• Korean Journal of Veterinary Research
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• v.11 no.1
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• pp.59-63
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• 1971

Current interest in ${\gamma}$-aminobutyric acid (GABA) has arisen from the convergence of several independent line of investigation leading to the demonstration that this and related substances are normal products of brain metabolism and that GABA has an important physiological action upon brain function as well as upon certain peripheral nervous structures. The interest for neurophysiologists has been enhanced by the importance of the discovery for the role of humoral mediator of synaptic transmission or regulator of neuronal activity in the central nervous system, particularly if it may shed some elight upon the nature of central inhibitory processes. In accordance with such an interest and importance, this work was performed in order to standardize the normal content as a preliminary investigation of so-called night active and daytime active animals GABA content in their brains when they are exposed to light and darkness. The method, through which the estimation has made in this work, was paper chromatographic method developed by Maynert and Klingman for the estimation of GABA content in animal tissues. The results obtained are summerized as follows: 1) GABA content in the cerebral cortex of house rat ranged from 90 to $310{\mu}g/gm$ of wet weight. 2) The content of GAGA ranging from 130 to $510{\mu}g/gm$ of wet weight was occurred from midbrain of the rat. 3) GABA content was ranged from 30 to $150 {\mu}g/gm$ of wet weight of the rat cerebellum. 4) The contents of fowl cerebral cortex, midbrain, and cerebellum are estimated as ranging 230-590, 250-620, $50-280{\mu}g/gm$ of wet weight, respectively. As a result, it may be concluded that among three brain tissues of both animals the midbrain is the highest region in GABA content. Fowl brain, on the other side, contains more higher GABA content than the house rat brain does.

• Environmental Analysis Health and Toxicology
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• v.7 no.1_2
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• pp.53-57
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• 1992

Amount of lead burden in a tissue reflects poisoning of lead in that tissue, so is the removal of lead directly connected to curement of lead poisoning. The purpose of present study was to investigate the relative effects of penicillamine and thiamine tetrahydrofurfuryl disulfide (TTFD) or thiamine propyl disulfide (TPD) in the removal of lead from rat brain tissue treated with excessive lead. Wistar rat pups of both sexes were used in this experiment. Within 1 day of parturition, experimental mothers nursing their pups as well as rat pups were given drinking water containing 0.2% lead acetate, TTFD 20mg/1.2 L (2 mg/kg/day), TPD 20 mg/1.2 L (2mg/kg/day), penicillamine 40 mg/1.2 L (40 mg/kg/day), 0.2% lead acetate+TTFD 20mg/1.2 L (2 mg/kg/day), 0.2% lead acetate+ TPD 20 mg/1.2 L (2 mg/kg/day) or 0.2% lead acetate+ penicillamine 40 mg/1.2 L (40 mg/kg/day) ad libitum, throughout the entire period of experiment. Rat pups in the control group received normal tap water. The animals were sacrificed by decapitation on the day when they become 2 or 8 weeks of age. Brains were dissected into five regions: telencephalon, diencephalon, midbrain, pons/medulla and cerebellum. The dissected brain tissues were lyophillized and then solubilized by acid mixture (nitric acid + sulfuric acid). Lead levels in the solubilized brain tissues were measured by the inductively coupled plasma. In lead-exposed rats, lead levels were significantly higher than those of control group in all brain legions, lead levels in brain regions of TTFD or TPD group were generally lower than those of control group. The simultaneous administration of lead with TTFD or TPD to animals caused significant decrement of lead from all brain regions. In the elimination of lead from brain regions, effectiveness of TTFD or TPD was equivalant to penicillamine.

