• Biomolecules & Therapeutics
• /
• 제26권3호
• /
• pp.274-281
• /
• 2018

A previous study in humans demonstrated the sustained inhibitory effects of donepezil on acetylcholinesterase (AChE) activity; however, the effective concentration of donepezil in humans and animals is unclear. This study aimed to characterize the effective concentration of donepezil on AChE inhibition and impaired learning and memory in rodents. A pharmacokinetic study of donepezil showed a mean peak plasma concentration of donepezil after oral treatment (3 and 10 mg/kg) of approximately $1.2{\pm}0.4h$ and $1.4{\pm}0.5h$, respectively; absolute bioavailability was calculated as 3.6%. Further, AChE activity was inhibited by increasing plasma concentrations of donepezil, and a maximum inhibition of $31.5{\pm}5.7%$ was observed after donepezil treatment in hairless rats. Plasma AChE activity was negatively correlated with plasma donepezil concentration. The pharmacological effects of donepezil are dependent upon its concentration and AChE activity; therefore, we assessed the effects of donepezil on learning and memory using a Y-maze in mice. Donepezil treatment (3 mg/kg) significantly prevented the progression of scopolamine-induced memory impairment in mice. As the concentration of donepezil in the brain increased, the recovery of spontaneous alternations also improved; maximal improvement was observed at $46.5{\pm}3.5ng/g$ in the brain. In conclusion, our findings suggest that the AChE inhibitory activity and pharmacological effects of donepezil can be predicted by the concentration of donepezil. Further, $46.5{\pm}3.5ng/g$ donepezil is an efficacious target concentration in the brain for treating learning and memory impairment in rodents.

• Journal of Animal Science and Technology
• /
• 제47권2호
• /
• pp.187-194
• /
• 2005

Telomeres locate at the end of chromosomes and consist of a tandem repeat sequence of $(TIAGGG)^{n}$ and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. This study was carried out to analyze the amount of telomeres and telomerase activity of chicken cells during embryonic and developmental stages. The whole embryos and prenatal tissues such as brain, heart, liver, kidney and testis at different developmental stages were obtained from Korean Native Chicken. The amount of telomeres on embryonic cells was analyzed by quantitative fluorescence in situ hybridization (Q-FISH) techniques using the chicken telomeric DNA probe. Telomerase activity was measured by telomeric repeat amplification protocol (TRAP) assay. Results indicated that the amounts of telomeric DNA on the most embryonic cells were gradually decreased during ontogenesis. Furthermore, the quantity of telomeres was quite different among embryonic tissues according to developmental origin. The relative amount of telomeres has more in regenerative cells such as embryonic disc and testicular cells than in non-regenerative cells such as liver, brain, heart and kidney cells. Telomerase activity was also highly detectable in most chicken cells at early embryonic stages. After 9 days of incubation, however, the telomerase activitie W

• 한국환경농학회지
• /
• 제6권2호
• /
• pp.77-83
• /
• 1987

유기인계(有機燐系) 살충제인 phorate 가 병아리의 Acetylcholin esterase 활성(活性) 저해(沮害)에 미치는 영향(影響)을 조사한 결과(結果)는 다음과 같았다. Phorate와 그 대사물(代謝物)에 대(對)한 AChE 및 ChE 활성(活性)의 $I_{50}$값은 phosphorothiolate형(型)(표현불가)이 phosphorodithiolate형(型)(표현불가)보다 약(約) $700{\sim}2500$배(培) 낮았으며, 측쇄(側鎖)의 산화(酸化) 상태별(狀態別)로 보면 sulfide>sulfoxide>sulfone의 순(順)으로 $I_{50}$값이 낮은 경향(傾向)이었다. 병아리에 대(對)한 phorate의 급성경구독성(急性經口毒性)은 1.02mg/kg 이었다. Phorate를 급성경구독성(急性經口毒性) $LD_{50}$값 이하(以下)로 경구(經口) 투여(投與)하였을 때 투여(投與) 후(後) 초기(初期)에는 혈장(血漿) ChE 활성(活性)이 뇌(腦) AChE 활성(活性)보다 더 크게 저해(沮害)되었으나, 효소활성(酵素活性)의 회부(回復)은 뇌(腦) AChE 보다 혈장(血漿) ChE 가 더 빠른 경향(傾向)을 보였다.

• BMB Reports
• /
• 제32권3호
• /
• pp.294-298
• /
• 1999

Myo-inositol monophosphate phosphatase is a key enzyme in the phosphoinositide cell-signaling system. Incubation of myo-inositol monophosphate phosphatase from porcine brain with N-bromosuccinimide (NBS) resulted in a time-dependent loss of enzyme activity. The inactivation followed pseudo-first-order kinetics with the second-order rate constant of $3.8{\times}10^3\;M^{-1}min^{-1}$. The time course of the reaction was significantly affected by the substrate myo-inositol-1-phosphate, which afforded complete protection against the loss of catalytic activity. Spectrophotometric studies indicated that about one oxindole group per molecule of enzyme was formed following complete loss of enzymatic activity. It is suggested that the catalytic function of myo-inositol monophosphate phosphatase is modulated by the binding of NBS to a specific tryptophan residue at or near the substrate binding site of the enzyme.

• 한국전자통신학회논문지
• /
• 제13권2호
• /
• pp.481-486
• /
• 2018

본 논문에서는 음악적 자극이 인간의 수리적 두뇌활동에 미치는 영향을 조사하는 것을 목적으로 하여 피험자의 뇌파를 분석한 결과를 제시한다. 음악적 자극으로는 진정성향의 음악과 자극성향의 음악을 선정하였고, 피험자의 뇌파에서는 집중력과 상관성이 높은 SMR파와 중간 베타파를 분석하여 비교하였다. 본 논문의 실험결과에서는 음악적 자극과 동시에 과제를 수행할 때의 파워가 더 높게 관측되었고, 진정성향의 음악적 자극이 자극성향의 음악적 자극보다 인간의 집중력에 방해되지 않는 것으로 나타났다.

