• 1987

Hepatocytes isolated from rats which have been pretreated with phenobarbital (80 mg/kg for 3 days), were able to take up N-acetylcysteine from surrounding medium and were able to synthesize the reduced glutathione ($GSH^{\ast}-3$) intracellularly. The N-acetylcysteine is quickly deacetylated after the uptake and increases the pool size of cysteine, which was very low initially (5 nmol/$10^6$ cells). From this increased intracellular cysteine pool, GSH was synthesized. Freshly isolated rat hepatocytes contained a high level of GSH (30 nmol/$10^6$ cells), but upon incubation with the diethylmaleate, it was markedly decreased (10 nmol/$10^6$ cells). The hepatocytes with depleted GSH have lost viability upon incubations with acetaminophen (5mM) and paraquat (2 mM). However, when the N-acetylcysteine (1 mM) was added to this incubation condition, these chemical induced hepatocellular necrosis were prevented for longer durations. This N-acetylcysteine dependent protective effect against the hepatotoxic chemicals was lost by adding methionine sulfoximine (10 mM), an inhibitor of GSH biosynthesis. Both the carbontetrachloride (5 mM) and chioroform (5 mM) added to the incubation medium caused rapid losses of GSH and cell viability, even without the prior depletion of cellular GSH. However, again, if the 1mM N-acetylcysteine was supplemented, the rates of losses of GSH and cell viability were retarded in both cases. Even though large amounts of the added N-acetylcysteine was present in the cell, N-acetylcysteine conjugate of acetaminophen was not formed. Instead, only large amounts of GSH conjugate of the drug was produced. Thus, it is concluded that the added N-acetylcysteine is taken up and utilized for resynthesis of GSH. In turn, this resynthesized GSH contributes to the protection against cytotoxicity inducible with hepatotoxic drugs.

• Molecular & Cellular Toxicology
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• 제5권4호
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• pp.298-303
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• 2009

(-)-Epigallocatechin-3-gallate (EGCG), a major flavonoid in green tea has multiple health benefits including chemoprevention, anti-inflammatory, anti-diabetic, and anti-obesity effects. In connection with these effects, EGCG can be a candidate to help the treatment of metabolic diseases. Metformin is a widely used anti-diabetic drug regulating cellular energy homeostasis via AMP-activated protein kinase (AMPK) activation. Therefore, the combination of metformin with EGCG may have additive or synergistic effects on treatment of type 2 diabetes. Nevertheless, there is no report for the pharmacokinetic and/or pharmacodynamic interaction of EGCG with metformin. Here, we evaluated the pharmacokinetic and pharmacodynamic interaction between metformin and EGCG in rats. Pharmacokinetics parameters of metformin were measured after oral administration of metformin in rats pre-treated with EGCG (10 mg/kg) or saline for 7 days. The results showed that there is no significant difference in pharmacokinetic parameters between saline control and EGCG-treated group. In addition, the hepatic AMPK activation by metformin in EGCG-treated rats was also similar to the control. The lack of additive effects of EGCG on AMPK activation or intracellular uptake of metformin was also evaluated in cells in the presence or absence of EGCG. Treatment of HepG2 cells with EGCG inhibited the metformin-induced AMPK activation. Combined results suggested that EGCG has no effect on the pharmacokinetics of metformin but may contribute to metformin action.

• 생명과학회지
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• 제25권11호
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• pp.1290-1297
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• 2015

에탄올 생산 세균 Zymomonas mobilis에서 에탄올 생산 경로의 핵심으로 작용하는 효소인, pyruvate decarboxylase(pdc) 유전자의 불활성 실험을 통해, PDC 활성이 50% 감소된 PDC 활성 변형균주가 분리되었다. 이러한 균주들의 에탄올 탄소대사 흐름이 고부가가치 화합물인 피루브산, 숙신산 및 젖산 등으로 전환되는지를 발효 실험을 통해 평가하였다. 하지만 pdc의 발현을 중지시키기 위해 cat-삽입형-pdc와 pdc-결손형 아형 유전자를 전기천공법을 이용해 야생형 균주 ZM4의 염색체에 이식하기 위한 다수의 시도에도 불구하고, 이러한 방법을 통해 분리된 균주들은 대부분 부분적 유전자 불활성 특성을 보였으며, PDC 활성이 완전히 손실된 삭제 돌연변이 균주를 획득할 수는 없었다. PDC활성이 변형된 돌연변이 균주의 발효 실험에서, 야생형 균주와 비교 시 감소된 PDC 효소 활성의 변화로 인해 기질 흡수율과 에탄올 생산율이 감소되어 피루브산 생산이 약 2.5 g l^-1 정도로 증가함을 확인하였으나, 젖산과 숙신산의 생산에 현저한 농도 변화를 보이지 못했다. 이러한 결과는 Z. mobilis의 산화환원 에너지가 PDC 효소 활성에 의한 에탄올 생산 경로에 전적으로 의존하여 발생한다는 것을 암시하였다. 상기 결과를 토대로 pdc 유전자의 완전한 불활성 유도와 산화환원 에너지의 균형은, 젖산 생산을 위한 lactate dehydrogenase, 숙신산 생산을 위한 pyruvate dehydrogenase와 malic enzyme과 같은 효소의 활성 증가를 통해, 세포내 NAD와 NADH 농도의 산화환원 균형이 이루어져야 발생할 수 있음을 시사하였다.

