• 대한방사성의약품학회지
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• 제1권1호
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• pp.31-37
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• 2015

Chelating agents 1,4,7-triazacyclononanetriacetic acid (NOTA), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and 30-amino-3,14,25-trihydroxy-3,9,14,20,25-penta-azatriacontane-2,10,13,21,24-pentaone (desferrioxamine, DFO) were labeled with $^{68}Ga$ and tested in vitro properties to check the feasibility of using DFO as a bifunctional chelating agent or renal imaging agent. The chelating agents of concentration $2{\mu}M$ were labeled with $^{68}Ga$ in 0.1 M HCl at pH 1.7-10.3 at room temperature and $80^{\circ}C$ and the optimal pH for labeling each chelating agent was found. And then, the chelating agents were labeled with $^{68}Ga$ in various concentration of chelating agents at optimal pH. The labeled chelating agents were subject to stability test in human serum and to binding studies to human red blood cell (RBC) and plasma protein. The optimal pH's of NOTA, DOTA and DFO for $^{68}Ga$-labeling were 4.4, 3.6 and 5.6, respectively. DFO ($10{\mu}M$) showed high labeling efficiency (>97%) at pH 5.6. All the labeled chelating agents showed high stability in human serum. $^{68}Ga$-DFO showed low RBC binding but significant amount was bound to plasma protein. The results demonstrated that $^{68}Ga$-DFO can be used as a bifunctional chelating agent but not as a renal imaging agent.

• Archives of Pharmacal Research
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• 제19권5호
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• pp.359-367
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• 1996

The pharmacokinetics of LB20304 was investigated following intravenous (IV) and oral administration to rats and dogs. Additionally, in vitro metabolism and serum protein binding studies were also conducted. The total body clearance, apparent volume of distribution, terminal half-life, and extent of bioavailability were 21.8 ml/min/kg, 2265 ml/kg, 93.6 min, and 30.8% for rats; and 7.95 ml/min/kg, 4144 ml/kg, 363 min, and 81.1% for dogs, respectively. LB20304 was stable in the liver microsome containing NADPH generating system and its serum protein binding was 58.5-65.8% for rats, 19.1-29.6% for dogs, and 56.9-59.6% for humans. Its tissue concentration levels in lever, stomach, small intestine, and kidney were 9.5 to 26.1 times greater than plasma level, but the concentration in testis was quite low and that in brain was negligible in rats. The 48 hr urinary recovery of the dose was 44% for IV dosing and 14% for oral dosing, shereas the 48 hr biliary recovery of the dose was 6.4% for IV dosing and 4.5% for oral dosing in rats. In summary, the pharmacokinetic properties of LB20304 were characterized by its good oral absorption, long plasma half-life, and good tissue distribution.

• KSBB Journal
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• 제11권6호
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• pp.630-635
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• 1996

IgG와 알부민이 고스트 적혈구의 분산하에서 적 혈구의 세포막에 흡착되었다. 용액중 IgG의 농도가 0 O.1mg/mL일 때, 고스트 적혈구의 부피비가 5% 에 서 45%로 증가함에 따라 흡착으로 인한 용액중의 IgG의 농도감소는 14%에서 45%로 증가하였고, h hardened 고스트 척혈구 분산시가 고스트 적혈구 분산시보다 더 많은 단백질이 흡착되었다. 용액중 알부민의 농도가 0.075mg/mL일 때, 고스트 적헐구 의 부피가 5%에셔 70%로 증가함에 따라 용액중의 얄부민의 농도감소는 12% 에서 47%로 증가하였다. 흡착시간에 대한 IgG의 농도변화를 측정한 결과 단 백질의 흡착은 빠른 속도로 일어남을 알 수 있었고, 적혈구당 흡착된 단백질 분자수를 계산한 결과 용액 내 적혈구의 수가 증가할수록 적혈구당 흡착된 분자 수는 감소하였다.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.277.1-277.1
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• 2003

A high-performance liquid chromatographic method using the liquid extraction procedure was developed for the determination of L -FMAUS. a new L -FMAU derivative, in rat plasma and urine using 3-aminophenyl sulfone as an internal standard. A 100-${\mu}\ell$ aliquot of distilled water containing the L -cysteine (100 mg/$m\ell$) was added to a 100-${\mu}\ell$ aliquot of biological sample. L-Cysteine was employed to protect binding between 5'-thiol of l and protein in the biological sample. (omitted)

• Molecules and Cells
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• 제44권2호
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• pp.116-125
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• 2021