• Animal cells and systems
• /
• 제1권4호
• /
• pp.583-587
• /
• 1997

Incubation of an NADPH-dependent succinic semialdehyde reductase from bovine brain with N-bromosuccinimide (NBS) resulted in a time-dependent loss of enzyme activity. The inactivation followed pseudo-first-order kinetics with the second-order rate constant of $6.8\times{10}^3$ $M^-1$ $min^{-1}$. The inactivation was prevented by preincubation of the enzyme with substrate succinic semialdehyde, but not with coenzyme NADPH. There was a linear relation-ship between oxindole formation and the loss of enzyme activity. Spectro-photometric studies indicated that about one oxindole group per molecule of the enzyme was formed following complete loss of enzymatic activity. It is suggested that the catalytic function of succinic semialdehyde reductase is modulated by binding of NBS to a specific tryptophan residue at or near the substrate binding site of the enzyme.

• Journal of Microbiology and Biotechnology
• /
• 제33권9호
• /
• pp.1189-1196
• /
• 2023

This study proposed to demonstrate the neuroprotective effects of heat-killed Levilactobacillus brevis KU15152. Heat-killed L. brevis KU15152 showed antioxidant activity similar to that of Lacticaseibacillus rhamnosus GG, in terms of radical scavenging activity. To evaluate the neuroprotective effects, conditioned medium (CM) obtained by incubating heat-killed bacteria in intestinal cells (HT-29) was used through gut-brain axis. CM from L. brevis KU15152 protected neuroblastoma cells (SH-SY5Y) against H₂O₂-induced oxidative stress. Pretreatment with CM significantly alleviated the morphological changes induced by H₂O₂. Heat-killed L. brevis KU15152 showed an increased brain-derived neurotrophic factor (BDNF) expression in HT-29 cells. L. brevis KU15152-CM remarkably downregulated the Bax/Bcl-2 ratio, while upregulating the expression of BDNF and tyrosine hydroxylase (TH) in SH-SY5Y cells. Furthermore, L. brevis KU15152-CM reduced caspase-3 activity following H₂O₂ treatment. In conclusion, L. brevis KU15152 can be potentially used as food materials to avoid neurodegenerative diseases.

• Parasites, Hosts and Diseases
• /
• 제44권4호
• /
• pp.373-378
• /
• 2006

To evaluate whether iron concentration in TYM medium influence on hydrogenosomal enzyme gene expression and hydrogenosomal membrane potential of Trichomonas vaginalis, trophozoites were cultivated in iron-depleted, normal and iron-supplemented TYM media. The mRNA of hydrogenosomal enzymes, such as pyruvate ferredoxin oxidoreductase (PFOR), hydrogenase, ferredoxin and malic enzyme, was increased with iron concentrations in T. vaginalis culture media, measured by RT-PCR. Hydrogenosomal membrane potentials measured with $DiOC_6$ also showed similar tendency, e.g. T. vaginalis cultivated in iron-depleted and iron-supplemented media for 3 days showed a significantly reduced and enhanced hydrogenosomal membrane potential compared with that of normal TYM media, respectively. Therefore, it is suggested that iron may regulate hydrogenosomal activity through hydrogenosomal enzyme expression and hydrogenosomal membrane potential.

• 한국산학기술학회논문지
• /
• 제11권4호
• /
• pp.1436-1441
• /
• 2010

본 연구는 바둑 학습을 하는 아동들이 학습 전과 후에 뇌 기능에 미치는 영향에 관한 연구로 바둑 학습을 하는 J시 I 바둑학원 원생 20명과 바둑 학원을 다니지 않은 대조군 20명을 대상으로 바둑 학습 전 뇌파 측정은 2008년 10월 27일부터 11월 7일까지 실시하였으며, 바둑 학습 후 뇌파 측정은 2009년 11월 2일부터 4일까지 실시하였다. 연구의 결과로 두 집단의 활성지수와 정서지수에서 유의미한 차이를 보였다. 이는 바둑 학습이 아동들의 뇌의 활성화와 정서적 안정을 주는 데 긍정적인 영향을 미쳤다고 볼 수 있다.

• Journal of Nutrition and Health
• /
• 제32권3호
• /
• pp.239-247
• /
• 1999

With the increasing elderly population in Korea, dementia has become a mojor health problem in Korea. Several studies have been conducted on the association between dementia and dietary intake, especially vitamin E and vitamin C. The purpose of this study was to investigate the effect of vitamin E and vitamin C supplementation on the decrease in cognitive function induced by scopolamine(300mg/kg) in rats. Rats were divided into three groups : control, vitamin C, and vitamin E supplementation(2.4g Vit C or Vit E /100g diet) and fed the diets for 6 weeks. There were significant decreases in active avoidance response and brain acetylcholinesterase activity in the control group, but no significant differences were observed in the vitamin E and C groups after scopolamine treatment. Brain dopamine concentration of vitamin E and C groups was significantly higher than those of control group after scopolamine injection. The concentrations of brain norepinephrine also showed similar tendence, even though it was not statistically significant. These results indicate that vitamin E and vitamin C may protect against the cognitive function decrease induced by scopolamine. However, it is still unclear how vitamin E and C influence brain neurotransmitters and improve cognitive function. Further study is need to elucidate the role of vitamin E and C supplementation in the prevention of dementia.