• 생명과학회지
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• 제12권5호
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• pp.505-514
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• 2002

생쥐에서 최근 합성된 4가지 종류의 tropinone유도체들의 항경련 효과를 조사하기 위하여 pentylenetetrazole (PTZ) 및 Maximal Electroshock (MES)로 유발된 경련에 tropinone 유도체들이 경련상태에 미치는 효과를 관찰하였다. Troponine 유도체로는 화학구조가 다른 4가지 종류를 사용하였다(T-1:2,4-dipywolylmethenylnortropinone, T-2:2,L di phenylme thenylnortropinone, T-3 : 2,Ldifurfurylmetheny- Inortropinone, 74 : 2,4-dimetho xyphenylmethenylnortro- pinone). nZ 25 mg/kg을 복강 내로 투여 후 전신성 경련을 유발하였으며 tropinone 유도체를 전처치한 후 PTZ에 의한 경련의 변화를 관찰하였다. 대조군에 비하여 T-1과 T-2는 경련정도에 변화가 없었으나 T-3과 T-4는 유의하게 경련정도를 약화시켰다. PTZ에 의한 경련의 시작 시간은 T-4에서 유의하게 지연되어 T-4가 PTZ에 의한 경련에 항경련 효과가 있음을 나타내었다. MES로 경련을 유발한 경우에 있어서는 T-1이 경련정도를 유의하게 약화시켰으며 경련 후 회복시간도 T-1에서 가장 빨리 회복되는 특성을 보였다. 따라서 T-1이 MES에 의한 경련유발에 항경련 효과가 있음을 나타내었다. Troponine 유도체에 의한 경련 억제 효과와 경련과 동반되어 증가한다고 알려진 neuronal nitric oxide synthase (nNOS) 발현과의 관계를 알아보기 위하여 조직 단백질에서 Western blot을 하였다. 대조군에 비하여 PTZ 및 MES에 의해 경련을 유발한 생쥐에서 모두 해마부 및 전뇌피질부에서 nNOS가 증가하였다. Tropinone 유도체를 투여하지 않고 경련을 유발시킨 대조군에 비하여 tropinone 유도체를 투여한 군에서도 모두 nNOS의 발현이 해마부 및 전뇌피질부에서 증가되었다. MES로 경련을 유발한 생쥐에서 대조군에 비하여 T-1 및 T-4는 피질부에서 nNOS가 감소했으나 나머지군에서는 감소가 없었다. 이 상의 결과를 토대로 tropinone 유도체들은 경련유발의 자극 조건에 따라 항경련 효과가 다르게 나타났으며, PTZ유 발경련에서 2,4-dimethoxyphenylmethenylnortropinone의 항경련 효과가 가장 크고, MES 유발경련에서는 2,4-dipyrrolylmethenylnortropinone의 항경련 효과가 가장 크게 나타났다.

• The Korean Journal of Physiology and Pharmacology
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• 제18권3호
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• pp.269-278
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• 2014

Various antiepileptic drugs (AEDs) especially enzyme-inducing AEDs might be associated with increased vascular risk, through impairment of the endogenous antioxidative ability which may trigger oxygen-dependent tissue injury. Lamotrigine (LTG) a non-enzyme-inducing AED has scarce information regarding its effects on oxidative stress. The present study aimed to study the possible modulation of vascular risk factors of epileptogenesis by LTG, in a rat model of kindling seizure induced by pentylenetetrazole (PTZ). Four groups of male Wister rats were used; vehicle control group, PTZ group (alternate day PTZ, 30 mg/kg, i.p), LTG/PTZ group (LTG 20 mg/kg/day p.o and alternate day PTZ) and LTG group. The study period was 5 weeks. Lipoproteins and total homocysteine (tHcy), malondialdehyde (MDA) and reduced glutathione (GSH) were measured. Aortic endothelial function study and histopathological examination of the rats' brains, aortas and coronaries were conducted. Serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C), tHcy, MDA, GSH levels were significantly higher in epileptic rats than normal controls rats. A decrease in HDL-cholesterol with high atherosclerotic index was also demonstrated. The administration of LTG improved the PTZ-kindled seizures. It produced a significant decrease in TC, TG and LDL-cholesterol, MDA, aortic GSH and increase in HDL-cholesterol with no significant effect on serum GSH and tHcy levels. LTG improved endothelium-dependent relaxation, decreased hippocampal neurodegenerative changes and atherosclerotic changes of aortas and coronaries. LTG decreased seizures severity, hippocampal damage and improved vascular risk markers in this rat model of kindling seizures.

