• 제목/요약/키워드: Ligand Effects

검색결과 404건 처리시간 0.035초

Effects of Ginsenosides on $GABA_A$ Receptor Channels Expressed in Xenopus Oocytes

  • Choi, Se-Eun;Choi, Seok;Lee, Jun-Ho;Paul J.Whiting;Lee, Sang-Mok;Nah, Seung-Yeol
    • Archives of Pharmacal Research
    • /
    • 제26권1호
    • /
    • pp.28-33
    • /
    • 2003
  • Ginsenosides, major active ingredients of Panax ginseng, are known to regulate excitatory ligand-gated ion channel activity such as nicotinic acetylcholine and NMDA receptor channel activity. However, it is not known whether ginsenosides affect inhibitory ligand-gated ion channel activity. We investigated the effect of ginsenosides on human recombinant $GABA_A$ receptor (${\alpha}_1{\beta}_1{\gamma}_{2s}$) channel activity expressed in Xenopus oocytes using a two-electrode voltage-clamp technique. Among the eight individual ginsenosides examined, namely, $Rb_1$, $Rb_2$, Rc, Rd, Re, Rf, $Rg_1$ and $Rg_2$, we found that Rc most potently enhanced the GABA-induced inward peak current ($I_{GABA}$). Ginsenoside Rc alone induced an inward membrane current in certain batches of oocytes expressing the $GABA_A$ receptor. The effect of ginsenoside Rc on $I_{GABA}$ was both dose-dependent and reversible. The half-stimulatory concentration ($EC_{50}$) of ginsenoside Rc was 53.2$\pm$12.3 $\mu$M. Both bicuculline, a $GABA_A$ receptor antagonist, and picrotoxin, a $GABA_A$ channel blocker, blocked the stimulatory effect of ginsenoside Rc on $I_{GABA}$. Niflumic acid (NFA) and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), both $CI^{-1}$ channel blockers, attenuated the effect of ginsenoside Rc on I$I_{GABA}$. This study suggests that ginsenosides regulated $GABA_A$ receptor expressed in Xenopus oocytes and implies that this regulation might be one of the pharmacological actions of Panax ginseng.

수용액에서의 Ho(III) 착물의 흡수 스펙트럼에 영향을 미치는 온도 및 리간드 효과에 관한 연구 (Temperature and Ligand Effects on the Ho(Ⅲ) Absorption Spectra in Aqueous Solution)

  • 김미경;한화진;전승준;김건
    • 대한화학회지
    • /
    • 제36권6호
    • /
    • pp.824-831
    • /
    • 1992
  • 수용액에서 Ho(III) 이온과 간단한 리간드 사이의 착물 형성에 대한 온도와 리간드 농도의 영향을 흡수 스펙트럼을 이용하여 연구하였다. Hypersensitive 전이$(^5I_8\;\to\;^5G_6)$의 전이세기 변화는 온도와 리간드의 영향을 크게 받고, 이 변화는 Ho(Ⅲ) 이온의 배위 환경 변화로 해석될 수 있다. 이 스펙트럼에서 관찰된 전이세기를 분석하여 Judd-Ofelt 전이세기 파라미터($\Omega_\lambda$, $\lambda$ = 2, 4, 6)를 구했다. 이 파라미터들 중 $\Omega_2$ 파라미터가 온도와 리간드에 의해 가장 큰 변화를 보이고, 이 변화로부터 $Cl^-$${NO_3}^-$가 수용액에서 내부권 착물을 형성함을 보였다

  • PDF

Production rind Characterization of the Polyclonal Anti-peptide Antibody for $\beta$-adrenergic Receptor

  • Kim, Hee-Jin;Shin, Chan-Young;Sang Bong lee;Ko, Kwang-Ho
    • Biomolecules & Therapeutics
    • /
    • 제2권4호
    • /
    • pp.303-309
    • /
    • 1994
  • The analysis of membrane receptors for hormones and neurotransmitters has progressed considerably by pharmacological and biochemical means and more recently through the use of specific antibodies. Two kinds of antibodies could be produced, one is from synthetic peptides and the other from proteins such as purified receptor. Anti-peptide antibodies gave some advantages; epitope is evident and also receptor purification in quantity is not prerequisite. It can be also applied to the study of receptor structure-activity relationship. The purpose of the present study was 1) to produce and characterize a polyclonal antibody against a synthetic $\beta$2-adrenergic receptor peptide(Phe-Gly-Asn-Phe-Trp-Cys-Phe-Trp-Thr-Ser-Ile-Asp-Val-Leu) and 2) to determine the effects of this antibody on the $\beta$-adrenergic receptor ligand interaction. The peptide sequence contains an amino acid residue such as Asp-113 which was identified as one of important component for receptor-ligand interaction in site-directed mutagenesis studies. Production of antibody was performed by immunization of rabbits through popliteal lymph node with the peptide coupled with Keyhole Limpet Hemocyanin (KLH). The titer of antibody against this peptide was 1 : 1000. The anti-peptide antibody was able to detect a 67 kDa protein band in western blot corresponding to the molecular weight of the $\beta$-adrenergic receptor in partially purified receptor fraction derived from guinea pig lung. The antisera inhibited the specific binding of [$^3$H]dihydroalprenolol to $\beta$-adrenergic receptor in a concentration-dependent manner. The results from this study suggest that the peptide sequence selected in the present study is important for the receptor ligand interaction.