Cardiovascular diseases (CVDs) are the most common cause of death in patients with nonalcoholic fatty liver disease (NAFLD) and dyslipidemia is considered at least partially responsible for the increased CVD risk in NAFLD patients. The aim of the present study is to understand how hepatic de novo lipogenesis influences hepatic cholesterol content as well as its effects on the plasma lipid levels. Hepatic lipogenesis was induced in mice by feeding a fat-free/high-sucrose (FF/HS) diet and the metabolic pathways associated with cholesterol were then analyzed. Both liver triglyceride and cholesterol contents were significantly increased in mice fed an FF/HS diet. Activation of fatty acid synthesis driven by the activation of sterol regulatory element binding protein (SREBP)-1c resulted in the increased liver triglycerides. The augmented cholesterol content in the liver could not be explained by an increased cholesterol synthesis, which was decreased by the FF/HS diet. HMG-CoA reductase protein level was decreased in mice fed an FF/HS diet. We found that the liver retained more cholesterol through a reduced excretion of bile acids, a reduced fecal cholesterol excretion, and an increased cholesterol uptake from plasma lipoproteins. Very low-density lipoproteintriglyceride and -cholesterol secretion were increased in mice fed an FF/HS diet, which led to hypertriglyceridemia and hypercholesterolemia in Ldlr-/- mice, a model that exhibits a more human like lipoprotein profile. These findings suggest that dietary cholesterol intake and cholesterol synthesis rates cannot only explain the hypercholesterolemia associated with NAFLD, and that the control of fatty acid synthesis should be considered for the management of dyslipidemia.

• BMB Reports
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• 제31권5호
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• pp.515-518
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• 1998

Adhesive interaction of the platelet glycoprotien IIb-IIIa (GP IIb-IIIa) with a plasma protein, such as fibrinogen, plays an important role in thrombosis and hemostasis. The specific sequence Arg-Gly-Asp (RGD) is critical for the binding of fibrinogen to platelet. To examine and characterize the GP IIb-IIIa antagonist from natural sources, we have developed a simple enzyme-linked immunosorbant assay (ELISA) system. The GP IIb-IIIa complex was purified to homogeneity from platelet Iysates by the combination of two affinity chromatographic methods using the synthetic RGD peptide (GRGDSPK)-immobilized Sepharose and wheat germ lectin-Sepharose. The synthetic peptide GRGDSP inhibits GP IIb-IIIa binding to immobilized fibrinogen with an $IC_{50}$ of $1.5\;{\mu}M$. Venoms of three different snake species and a Korean scolopendra extract have strong antagonistic activities for the binding of human fibrinogen to the platelet GP IIb-IIIa complex. The $IC_{50}$ values of the snake venom s and scolopendra were in the range of $5.5\;{\mu}g$ to $60\;{\mu}g$. These results provide meaningful information for developing antiplatelet agents.

• 한국가정과학회지
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• 제9권1호
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• pp.81-88
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• 2006

IGFs and IGFBPs have an important role in controlling glucose homeostasis. This study was conducted to investigate the changes of insulin-like growth factor(IGF)-I. IGF-II and IGF binding proteins (IGFBPs) on fasting and postprandial state in Korean diabetes, Twenty eight healthy subjects and fifty seven diabetic patients participated in this study. The healthy subjects were not knowingly suffered from any disease and were not receiving any medical treatment, and diabetic subjects were undergo medical treatment, continuously. Weight and height were measured and body mass index (BMI) was calculated as weight (kg) divided by the square of height (m2). Blood pressure was measured. Plasma lipid profiles were analyzed by enzymatic methods, plasma Insulin and glucose levels were measured in fasting and postprandial state, respectively. The levels of serum IGFs and IGFBP-3 were measured by radioimmunoassay (RIA). The levels of glucose and insulin were significantly higher in diabetes than normal subjects on fasting as well as postprandial state (p<0.0l). The levels of IGF-I was significantly lower in diabetes than normal subjects, however in postprandial state, there was no significant difference between diabetes and control subjects, The levels of IGF-II were significantly lower in diabetes than control subjects both fasting and postpradial state, The level of IGFBP-3 were not significantly different between diabetes and normal subjects. Fasting IGF-I, IGF-II and IGFBP-3 levels were positively correlated with those levels on postprandial state, fasting IGe levels of IGF-I levels were positively correlated with fasting insulin levels, and postprandial IGF-I levels were positively correlated with fasting glucose, postprandial insulin and postprandial insulin levels, plasma triglyceride levels were correlated with plasma triglyceride levels. The IGFBP-3 levels were not correlated with IGF components, glucose, insulin and plasma lipids, These results demonstrate that in diabetes, the components IGF-I/IGFBPs system were significantly correlated with plsma glucose and insulin levels both fasting and postprandial state.