• BMB Reports
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• 제53권9호
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• pp.484-489
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• 2020

Epilepsy is a neurological disorder characterized by unpredictable seizures, which are bursts of electrical activity that temporarily affect the brain. Cereblon (CRBN), a DCAFs (DDB1 and CUL4-associated factors), is a well-established protein associated with human mental retardation. Being a substrate receptor of the cullin-RING E3 ubiquitin ligase (CRL) 4 complex, CRBN mediates ubiquitination of several substrates and conducts multiple biological processes. In the central nervous system, the large-conductance Ca²⁺-activated K⁺ (BK_Ca) channel, which is the substrate of CRBN, is an important regulator of epilepsy. Despite the functional role and importance of CRBN in the brain, direct injection of pentylenetetrazole (PTZ) to induce seizures in CRBN knock-out mice has not been challenged. In this study, we investigated the effect of PTZ in CRBN knock-out mice. Here, we demonstrate that, compared with WT mice, CRBN knock-out mice do not show the intensification of seizures by PTZ induction. Moreover, electroencephalography recordings were also performed in the brains of both WT and CRBN knockout mice to identify the absence of significant differences in the pattern of seizure activities. Consistently, immunoblot analysis for validating the protein level of the CRL4 complex containing CRBN (CRL4^Crbn) in the mouse brain was carried out. Taken together, we found that the deficiency of CRBN does not affect PTZ-induced seizure.

• Archives of Pharmacal Research
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• 제22권5호
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• pp.491-495
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• 1999

In order to examine the effects of N-substituted alkyl group on the anticonvulsant activities of N-Cbz-$\alpha$-aminoglutarimides as novel anticonvulsants with broad spectrum, a series of (R) or (S) N-Cbz-$\alpha$-amino-N-alkylglutarimides (1 and 2) were prepared from the corresponding (R) or (S) N-Cbz-glutamic acid and evaluated for the anticonvulsant activities in the maximal electroshock seizure (MES) test and pentylenetetrazol induced seizure(PTZ) test, including the neurotoxicity. The most potent compound in the MES test was (S) N-Cbz-$\alpha$-amino-N-methylglutarimide($ED_{50}$=36.3 mg/kg, PI=1.7). This compound was also most potent in the PTZ test ($ED_{50}$=12.5 mg/kg, PI=5.0). The order of anticonvulsant activities against the MES test as evaluated form $ED_{50}$ values for (R) series was N-methyl > N-H > N-ethyl > N-allyl ; for the (S) series N-methyl > N-H > N-ethyl > N-alkyl > N-isobutyl compound. Against the PTZ tests, the order of anticonvulsant activities showed similar pattern ; for the (R) series, N-methyl > N-H > N-ethyl > N-allyl ; for the (S) series N-methyl > N-H > N-ethyl > N-allyl > N-isobutyl compound. From the above results, N-substituted alkyl groups were though to play an important role for the anticonvulsant activities of N-Cbz-$\alpha$-amino-N-alkylgutarimides.

• Biomolecules & Therapeutics
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• 제3권3호
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• pp.199-204
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• 1995

Gastrodia elata is a medicinal plant which has been used as anticonvulsant in Korea, Japan and China. This study was conducted to examine the action mechanism of Gastrodia elata centering around the change of GABA and glutamic acid level in brain while observing the anticonvulsive effect in PTZ-induced seizure model. Seizures were reduced effectively by pretreatment of ether soluble part of methanol extract of Gastrodia elata. The pretreatment of ether soluble part inhibited not only the decrease of brain GABA level but also the increase of brain glutamic acid level observed in PTZ model of convulsive dose. Although there was not any change in glutamic acid level, the same development was also observed in the model of subconvulsive dose. From above results, it seems that the anticonvulsive component of Gastrodia elata is lipophilic, and its action mechanism is originated from both control action of GABA level and inhibition of glutaminergic neurotransmission.