  • PDF

Electron Paramagnetic Resonance Study of Bis(N-methyl-2-amino-1-cyclopentenedithiocarboxylato)Copper (II)

  • Woo-Seong Kim;Young-Inn Kim;Sung-Nak Choi
    • Bulletin of the Korean Chemical Society
    • /
    • 제11권2호
    • /
    • pp.85-88
    • /
    • 1990
  • The electron paramagnetic resonance (EPR) spectrum of the copper (II) complex with the 2-methylamino-1-cyclo-pentene-1-dithiocarboxylate (acdc) anion, $Cu(N-CH_3acdc)_2$ has been studied in the diamagnetic host lattices afforded by the corresponding divalent nickel, zinc, cadmium and mercury complexes. EPR parameters of the complex support the exclusive use of sulfur atoms by the ligand in metal binding. A combination of host lattice structure and covalency effects can be account for the observed spin-Hamiltonian parameters.

Insulin-Like Growth Factor-I Induces Androgen Receptor Activation in Differentiating C2C12 Skeletal Muscle Cells

  • Kim, Hye Jin;Lee, Won Jun
    • Molecules and Cells
    • /
    • 제28권3호
    • /
    • pp.189-194
    • /
    • 2009
  • The modulating effect of IGF-I on the regulation of AR gene expression and activation in skeletal muscle cells remains poorly understood. In this study, the effects of IGF-I treatment on AR induction and activation in the absence of AR ligands were examined. Differentiating C2C12 cells were treated with different concentrations (0-250 ng/ml) of IGF-I or for various periods of time (0-60 min) of 250 ng/ml IGF-I. Treatment of C2C12 cells with IGF-I resulted in a dose- and time-dependent increase in total AR and phosphorylated AR (Ser 213). IGF-I treatment also led to significantly increased AR mRNA expression when compared with the control. The levels of skeletal ${\alpha}-actin$ and myogenin mRNA, known target genes of AR, were also significantly upregulated after 5 or 10 min of treatment with IGF-I. Confocal images revealed that IGF-I stimulated nuclear localization of AR in the absence of ligands. In addition, an electrophoretic mobility shift assay indicated that IGF-I stimulated the AR DNA binding activity in a time-dependent manner. The present results suggest that IGF-I stimulates the expression and activation of AR by ligand-independent mechanism in differentiating C2C12 mouse skeletal muscle cells.

Ginseng saponins and the treatment of osteoporosis: mini literature review

  • Siddiqi, Muhammad Hanif;Siddiqi, Muhammad Zubair;Ahn, Sungeun;Kang, Sera;Kim, Yeon-Ju;Sathishkumar, Natarajan;Yang, Dong-Uk;Yang, Deok-Chun
    • Journal of Ginseng Research
    • /
    • 제37권3호
    • /
    • pp.261-268
    • /
    • 2013
  • The ginseng plant (Panax ginseng Meyer) has a large number of active ingredients including steroidal saponins with a dammarane skeleton as well as protopanaxadiol and protopanaxatriol, commonly known as ginsenosides, which have antioxidant, anticancer, antidiabetic, anti-adipocyte, and sexual enhancing effects. Though several discoveries have demonstrated that ginseng saponins (ginsenosides) as the most important therapeutic agent for the treatment of osteoporosis, yet the molecular mechanism of its active metabolites is unknown. In this review, we summarize the evidence supporting the therapeutic properties of ginsenosides both in vivo and in vitro, with an emphasis on the different molecular agents comprising receptor activator of nuclear factor kappa-B ligand, receptor activator of nuclear factor kappa-B, and matrix metallopeptidase-9, as well as the bone morphogenetic protein-2 and Smad signaling pathways.