• Biomolecules & Therapeutics
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• v.24 no.1
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• pp.99-107
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• 2016

Triclosan is an antimicrobial or sanitizing agent used in personal care and household products such as toothpaste, soaps, mouthwashes and kitchen utensils. There are increasing evidence of the potentially harmful effects of triclosan in many systemic and cellular processes of the body. In this study, we investigated the effects of triclosan in the survivability of cultured rat neural stem cells (NSCs). Cortical cells from embryonic day 14 rat embryos were isolated and cultured in vitro. After stabilizing the culture, triclosan was introduced to the cells with concentrations ranging from $1{\mu}M$ to $50{\mu}M$ and in varied time periods. Thereafter, cell viability parameters were measured using MTT assay and PI staining. TCS decreased the cell viability of treated NSC in a concentration-dependent manner along with increased expressions of apoptotic markers, cleaved caspase-3 and Bax, while reduced expression of Bcl2. To explore the mechanisms underlying the effects of TCS in NSC, we measured the activation of MAPKs and intracellular ROS. TCS at $50{\mu}M$ induced the activations of both p38 and JNK, which may adversely affect cell survival. In contrast, the activities of ERK, Akt and PI3K, which are positively correlated with cell survival, were inhibited. Moreover, TCS at this concentration augmented the ROS generation in treated NSC and depleted the glutathione activity. Taken together, these results suggest that TCS can induce neurodegenerative effects in developing rat brains through mechanisms involving ROS activation and apoptosis initiation.

• Journal of Ginseng Research
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• v.33 no.4
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• pp.294-304
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• 2009

Ginsenosides are among the most well-known traditional herbal medicines frequently used for the treatment of various symptoms in South Korea. The neuroprotective effects of ginsenoside $Rg_3$ (G-$Rg_3$) on cholesterol-oxide-(CO)-induced neurotoxicity were investigated through the analyses of rat brains. The recently accumulated reports show that ginseng saponins (GTS), the major active ingredients of Panax ginseng, have protective effects against neurotoxin insults. In the present study, the neuroprotective effects of G-$Rg_3$ on CO-induced hippocampal excitotoxicity were examined in vivo. The in-vitro studies using rat cultured hippocampal neurons revealed that G-$Rg_3$ treatment significantly inhibited CO-induced hippocampal cell death. G-$Rg_3$ treatment not only significantly reduced CO-induced DNA damage but also attenuated CO-induced apoptosis. The in-vivo studies that were conducted revealed that the intracerebroventricular (i.c.v.) pre-administration of G-$Rg_3$ significantly reduced i.c.v. CO-induced hippocampal damage in rats. To examine the mechanisms underlying the in-vitro and in-vivo neuroprotective effects of G-$Rg_3$ against CO-induced hippocampal excitotoxicity, the effect of G-$Rg_3$ on the CO-induced elevations of the apoptotic cells in cultured hippocampal cells was examined, and it was found that G-$Rg_3$ treatment inhibited CO-induced apoptosis. The histopathological evaluation demonstrated that G-$Rg_3$ significantly diminished the apoptosis in the hippocampus and also spared the hippocampal CA1, CA3, and dentate gyrus neurons. G-$Rg_3$ also significantly improved the CO-caused behavioral impairment. G-$Rg_3$ itself had no effect, however, on the CO-induced inhibition of succinate dehydrogenase activity (data not shown). These results collectively indicate the G-$Rg_3$-induced neuroprotection against CO in rat hippocampus. With regard to the wide use of G-$Rg_3$, this agent is potentially beneficial in treating CO-induced brain injury.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.96-96
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• 1995

It was recognized that lead intoxication reduces thiamine content in the brain of rat and this change produces the alterations of thiamine-related biochemical reactions. In the present study, it was tested whether the changes of myelin composition as well as seizure threshold induced by lead intoxication in rats may be related to these changes of thiamine status and thiamine related biochemical factors. Wistar rats were divided into five groups: Control group, Lead-treated group, Lead plus Thiamine-treated group, Thiamine-deficient group, Pyrithiamine-treated group. Each group was divided into three subgroups: 3, 7 and 16 week old group. Myelin protein and phospholipid, one of the compositions of myelin lipid, were measured in the myelin isolated from rat brain. Threshold of electric shock seizure was tested in each group. The amount of each myelin composition in lead-treated group and thiamine-deficient group was significantly lower than those of all the brains in control group, but recovery by supplementation with thiamine during lead intoxication was occurred only in the cerebellum of 3 week old animal. Thresholds of the electric shock seizure of lead treated group and thiamine deficient group in 3 and 7 week old rats were significantly lower than those of control group, while those of lead plus thiamine treated group were similar to those of control group.

