• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.137-146
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• 1999

Interactions among dexamethasone, dehydroepiandrosterone (DHEA), lipopolysaccharide (LPS), and antimycin A on the glutamate uptake and the polyamine uptake were investigated in primary cultures of rat cerebral cortical astrocytes to examine the effects of dexamethasone and DHEA on the regulatory role of astrocytes in conditions of increased extracellular concentrations of glutamate or polyamines. 1. $[^3H]Glutamate$ uptake: LPS and antimycin A decreased $V_{max},$ but both drugs had little effect on $K_m.$ Dexamethasone also decreased basal $V_{max}$ without any significant effect on $K_m.$ And dexamethasone further decreased the antimycin A-induced decrease of $V_{max}.$ DHEA did not affect the kinetics of basal glutamate uptake and the change by LPS or antimycin A. 2. $[^{14}C]Putrescine$ uptake: LPS increased $V_{max},$ and antimycin A decreased $V_{max}.$ They showed little effect on $K_m.$ Dexamethasone decreased $V_{max}$ of basal uptake and further decreased the antimycin A-induced decrease of $V_{max},$ and also decreased $V_{max}$ to less than control in LPS-treated astrocytes. DHEA did not affect $K_m$ and the change of $V_{max}$ by LPS or antimycin A. 3. $[^{14}C]Spermine$ uptake: Antimycin A decreased $V_{max},$ and LPS might increase $V_{max}.\;K_m$ was little affected by the drugs. Dexamethasone decreased basal $V_{max}$ and might further decrease the antimycin A-induced decrease of $V_{max}.$ And dexamethasone also decreased $V_{max}$ to less than control in LPS-treated astrocytes. DHEA might increase basal $V_{max}$ and $V_{max}$ of LPS-treated astrocytes. 4. $V_{max}$ of glutamate uptake by astrocytes was increased by putrescine (1000 ${\mu}M$ & 2000 ${\mu}M$) and spermidine (200 ${\mu}M,$ 500 ${\mu}M$ & 2000 ${\mu}M$). Spermine, 200 ${\mu}M$ (and 100 ${\mu}M$), also increased $V_{max},$ but a higher dose of 2000 ${\mu}M$ decreased $V_{max}.\;K_m$ of glutamate uptake was not significantly changed by these polyamines, except that higher doses of spermine showed tendency to decrease $K_m$ of glutamate uptake. In astrocytes, dexamethasone inhibited the glutamate uptake and the polyamine uptake in normal or hypoxic conditions, and the polyamine uptake might be stimulated by LPS and DHEA. Polyamines could aid astrocytes to uptake glutamate.

• Journal of the Korean Chemical Society
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• v.28 no.1
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• pp.70-73
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• 1984

• Journal of the Korean Chemical Society
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• v.26 no.4
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• pp.247-249
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• 1982

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.385-392
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• 1996

Changes in polyamine titers and enzyme activities during radicle growth of Glycine max were studied in order to investigate the effect of ferulic acid in regulation of polyamine biosynthesis. Among eight compounds used, gallic acid stimulated the radicle growth and ferulic acid inhibited it significantly. During the radicle growth of Glycine max, the content of putrescine was shown the highest level at the second day, while at the fourth day spermidine was the highest and spermine followed. Ornithine decarboxylass (ODC, EC 4.1.1.17) seems to be responsible for biosynthesis of putrescine. As the concentration of ferulic acid (0.001, 0.01, 0.1 mM) treated increased, the content of spermine was gradually enhanced and putrescine was increased at 0.001~0.01 mM, decreased after 0.1 mM concentration but spermidine was not affected. Ferulic acid elevated ODC and S-adenosylmethionine decarboxylass (SAMDC, EC 4.1.1.50) activity. ODC activity was increased more than 120% and SAMDC activity was increased about 50% more than that of the control. Diamine oxidase (DAO EC, 1.4.3.6) activity was enhanced about 20% at low concentration, decreased after then.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.247-250
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• 2006

We herein studied the effect of polyamines (putrescine, spermidine and spermine) on growth and indigo biosynthesis in hairy root cultures of Polygonum tinctorium Lour. Our results revealed that polyamine treatment increased hairy root growth and indigo biosynthesisat all tested concentrations, with the highest growth rate (4.4 g/ flask) and indigo yield (216 ug/g) induced by 70 mg/L putrescine. These results show far the first time that the growth rates and indigo biosynthesis of Polygonum tinctorium hairy roots may be improved by addition of polyamines to the liquid culture medium.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.186-190
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• 1997

This study was carried out to investigate the effect of polyamines, salt strength. sucrose and gelling agents on the regeneration of plantlets by meristem culture of Aloe arborescens Mill. and Aloe vera L.. Shoot multiplication was more effective when 10mg/ l spermine in Aloe arborescens and 1mg/ l spermidine in Aloe vera added into MS medium than when other polyamines were treated into media. A quarter strength of MS medium was effective for rooting of shoots regenerated. Higher concentration of sucrose (45g/ l) was more effective for shoot regeneration. Addition of 4g/ l gelrite into the medium was effective for induction of multiple shoots from Aloe than that of agar or other concentrations of gelrite. When plantlets regenerated from meristem culture were transferred to pot. survival rate of plantlets was 80% on perlite and was 95% on vermiculite. respectively.