OenNen-Styrene DVB 합성수지에 의한 U(VI), Fe(II), Sm(III) 이온들의 흡착 (Adsorption of U(VI), Fe(II), Sm(III) Ions on OenNen-Styrene DVB Synthetic Resin)

  • 이치영;김준태
    • 환경위생공학
    • /
    • 제22권3호
    • /
    • pp.77-87
    • /
    • 2007
  • The ion exchange resins have been synthesized from chlormethyl styrene - 1,4 - divinylbenzene(DVB) with 1%, 3%, and 5%-crosslinking and macro cyclic ligand of OenNen-$H_4$ by copolymerization method and the adsorption characteristics of uranium(VI), iron(II) and samarium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ${UO_2}^{2+}>Fe^{2+}>Sm^{3+}$ ion. The adsorption was in order of 1%, 3%, and 5% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvent.

The relationship between serum adiponectin and inflammatory cytokines in obese Korean juveniles

  • Byun, Sung Hwan;Kwon, Eun Byul;Kim, Se Young
    • Clinical and Experimental Pediatrics
    • /
    • 제57권12호
    • /
    • pp.533-537
    • /
    • 2014
  • Purpose: Obesity is related to systemic inflammatory processes causing cardiovascular complications. Intercellular adhesion molecule-1 (ICAM-1), CD40 ligand (CD40L), P-selectin are newly described mediators of inflammation and have a significant effect in atherosclerosis. Adiponectin has shown anti-inflammatory effects in adults. The aim of this study was to evaluate the relationship between adiponectin and inflammatory mediators in children and adolescents. Methods: Fifty children or adolescents, twenty two with a body mass index (BMI) over 95th percentile, and twenty eight with a BMI below 75th percentile were included in the study. Serum soluble ICAM-1 (sICAM-1), P-selectin, CD40L, lipid profiles, aspartate aminotransferase, alanine aminotransferase, glucose and insulin were measured to evaluate associations with adiponectin. Comparison of these variables was performed between the obese and the nonobese group. Results: We found a adiponectin to be significant lower and sICAM-1 significant higher in the obese group compared to the nonobese group, but there were no significant differences in P-selectin and soluble CD40L. Adiponectin was negatively associated with ICAM-1 and P-selectin in the obese group. Conclusion: Negative associations of adiponectin with ICAM-1 and P-selectin in obese children and adolescents suggest that serum adiponectin level may represent the inflammatory status.

OenNdien수지에 의한 금속 이온의 흡착 (Adsorption of Metal Ions on OenNdien Resin)

  • 강영식;노기환;김준태
    • 환경위생공학
    • /
    • 제20권3호
    • /
    • pp.27-35
    • /
    • 2005
  • The ion exchange resins have been synthesized from chlormethyl styrene - 1,4 -divinyl-benzene(DVB) with $1\%,\;4\%,\;and\;10\%$-crosslinking and macrocyclic ligand of cryptand type by copolymerization method and the adsorption characteristics of uranium(VI), calcium(II) and lutetium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium $(UO_2^{2+})>calcium(Ca^{2+})>lutetium(Lu^{3+})$ ion. The adsorption was order of $1\%,\;4\%,\;and\;10\%$ crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

백지의 사람비만세포 사이토카인 및 케모카인 발현 양상 (Effect of Angelicae Dahuricae Radix on Expression of Cytokines and Chemokines Levels in Human Mast Cells (HMC))

  • 김명규;이세나;임종필;임강현
    • 대한본초학회지
    • /
    • 제22권1호
    • /
    • pp.81-87
    • /
    • 2007
  • Objectives: Angelicae Dahuricae Radix (Baek-Ji in Korean, BJ) is well known to be used as a medicine for cold, headache, supraorbital pain, nasal congestion, and toothache. Little is understood about the roles of BJ in the cytokine and chemokine secretion by immune cells. This study was designed to find out the effects of BJ on the cytokine and chemokine secretion in human mast cells (HMC). Methods : We treated BJ according to consistency on HMC and measured cytokines and chemokines levels using flow cytometry CBA system. Results: In BJ treated group. the expression of interferon-inducible protein 10 (IP-l0), monocyte chemoattractant protein-1 (MCP-1), chemokine (C-X-C motif) ligand 9 (MIG), and interleukin 10 (IL-l0) levels were decreased significantly and chemokine (C-C motif) ligand 5 (RANTES), IL-8, $interferone-{\gamma}$ ($IFN-{\gamma}$), and tumor necrosis factor alpha (TNF-a) were decreased significantly. Conclusion : The results of this experiment supposed that the treatment of BJ will ameliorate the secreting levels of some chemokines or cytokines such as IP-10, MCP-1, MIG, IL-10, RANTES, IL-8, $IFN-{\gamma}$, and TNF-a.

  • PDF