• Title, Summary, Keyword: ${\alpha}$-Difluoromethylornithine

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Effects of Polyamine Inhibitors and Polyamines on the Adventitious Root Formation from Soybean Cotyledons (Polyamine 합성 저해제와 Polyamine이 대두 자엽 부정근의 형성에 미치는 영향)

  • 한태진;이동원;이순희
    • 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.

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Effects of Inhibitors (DFMO, DFMA) on Polyamine Synthetic Enzymes (ADC, ODC) during Ovarian Development of the Tobacco Budworm, Helicoverpa assulta (담배나방의 난소발생시 폴리아민 합성효소에 미치는 저해제의 효과)

  • 우장환;김문익;김선희;이형철;정성은
    • Journal of the Korean Society of Tobacco Science
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    • v.21 no.1
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    • pp.26-35
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    • 1999
  • Effects of $\alpha$-difluoromethylornithine (DFMO) and $\alpha$-difluoromethylarginine (DFMA), inhibitors of polyamine syntheic enzymes (ornithine decarboxylase, arginine decarboxylase), on ovary were investigated during pupal-adult development of Helicoverpa assulta. Two inhibitors (DFMO, DFMA) showed definite inhibition effects on ovarian development. The inhibition effect on ovaries weight was more marked in DFMA-injection than that observed in DFMO-injection. Two inhibitors (DFMO, DFMA) gave rise to a peculiar decrease in ornithine decarboxylase (ODC) or arginine decarboxylase (ADC) activity in ovaries, 72 hrs (5-day old pupa) post injection. However, DFMO clearly exhibited supression of ODC activity after 96 hrs (6-day old pupa). In addition, two inhibitors (DFMO, DFMA) diminished putrescine content in the ovary. The spermidine level was slightly decreased by each injection of the inhibitors. However, two inhibitors (DFMO, DFMA) raised the spermine content at certain developmental stages in the ovary. Although the effect of DFMA was less severe, two inhibitors (DFMO, DFMA) caused not only an overall delay in ovarian development, but also abnormalities in cellular differentiation. Noted effects in the pupal ovary were the appearance of irregular nurse cells and partial destruction of follicle epidermal cells. Adult ovary showed rapid degradation of nurse cells, a reduction in the number of follicle epidermal cells and immature oocytes that had a low yolk content.

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Effects of CDP-Choline, Aminoguanidine and Difluoromethylornithine on the ECS-induced Impairment of Active Conditioned Response Retention (백서의 조건회피반응-유지에 대한 경련성 전기충격의 저해작용에 미치는 CDP-Choline, Aminoguanidine, 및 Difluoromethylornithine의 영향에 관한 연구 : 뇌내 Acetylcholine과 Polyamine 함량-변동에 연관하여)

  • Kim, Hyung-Gun;Kim, Chang-Hyun;Choi, Sang-Hyun;Ihm, Suk-Young;Lee, Min-Soo;Chun, Boe-Gwun
    • The Korean Journal of Pharmacology
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    • v.28 no.2
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    • pp.115-128
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    • 1992
  • The training of male wistar rats for active conditioned response (ACR) was performed by one daily training session of 30 consecutive trials for 10 successive days using a two-way shuttle box, and the rats that showed 10 or more ACRs on the last day were treated for further 10 days with electroconvulsive shock (ECS : 50 mA, 0.5 msec; 100 Hz; 1.5 sec) and the following compounds. On the 20th day, all the rats were tested for the ACR rention. The ECS regimens were one ECS per day for 10 days with one day interval $(5{\times}ECS)$, one ECS at 3 hrs (ECS-3h), and one ECS at 24 hrs (ECS-24h), respectively, before the ACR retention test. And CDP-choline (cc: 250 mg/kg), spermine (SM: 10 mg/kg), ${\alpha}-difluoromethylornithine$ (DO: 250 mg/kg), or aminoguanidine (AG: 100 mg/kg) was administered by one daily i.p. injection for 10 days. The ACR number $(13.7{\pm}1.0)$ obtained on the last training day was increased by 37.23% on the 20th day in the control rats. And the ACR increase was significantly suppressed by 5-ECS, ECS-3h, CC, or SM but was little affected by ECS-24h, DO, or AG. However, the 5-ECS induced impairment of ACR retention was significantly suppressed by AG, SM, and CC in the order of potency but was little affected by DFMO. And the ECS-3h induced impairment was moderately worsened by SM or AG. The acetylcholine (ACh) of the rat hypothalamus (HT), hippocampus (HC), and entorhinal cortex (EC) was markedly increased by CC and moderately increased by SM, but little affected by ECS-3h, ECS-24h, DO, or AG. But $5{\times}ECS$ slightly increased the ACh content. The brain putrescine (Pt) content was significantly increased by AG and little affected by CC, SM, or DO. But the $5{\times}ECS$ markedy decreased the brain Pt content, and the decrease was significantly suppressed by CC, SM, or AG. CC induced the marked increases of the spermidine (Sd) and spermine (Sm) contents of all the areas. SM increased the Sd contents of all the areas and the EC-Sm content. DO decreased the brain Sd and Sm contents. And AG increased the HT-Sd content and the Sm contents of all the brain areas. The $5{\times}ECS$ induced decrease of the HC-Sm content was suppressed by CC, SM and AG. These results suggest that the improving effect of aminoguanidine on the $5{\times}ECS$ induced impairment of ACR retention may be ascribed in part to its activity as a diamine oxidase inhibitor.