• Archives of Pharmacal Research
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• 제19권3호
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• pp.248-250
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• 1996

In conclusion, a series of N-Cbz-.alpha.-amono-glutarimides (1a-f), combining common structures such as N-CO-C-N and cyclic imide in a single molecule, were prepared from the (R)- or (S)-N-Cbz-glutamic acid and evaluated for their anticonvulsant activities in MES and PTZ tests in order to develope new and broad spectrum anticonvulsant. In this study, N-Cbz-.alpha.-aminoglutarimides (1) except ac and af, showed significant anticonvulsant activity in both MES and PTZ tests enough to be recommended as promising new anticonvulsant drug candidates. Now we are continuing to investigate further anticonvulsant test (quantification)for these compounds and synthesize their analogues in order to develop more active anticonvulsant and define the structure activity relationship more precisely.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.764-768
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• 1998

In connection with the development of new anticonvulsant agents with a broad spectrum, we reported that N-Cbz-alpha-aminoglutarimides, combining common structures of othe r anticonvulsants such as N-CO-C-N and cyclic imides in a single molecule, showed significant anticonvulsant activities in the MES (maximal electroshock seizure) and PTZ (pentylenetetrazole induced seizure) tests. In these studies, a series of (R) and (S) N-alkyloxycarbonyl-alpha-aminoglutarimides 7a-7e and 8a-8e, which were substituted with various alkyloxycarbonyl group instead of Cbz group, were prepared from the corresponding (R) and (S) N-Cbz-glutamic acid 3 and 4, and were evaluated with their anticonvulsant activities against the MES and PTZ tests, including neurotoxicity, in order to define the effect of N-alkyloxycarbonyl group on the anticonvulsant activities of N-alkyloxycarbonyl-${\alpha}$-aminoglutarimides. Among them, (S)N-4-nitrobenzyloxycarbonyl-${\alpha}$-amino-N-methylglutarimide 8e was the most active in MES ($ED_{50}$=35.6mg/kg, PI=2.7) and PTZ tests ($ED_{50}$=15.6, PI=6.1). Interestingly, (R) and (S) N-4-nitrobenzyloxycarbonyl-${\alpha}$-amino-N-methylglutarimide 7e and 8e and (R) N-phenoxycarbonyl-${\alpha}$-amino-N-methylglutrimide 7d showed significant anti-convulsant activities in both the MES and PTZ tests and other compounds showed anticonvulsant activities in only the PTZ test. In addition, it was found that their anticonvulsant activities were dependent on their stereochemistries and N-substituted alkyloxycarbonyl groups.

• Archives of Pharmacal Research
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• 제27권3호
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• pp.273-277
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• 2004

In previous studies for the development of new anticonvulsants, we found that N-Cbz-$\alpha$-amino-N-alkylsuccinimides exhibited significant anticonvulsant activities in the Maximal electroshock seizure (MES) and Pentylenetetrazole induced seizure (PTZ) tests, and also their anticonvulsant activities were dependent on the N-alkyl substituents existent in their structures. Based on these estimations, N-Cbz-$\alpha$-amino-N-hydroxysuccinimide and various N-Cbz-$\alpha$-amino-N-alkoxysuccinimides were prepared in order to develop more active anticonvulsants and to examine the effects of N-hydoxy or N-alkoxy groups on their anticonvulsant activities. The (R)-or (S)-N-Cbz-$\alpha$-amino-N-hydroxysuccinimide and N-Cbz-$\alpha$-amino-N-alkoxysuccinimides were prepared from the corresponding (R)-or (S)-N-Cbz-aspartic acid through the known synthetic procedures. Their anticonvulsant activities in the MES and PTZ test were evaluated. All of these compounds except 3a showed significant anticonvulsant activities against the PTZ test, but these compounds were not active in the MES test. The most active compound in the PTZ test was (R)-N-Cbz-$\alpha$-amino-N-benzyloxysuccinimide (ED$_{50}$=62.5 mg/kg). In addition, the anti-convulsant activities of these compounds were dependent on their N-substited groups. The order of anticonvulsant activity against the PTZ test, as judged from the ED50 values for (R) series was N-benzyloxy > N-hydroxy > N-isopropoxy > N-methoxy > N-ethoxy; for the (S) series N-ethoxy > N-benzyloxy > N-methoxy > N-isopropoxy.y.