• Biomolecules & Therapeutics
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• v.9 no.2
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• pp.88-95
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• 2001

(+)-Methamphetamine (METH) is a psychostimulant, which has been the most popular abused drug in Korea. The rewarding mechanism in METH abuse has been reported to be mediated by dopaminergic system. Recently, it has been reported that dopamine releaser (phentermine) plays a dominant role in the discriminative stimulus effects of METH, whereas 5-HT releaser (fenfluramine) can strongly modify METH self-administration. The present study is designed to assess the behavioral changes and the changes of the serotonin receptors in the brains of rats administered repeated of self-administered METH. The repeated administration of 1.0 mg/kg/day METH for 12 days increased locomotor activities, and there was no difference between i.v. and i.p. treatment. Rats had actively acquired METH self-administration for 3 weeks at 0.1 or 0.2 mg/kg/injection. Whereas, it was taken few days to acquire sucrose pellet self-administration. The binding of [$^3$H]-8-hydroxy-DPAT (5-H $T_{1A}$ receptors) and [$^3$H]-5-carboxytryptamine (5-H $T_{1B}$ receptors) to brain sections was examined. Both passive administration and self-administration of METH did not change significantly the serotonin receptors levels in hippocampus, striatum and nucleus accumbens. These results suggest that serotonin receptors may not change in the acquisition period of METH self-administration, and we are trying to investigate the serotonin receptors levels of brain in rats maintained of METH self-administration.n.n.

• The Journal of Dong Guk Oriental Medicine
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• v.11
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• pp.58-65
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• 2008

Objectives : BHT has been commonly used to treatment of brain disorders in Oriental clinic in Korea. The purpose of this study was to determine the inhibitory effect of modified BHT-C extract on the transient forcal cerebral ischemia in rats. Method : We prepared ischemic rats by the transient middle cerebral artery occlution(MCAO; 90 min occlusion and 144 h reperfusion) in rat brains. BHT-C extract (100 and 200 mg/kg, i.p.) was administered every day after the onset of MCAO until 6 day. Result : BHT-C extract increased survival rate of ischemic rats compared with vehicle-treated rats. BHT-C extract treated rats (100 and 200 mg/kg) were shown a significant reduction in infarct volume compared with vehicle-treated rats. Conclusions : These results suggest that BHT-C extract may contribute to its protective effects in brain ischemia through the reduction of brain infarction.

• BMB Reports
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• v.35 no.5
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• pp.443-451
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• 2002

Malonate is a three-carbon dicarboxylic acid. It is well known as a competitive inhibitor of succinate dehydrogenase. It occurs naturally in biological systems, such as legumes and developing rat brains, which indicates that it may play an important role in symbiotic nitrogen metabolism and brain development. Recently, enzymes that are related to malonate metabolism were discovered and characterized. The genes that encode the enzymes were isolated, and the regulation of their expression was also studied. The mutant bacteria, in which the malonate-metabolizing gene was deleted, lost its primary function, symbiosis, between Rhizobium leguminosarium bv trifolii and clover. This suggests that malonate metabolism is essential in symbiotic nitrogen metabolism, at least in clover nodules. In addition to these, the genes matB and matC have been successfully used for generation of the industrial strain of Streptomyces for the production of antibiotics.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.169.2-170
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• 2003

Erythropietin (EPO), a hematopoietic factor is also required for normal brain development, and its receptor is localized in brain. Therefore, it is possible that EPO could act as a neurotropic factor inducing differentiation of neurons. The present study, we therefore investigated whether EPO can increase differentiation of undifferentiated cortical neuron isolated from postneonatal (Day 1) rat brains and PC12 cell, undifferentiated dopaminagic cell line. EPO dose (1-100 U/ml) dependently increased cell differentiation and expression of differentiation marker gene (neurofilament and tyrosine hydroxylase) in both cells. (omitted)

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.146.1-146.1
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• 2002