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Changes of Glutamate and Polyamine Levels of Hippocampal Microdialysates in Response to Occlusion of Both Carotid Arteries in Mongolian Gerbils (뇌허혈 손상에 있어서 해마-세포외액내 Glutamate와 Polyamine 농도의 변동에 관한 연구)

  • Shin, Kyung-Ho;Kim, Hyung-Gun;Choi, Sang-Hyun;Cho, So-Hyun;Chun, Yeon-Sook;Chun, Boe-Gwun
    • The Korean Journal of Pharmacology
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    • v.30 no.3
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    • pp.273-289
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    • 1994
  • Reversible brain ischemia was produced by occluding both common carotid arteries for 5 min, and the effects of aminoguanidine (AG), $DL-{\alpha}-difluoromethylornithine$ (DFMO), MK-801, and nimodipine (NM) on the ischemia induced changes of the polyamine, glutamate and acetylcholine levels in the hippocampus CA1 subfield and the specific $[^3H]\;MK-801$ binding to the hippocampus synaptosomal membranes were studied with a histological reference of the cresyl violet stained hippocampus. The basal putrescine level $(PT:\;74.4{\pm}8.8\;nM)$ showed a rapid increase (up to 1.7 fold) for 5 min of ischemia, remained significantly increased for 6 h, and then resumed the further increase to amount gradually up to about 3 fold 96 h after recirculation. However, the level of spermidine was little changed, and the spermine level showed a transient increase during ischemia followed by a sustained decrease to about 40% of the preischemic level after recirculation. The increase of PT level induced by brain ischemia was enhanced with AG or MK-801, but it was reduced by DFMO or NM. The basal glutamate level $(GT:\;0.90{\pm}0.l4\;{\mu}M)$ rapidly increased to a peak level of $8.19{\pm}1.14\;{\mu}M$ within 5 min after onset of the ischemia and then decreased to the preischemic level in about 25 min after recirculation. And NM reduced the ischemia induced increase of GT level by about 25%, but AG, DFMO and MK-801 did not affect the GT increase. The basal acetylcholine level $(ACh:\;118.0{\pm}10.5\;{\mu}M)$ did little change during/after brain ischemia and was little affected by AG or NM. But DFMO and MK-801, respectively, produced the moderate decrease of ACh level. The specific $[^3H]\;MK-801$ binding to the hippocampus synaptosomal membrane was little affected by brain ischemia for 5 min. The control value (78.9 fmole/mg protein) was moderately decreased by AG and MK-801, respectively but was little changed by DFMO or NM. The microscopic findings of the brains extirpated on day 7 after ischemia showed severe neuronal damage of the hippocampus, particularly CA1 subfield. NM and AG moderately attenuated the delayed neuronal damage, and DFMO, on the contrary, aggravated the ischemia induced damage. However, MK-801 did not protect the hippocampus from ischemic damage. These results suggest that unlike to the mode of anti-ischemic action of NM, AG might protect the hippocampus from ischemic injury as being negatively regulatory on the N-methyl-D-aspartate (NMDA) receptor function in the hippocampus.

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