• Archives of Pharmacal Research
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• 제27권2호
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• pp.151-155
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• 2004

In our previous studies for the development of new anticonvulsant of broad spectrum, we found that N-cbz-$\alpha$-aminoglutarimides showed significant anticonvulsant activities of broad spectrum enough to be recommended for the new anticonvulsants and their anticonvulsant activities were dependent on their imide substituent groups. Based on these results, various N-cbz--$\alpha$-amino-N-alkoxyglutarimides, where the imide N-H was substituted with the hydroxy and alkoxy group, were prepared and evaluated for their anticonvulsant activities using the Maximal electroshock seizure (MES) and Pentylenetetrazole induced seizure (PTZ) tests and also the rotorod test. A series of (R) or (S)-N-cbz--$\alpha$-amino-N-alkoxyglutarimides could be prepared from the corresponding (R) or (S)-N-cbz-glutamic acid following the usual synthetic procedure. Among them, (R)-N-cbz--$\alpha$-amino-N-hydroxyglutarimide ($ED_{50}$=86.25 mg/kg) was most active in the MES test. In the case of the PTZ test, (R)-N-cbz--$\alpha$-amino-N-benzyloxyglutarimide ($ED_{50}$= 62.5 mg/kg) was most active. Among the tested compounds, 2a-c, 3a, and 3b showed anticonvulsant activities in the MES and PTZ test. All of the tested compounds, except 2f and 3f, showed significant anticonvulsant activities in the MES or PTZ test. In addition, the neurotoxicities of these compounds were comparable to other anticonvulsant drugs.

• Archives of Pharmacal Research
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• 제20권1호
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• pp.53-57
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• 1997

For the purpose of defining the effects of the N-substituted alkyl groups on the anticonvulsant activities of N-Cbz-.alpha.-aminosuccinimides, various (R)- and (S)-N-alkyl substituted N-Cbz-.alpha.-aminosuccinimides (1 and 2) were prepared from the corresponding (R)- and (S)-N-Cbz-aspartic acid by using known reaction and were evaluated the anticonvulsant activies in the MES and PTZ tests, including their neurotoxicities. The most active compound in the MES test was (R)N-Cbz-.alpha.-amino-N-methylsuccinimide (1b) $(ED_{50}=52.5 mg/kg, Pl=3.2)$. And in case of the PTZ test, (R)-N-Cbz-.alpha.-amino-N-ethylsuccinimide (1c) was the most active compound $(ED_{50}/=32.5mg/kg, Pl=3.1)$. The order of anticonvulsant activities of these compounds against the MES test, as judged from the ED_50values for the R series (1), was N-methyl > N-isobutyl > non-substituted > N-ethyl, N-allyl > N-benzyl compound; for the S series (2) N-methyl > N-altyl > non-substituted > N-isobutyl > N-ethyl > N-benzyl compound. The anticonvulsant activities in the PTZ tests of these compounds exhibited somewhat different pattern ; for the R series (1) Nethyl > N-methyl > N-isobutyl> non-substituted > N-allyl > N-benzyl compound in order of decreasing activity; for S series (2) N-ethyl > N-allyl, non-substituted > N-isobutyl > N-methyl > N-benzyl compound in order of decreasing activity.