• 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.

• Proceedings of the Plant Resources Society of Korea Conference
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• 1995.01a
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• pp.41-41
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• 1995

• Journal of Plant Biology
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• v.34 no.4
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• pp.297-302
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• 1991

The effects of polyamines on auxin polar transport were studied in corn coleoptile segments. Among putresine, spermidine and spermine tested in labelled auxin transport, spermidine inhibited auxin polar transport most strongly. Its inhibitory effect appeared after 1 h of transport period. Spermidine inhibited labelled auxin and 14C-benzoic acid accumulation into the tissue in the various pH range tested (pH 4.0-8.0). These results suggest that the inhibition of auxin transport may not be due to decrease in pH by spermine the effect of decreased pH in the extracellular space.

• Journal of Ginseng Research
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• v.14 no.1
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• pp.6-9
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• 1990

Specific activities of ADC and ODC from 2-4 year old ones were higher than that from seedlings whereas those activities were not changed significantly from 2 to 4 years. Generally, activity of ADC was predorminant compared to that of ODC. Free arginine content in roots was much higher than that of leaves. And arginase specific activity from roots was higher than that of leaves. Cumulative results suggest that putrscine formation from ornithine in roots may be more effective than leaves and contribute to putrescine biosynthesis to some extract.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.1
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• pp.101-110
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• 2020

Transient receptor potential canonical 4 (TRPC4) channel is a nonselective calcium-permeable cation channels. In intestinal smooth muscle cells, TRPC4 currents contribute more than 80% to muscarinic cationic current (mIcat). With its inward-rectifying current-voltage relationship and high calcium permeability, TRPC4 channels permit calcium influx once the channel is opened by muscarinic receptor stimulation. Polyamines are known to inhibit nonselective cation channels that mediate the generation of mIcat. Moreover, it is reported that TRPC4 channels are blocked by the intracellular spermine through electrostatic interaction with glutamate residues (E728, E729). Here, we investigated the correlation between the magnitude of channel inactivation by spermine and the magnitude of channel conductance. We also found additional spermine binding sites in TRPC4. We evaluated channel activity with electrophysiological recordings and revalidated structural significance based on Cryo-EM structure, which was resolved recently. We found that there is no correlation between magnitude of inhibitory action of spermine and magnitude of maximum current of the channel. In intracellular region, TRPC4 attracts spermine at channel periphery by reducing access resistance, and acidic residues contribute to blocking action of intracellular spermine; channel periphery, E649; cytosolic space, D629, D649, and E687.

• Journal of the Korean Chemical Society
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• v.47 no.5
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• pp.466-471
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• 2003

The effect of polyamines on the cabbage phospholipase D(PLD) activity was investigated. The PLD activity was determined by pH-stat titration of phosphatidic acid, one of the enzymatic reaction product, using phosphatidyl choline small unilamellar vesicles as a substrate. The cabbage PLD was activated approximately 4 fold by spermine at 1 mM concentration. This spermine effect appears to be similar to the previous report on the PLD activation of rat brain mitochondrial fraction. It was also found that cationic polypetides such as polylysine and polyhistidine exerted a marked enhancement effect on the cabbage PLD. Particularly polyhistidine exerted approximately 5.5 fold enhancement effect at 0.062 mM concentration. The polyamine effect on the cabbage PLD was reexamined in the phosphatidylcholine/sodium dodecyl sulfate mixed micellar system. The relevance of polyamine effect on PLD activity is discussed in relation to the active site of PLD.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.522-526
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• 2006

To investigate the effects of UV-B on fatty acid composition, lipid peroxidation and biochemical defense responses of plant, kidney bean (Phaseolus vulgaris L.) was subjected to enhanced UV-B irradiation [daily dose : 0.02.(No UV-B) and 11.36 (enhanced UV-B) $kJ\;m^{-2};UV-B_{BE}$] for 3 weeks. UV-B drastically inhibited both height and dry weight of kidney bean. The content of malondialdehyde significantly increased by about 50% after 3 weeks of UV-B irradiation. The ratio of unsaturated to saturated fatty acids of kidney bean was increased by UV-B irradiation. Three major polyamines of kidney bean leaves : putrescine, spermidine and spermine, were observed. All of the polyamine contents were increased with UV-B irradiation. These results suggested that enhanced UV-B radiation caused oxidative stress on lipids and biochemical protection responses might be activated to prevent from damaging effects of oxidative stress generated by UV-B irradiation.

• Journal of Environmental Science International
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• v.29 no.4
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• pp.415-421
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• 2020

This study was conducted to determine the optimum conditions for the treatment of polyamine to promote pollen germination and improve the fruiting rate by overcoming fertilization defects in low-temperature strawberry cultivation. The optimum temperature for pollen germination of strawberries was 30 ℃ for Seolhyang and 25 ℃ for Maehyang, and Seolhyang had a higher pollen germination rate than that of Maehyang. The addition of polyamines, namely spermine and putrescine to the medium improved the pollen germination rate and spermine treatment showed a better effect than putrescine treatment. The proper polyamine type and treatment concentration for enhancing the potency of pollen germination was 500 μM of spermine for both Seolhyang and Maehyang, which improved the pollen germination rate by 19-23% compared with that of the control. However, combined treatment of spermine and putrescine, resulted in a lower germination rate lower than that of the single treatment. Our results indicated that the treatment of polyamines during flowering in protected cultivation of strawberrise can improve the fruiting rate by overcoming the problem of poor pollen germination due to low temperature.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.189-200
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• 1993

Ornithine decarboxylase is the first and rate limiting enzyme in the biosynthesis of polyamines in mammalian cells. During cell growth the enzyme is regulated by rapid changes in the level of its mRNA and protein. To explore the molecular basis of these changes, ODC-specific complementary DNA (cDNA) clones were isolated from a bovine cDNA library. This region of the cDNA contained a portion of the open reading frame, a 3'noncoding region, and a poly-A tail of 456, 348, and 14 nucleotides, respectively. A comparison of the deduced sequence of the carboxyl terminal 151 amino acids of ODC with amino acid sequences in the same region of the enzyme from human, mouse, rat, and hamster showed greater than 88% identity in these proteins. The highly conserved nature of the amino acid sequences may be related to the important role of ODC in cell growth and differentiation.

• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.105-110
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• 1994

In order to study on the effect of polyamine inhibitors and polyamines on adventitious root formation the correlation between adventitious root formation and polyamine levels were investigated in cultured soybean (Glycine max L.) cotyledons. Adventitious root formation was inhibited in medium containing 10$^{-4}$ -10/ sup -2/ M polyamine inhibition such as $\alpha$-difluoromethylornithine (DFMO), $\alpha$-difluoromethylarginine (DFMA), cyclohexylammonium sulfate (CHA), dicyclohexyl-amine (DCHA) and methylglyoxal-bis (guanylhydrazone) (MGBG). An inhibitory effects at 10$^{-3}$ M MCBG were much higher than other treatments. Treatment with 10$^{-3}$ M MGBG plus 10$^{-5}$ M spermine led to reversal of the effects of MGBG alone. The polyamine levels were sharply increased in the first few days in each treatnent compared to control. The remarkably increasing polyamine contents were observed in medium supplemented spermine.