• Journal of Plant Biology
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• v.39 no.2
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• pp.107-112
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• 1996

To study the compensatory aspect of putrescine biosynthetic enzyme n tobacco suspension cultured cells, we examined the contents of the cellular polyamines and the activities of arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17) in the tobacco suspension cells treated with $\alpha$-difluoromethyl arginine (DFMA) or $\alpha$-difluoromethyl ornithine (DFMO). In the untreated cells, the content of the cellular putrescine was decreased during the first 3 hours and then subsequently increased. However, the content of the cellular spermidine and spermine remained constant during the incubation time. While ADC activity increased after 6 hours, ODC activity decreased following the rapid increase until 6 hours. DFMA induced the decrease in the contents of putrescine and spermidine, and the increase in that of spermine. It also caused the inhibition of ADC and ODC activities throughout the incubation time. DFMO produced the stimulation of ADC activity about 2 times of untreated cells and the decrease in the content of putrescine about 50% of them at 12 hour. The application of putrescine or cycloheximide prevented the increase of ADC activity by DFMO but that of actinomycin-D did not show any detectable effect. The stimulation of ADC activity by DFMO in tobacco suspension cultured cells was probably due to the enhancement of de novo synthesis for ADC protein, which might be regulated in the translation step by the content of the cellular putrescine.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.2003-2007
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• 2011

We report a highly sensitive surface-enhanced Raman scattering (SERS) platform for the selective trace analysis of mercury (II) ions in drinkable water using aptamer-conjugated silver nanoparticles. Here, an aptamer designed to specifically bind to $Hg^{2+}$ ions in aqueous solution was labelled with a TAMRA moiety at the 5' end and used as a Raman reporter. Polyamine spermine tetrahydrochloride (spermine) was used to promote surface adsorption of the aptamer probes onto the silver nanoparticles. When $Hg^{2+}$ ions are added to the system, binding of $Hg^{2+}$ with T-T pairs results in a conformational rearrangement of the aptamer to form a hairpin structure. As a result of the reduced of electrostatic repulsion between silver nanoparticles, aggregation of silver nanoparticles occurs, and the SERS signal is significantly increased upon the addition of $Hg^{2+}$ ions. Under optimized assay conditions, the concentration limit of detection was estimated to be 5 nM, and this satisfies a limit of detection below the EPA defined limit of 10 nM in drinkable water.

• BMB Reports
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• v.28 no.3
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• pp.191-196
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• 1995

The role of polyamines in skeletal myoblast differentiation was investigated using the polyamine metabolic inhibitor methylglyoxal bis(guanylhydrazone)(MGBG). Concentrations of intracellular free spermidine and spermine increased 2 to 2.5-fold at the onset of myoblast fusion. The systhesis of actin, and creatine kinase activity both dramatically increased during myotube formation. However, MGBG at a concentration of 0.5 mM not only abolished the increase of intracellular free polyamines, but also reduced cell fusion to almost half the level of untreated cells, without noticeable morphological alteration. The production of actin, and creatine kinase activity were almost completely abolished by MGBG. The inhibition of myoblast fusion by MGBG was partially recovered with 0.1 mM of spermidine or spermine added externally. Results indicate that polyamines are necessary for normal myoblast differentiation. Since the first indication of myoblast differentiation is alignment of muscle cells and membrane fusion of adjacent cells, and since polyamine depletion completely inhibited the synthesis of actin, which might be associted with membranes, polyamine might be involved in myoblast differentiation through membrane reorganization events.

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.447-454
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• 2009

The transport of spermidine into a cyanobacterium, Synechocystis sp. pec 6803, was characterized by measuring the uptake of $^{14}C$-spermidine. Spermidine transport was shown to be saturable with an apparent affinity constant ($K_m$) value of $67{\mu}M$ and a maximal velocity ($V_{max}$) value of 0.45 nmol/min/mg protein. Spermidine uptake was pH-dependent with the pH optimum being 8.0. The competition experiment showed strong inhibition of spermidine uptake by putrescine and spermine, whereas amino acids were hardly inhibitory. The inhibition kinetics of spermidine transport by putrescine and spermine was found to be noncompetitive with $K_i$ values of 292 and $432{\mu}M$, respectively. The inhibition of spermidine transport by various metabolic inhibitors and ionophores suggests that spermidine uptake is energy-dependent. The diminution of cell growth was observed in cells grown at a high concentration of NaCl. Addition of a low concentration of spermidine at 0.5 mM relieved growth inhibition by salt stress. Upshift of the external osmolality generated by either NaCl or sorbitol caused an increased spermidine transport with about 30-40% increase at 10 mosmol/kg upshift.