• Journal of Ginseng Research
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• 제46권3호
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• pp.348-356
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• 2022

Background: Gintonin is a ginseng-derived exogenous G-protein-coupled lysophosphatidic acid (LPA) receptor ligand. Gintonin exerts its neuronal and non-neuronal in vitro and in vivo effects through LPA receptor subtypes. However, it is unknown whether gintonin can bind to the plasma membrane of cells and can transactivate the epidermal growth factor (EGF) receptor. In the present study, we examined whether gintonin-biotin conjugates directly bound to LPA receptors and transactivated the EGF receptor. Methods: We designed gintonin-biotin conjugates through gintonin biotinylation and examined whether gintonin-biotin conjugate binding sites co-localized with the LPA receptor subtype binding sites. We further examined whether gintonin-biotin transactivated the EGF receptor via LPA receptor regulation via phosphor-EGF and cell migration assays. Results: Gintonin-biotin conjugates elicit [Ca²⁺]_i transient similar to that observed with unbiotinylated gintonin in cultured PC3 cells, suggesting that biotinylation does not affect physiological activity of gintonin. We proved that gintonin-biotin conjugate binding sites co-localized with the LPA1/6 receptor binding sites. Gintonin-biotin binding to the LPA1 receptor transactivates the epidermal growth factor (EGF) receptor through phosphorylation, while the LPA1/3 receptor antagonist, Ki16425, blocked phosphorylation of the EGF receptor. Additionally, an EGF receptor inhibitor AG1478 blocked gintonin-biotin conjugate-mediated cell migration. Conclusions: We observed the binding between ginseng-derived gintonin and the plasma membrane target proteins corresponding to the LPA1/6 receptor subtypes. Moreover, gintonin transactivated EGF receptors via LPA receptor regulation. Our results suggest that gintonin directly binds to the LPA receptor subtypes and transactivates the EGF receptor. It may explain the molecular basis of ginseng physiology/pharmacology in biological systems.

• The Journal of Korean Physical Therapy
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• 제19권4호
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• pp.1-14
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• 2007

Background: It is generally accepted that skeletal muscle contraction is triggered by nerve impulse and intracellular $Ca^{2+}\;([Ca^{2+}]_i)$ released from intracellular $Ca^{2+}$ stores such as sarcoplasmic reticulum (SR). Specifically, this process, called excitation-contraction (E-C) coupling, takes place at intracellular junctions between the plasma membrane, the transverse (T) tubule L-type $Ca^{2+}$ channel (dihydropyridine-sensitive L-rype $Ca^{2+}$ channel, DHPR, also called tetrads), and the SR $Ca^{2+}$ release channel (ryanodine-sensitive $Ca^{2+}$ release channel, RyR, also called feet) of internal $Ca^{2+}$ stores in skeletal muscle cells. Furthermore, it has been reported that the $Ca^{2+-}$ dependent and -independent contraction determine the expression of skeletal muscle genes, thus providing a mechanism for tightly coupling the extent of muscle contraction to regulation of muscle plasticity-related excitation-transcription (E-T) coupling. Purpose: Expression and activity of plasticity-associated enzymes in gastrocnemius muscle strips have not been well studied, however. Methods: Therefore, in this study the expression and phosphorylation of E-C and E-T coupling-related mediators such as protein kinases, ROS(reactive oxygen species)- and apoptosis-related substances, and others in gastrocnemius muscles from rats was examined. Results: I found that expression and activity of MAPKs (mitogen-activated protein kinases, ERK1/2, p38MAPK, and SAPK/JNK), apoptotic proteins (cleaved caspase-3, cytochrome c, Ref-1, Bad), small GTP-binding proteins (RhoA and Cdc42), actin-binding protein (cofilin), PKC (protein kinase C) and $Ca^{2+}$ channel (transient receptor potential channel 6, TRPC6) was observed in rat gastrocnemius muscle strips. Conclusion: These results suggest that MAPKs, ROS- and apoptosis-related enzymes, cytoskeleton-regulated proteins, and $Ca^{2+}$ channel may in part functionally import in E-C and E-T coupling from rat skeletal muscles.

• BMB Reports
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• 제52권7호
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• pp.445-450
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• 2019

TTYH2 is a calcium-activated, inwardly rectifying anion channel that has been shown to be related to renal cancer and colon cancer. Based on the topological prediction, TTYH2 protein has five transmembrane domains with the extracellular N-terminus and the cytoplasmic C-terminus. In the present study, we identified a vesicle transport protein, ${\beta}$-COP, as a novel specific binding partner of TTYH2 by yeast two-hybrid screening using a human brain cDNA library with the C-terminal region of TTYH2 (TTYH2-C) as a bait. Using in vitro and in vivo binding assays, we confirmed the protein-protein interactions between TTYH2 and ${\beta}$-COP. We also found that the surface expression and activity of TTYH2 were decreased by co-expression with ${\beta}$-COP in the heterologous expression system. In addition, ${\beta}$-COP associated with TTYH2 in a native condition at a human colon cancer cell line, LoVo cells. The over-expression of ${\beta}$-COP in the LoVo cells led to a dramatic decrease in the surface expression and activity of endogenous TTYH2. Collectively, these data suggested that ${\beta}$-COP plays a critical role in the trafficking of the TTYH2 channel to the plasma membrane.