• 생명과학회지
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• 제26권12호
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• pp.1470-1476
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• 2016

바이러스성 출혈성 패혈증 바이러스(VHSV)는 넙치를 포함한 어류 양식의 막대한 피해를 일으키는 바이러스 병원체이며, VHSV가 생성하는 6개의 바이러스 단백질들 중에서 NV 단백질이 병원성에 관여하는 것으로 알려져 있다. VHSV-감염 넙치를 이용한 전사체 마이크로 어레이의 선행 분석 결과에 의하면 VHSV 감염이 해당과정 효소들의 mRNA 발현을 억제함으로써 넙치 세포에서 ATP 생성을 감소시켰음을 알 수 있었다. 이들 결과를 토대로, 본 연구에서는 VHSV NV 단백질이 해당과정 효소인 glucokinase의 발현에 미치는 영향을 검토하였다. 본 연구의 결과에 의하면, NV 단백질은 넙치 세포에서 glucokinase의 mRNA 발현을 감소시켰으며, 새롭게 동정한 glucokinase의 유전자 프로모터의 활성 실험결과, NV 단백질이 glucokinase의 프로모터 활성을 저해함을 알 수 있었다. 이와 같은 작용 결과들로 인하여 VHSV NV 단백질의 발현이 세포 내로의 포도당 흡수 또한 감소시켰다. 이러한 결과들은 VHSV NV 단백질이 유전자 발현의 전사 수준에서 음성적으로 해당과정의 효소 발현을 조절함을 의미하며, 결국 세포 내 에너지의 결핍으로 넙치의 폐사로 이어질 가능성을 보여주는 것이다.

• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.783-796
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• 2006

The periodontium is a topographically complex organ consisting of epithelial tissue, soft and mineralized tissues. Structures comprising the periodontium include the gingiva, periodontal ligament (PDL) , cementum and the alveolar bone. The molecular mechanism of differentiation in PDL fibroblast cells remain unclear. Amino acid transporters play an important role in supplying nutrition to normal and cancer cells and for cell proliferation. Amino acid transport system L is a major nutrient transport system responsible for the Na+-independent transport of neutral amino acids including several essential amino acids. The system L is divided into two major subgroups, the L-type amino acid transporter 1 (LAT1) and the L-type amino acid transporter 2 (LAT2). In this study, the expression pattern of amino acid transport system L was, therefore, investigated in the differentiation of PDL fibroblast cells. To determine the expression level of amino acid transport system L participating in intracellular transport of amino acids in the differentiation of PDL fibroblast cells, it was examined by RT-PCR, observation of cell morphology, Alizaline red-S staining and uptake analysis after inducing experimental differentiation in PDL fibroblast cells isolated from mouse molar teeth. The results are as follows. 1. The LAT1 mRNA was expressed in the early stage of PDL fibroblast cell differentiation. This expression level was gradually reduced by differentiation- inducing time and it was not observed after the late stage. 2. The expression level of LAT2 mRNA was increased in time-dependent manner during differentiation induction of PDL fibroblast cells. 3. There was no changes in. the expression level of 4F2hc mRNA, the cofactor of LAT1 and LAT2, during differentiation of PDL fibroblast cells. 4. The expression level of ALP mRNA was gradually increased and the expression level of Col I mRNA was decreased during differentiation of PDL fibroblast cells. 5. The L-leucine transport was reduced by time from the early stage to the late stage in PDL fibroblast cell differentiation. As the results, it is considered that among neutral ammo acid transport system L in differentiation of PDL fibroblast cells, the LATl has a key role in cell proliferation in the early stage of cell differentiation and the LAT2 has an important role in the late stage of cell differentiation for providing cells with neutral amino acids including several essential amino acids.