• Journal of Oral Medicine and Pain
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• 제31권1호
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• pp.79-89
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• 2006

구강 내에 발생되는 질환의 대부분이 타액의 영향을 받는다는 사실과 타액에 영향을 주는 전신적인 요소 중에서도 스트레스가 중요하다는 것은 이미 잘 알려져 있으나, 스트레스가 타액선에 미치는 영향에 관해서는 자율신경에 의한 거시적 반응에 대하여만 소개가 되었을 뿐 세포수준의 미시적 변화에 대하여는 별다른 언급이 없었다.. 이에 본 연구에서는 다양한 스트레스 조건하에서 백서의 악하선이 어떠한 변화를 보이는지를 clusterin 의 발현양상을 관찰함으로써 유추해보고자 하였다. 부여할 스트레스 조건을 급성 구속스트레스와 만성 저강도 스트레스의 두 가지로 정하고 7주된 Sprague-Dawley계 웅성백서 51마리를 사용하여 정해진 기간동안 급성 구속스트레스와 만성 저강도 비예측성 스트레스 (CUMS)를 가한 후 희생하여 악하선을 절취하고 역시 면역조직화학법과 웨스턴 면역점적법을 이용하여 악하선에서 clusterin발현의 시간에 따른 변화를 관찰하였으며, 그 결과는 다음과 같다: 1. 급성 구속스트레스 군에서, Clusterin 이 발현된 모든 선포의 합은 1시간 군을 제외한 모든 실험군 (9시간, 24시간, 72시간, 120시간, 그리고 168시간 군) 에서 대조군에 비하여 유의성 있게 감소하는 경향을 보였다 (p<0.001). 2. 만성저강도스트레스 군에서, 대조군에 대한 clusterin이 발현된 모든 선포의 합은, 2주군(p<0.01)에서 대조군에 비하여 유의하게 증가되는 모습을 보여주었고, 4주군(p<0.01)과 5주군(p<0.001)에서 대조군에 비하여 유의성 있게 감소하는 경향을 보였다. 3. 만성 저강도 스트레스 실험에서 4주째까지는 대조군과 실험군간의 당선호도 차이에 있어서 유의한 변화가 보이지 않았으나, 5주째에 유의성 있는 감소를 나타내었다(p<0.001). 4. 만성 저강도 스트레스 부여군은 5주째 대조군에 비하여 유의성 있는 체중변화(p<0.001)를 보여주었으나, 수분섭취량의 변화는 유의성 있는 상관관계를 보여주지 못하였다. 5. 면역점적검사를 시행한 결과, 구속스트레스 군에서는 clusterin의 발현이 시간에 따라 일정하게 감소하는 것으로 표현되었고, CUMS 군에서는 2주째까지는 증가하다가 3주 이후부터 실험 전기간에 걸쳐 감소하는 것으로 나타났으며 이는 당선호도 및 몸무게 변화의 양상의 변화와 크게 다르지 않았다. 따라서 위의 실험결과를 놓고 볼 때, 타액선 clusterin의 발현이 급성과 만성에 관계없이 스트레스 부여 후에 감소하였지만, 다른 문헌에서 제안된 것처럼 clusterin 의 고갈에 의한 세포자사적 변화는 관찰되지 않았다. 따라서 향후 보다 강화된 강도의 급성스트레스를 부여하는 방법과 더 장기적으로 진행된 연구를 통하여 고강도 스트레스에서 clusterin의 발현감소와 함께 세포의 변성이나 자사가 초래되는지, 저강도 스트레스의 경우 장기간 시간이 경과함에 따라 원래의 상태에 가깝게 회복되는지, 다른 열 충격 단백질이나 세포 사멸 시에 나타나는 단백질들을 동시에 확인하여 보는 것이 필요할 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제28권3호
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• pp.230-239
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• 2020

Previous studies have shown disrupted synaptic plasticity and neural activity in depression. Such alteration is strongly associated with disrupted synaptic structures. Chronic stress has been known to induce changes in dendritic structure in the basolateral amygdala (BLA) and medial prefrontal cortex (mPFC), but antidepressant effect on structure of these brain areas has been unclear. Here, the effects of imipramine on dendritic spine density and morphology in BLA and mPFC subregions of stressed mice were examined. Chronic restraint stress caused depressive-like behaviors such as enhanced social avoidance and despair level coincident with differential changes in dendritic spine structure. Chronic stress enhanced dendritic spine density in the lateral nucleus of BLA with no significant change in the basal nucleus of BLA, and altered the proportion of stubby or mushroom spines in both subregions. Conversely, in the apical and basal mPFC, chronic stress caused a significant reduction in spine density. The proportion of stubby or mushroom spines in these subregions overall reduced while the proportion of thin spines increased after repeated stress. Interestingly, most of these structural alterations by chronic stress were reversed by imipramine. In addition, structural changes caused by stress and blocking the changes by imipramine were corelated well with altered activation and expression of synaptic plasticity-promoting molecules such as phospho-CREB, phospho-CAMKII, and PSD-95. Collectively, our data suggest that imipramine modulates stress-induced changes in synaptic structure and synaptic plasticity-promoting molecules in a coordinated manner although structural and molecular alterations induced by stress are distinct in the BLA and mPFC.

• The Korean Journal of Physiology and Pharmacology
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• 제17권5호
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• pp.441-446
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• 2013

In the present study, the anti-depressant like effect of methyl gallate (MG) isolated from the stem bark of Acer barbinerve was examined in ICR mice. Body weight (BDW) and blood glucose (BDG) levels significantly decreased in the repeated restraint stress (RRS) group (2 h/day for 14 days) compared to the no stress (NS) group. To examine the effect of MG on RS-induced BDW loss and hypoglycemia, MG (10 mg/kg) and the anti-depressant fluoxetine (10 mg/kg) were administered daily for 14 days. Orally administered MG and fluoxetine significantly attenuated the RS-induced BDW loss and hypoglycemia. Interestingly, MG administered mice showed increased BDG levels in the normal and glucose feeding condition. Chronic RS-subjected mice showed immobilized and depressed behaviors. The effect of MG on the depressed behaviors was evaluated using the tail-suspension test (TST) and the forced swimming test (FST). In both tests, RS-induced immobilized behaviors were significantly reversed in MG and fluoxetine administered groups. Taken together, MG significantly attenuated the RS-induced BDW loss, hypoglycemia, and depressed behaviors. Considering that decreased BDG levels (hypoglycemia) can cause depression, MG may exert its anti-depressant like effect by preventing hypoglycemia. Our results suggest that MG isolated from A. barbinerve can exert anti-depressant like effect, and could be used as a new and natural anti-depressant therapy.

• The Korean Journal of Physiology and Pharmacology
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• 제14권4호
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• pp.213-221
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• 2010

The hypothalamic-pituitary-adrenal (HPA) axis is the primary endocrine system to respond to stress. The HPA axis may be affected by increased level of corticotrophin-releasing factors under chronic stress and by chronic administration of monosodium glutamate (MSG). The purpose of this study was to investigate whether chronic MSG administration aggravates chronic variable stress (CVS)-induced behavioral and hormonal changes. Twenty-four adult male Sprague-Dawley rats, weighing 200~220 g, were divided into 4 groups as follows: water administration (CON), MSG (3 g/kg) administration (MSG), CVS, and CVS with MSG (3 g/kg) administration (CVS＋MSG). In addition, for the purpose of comparing the effect on plasma corticosterone levels between chronic stress and daily care or acute stress, 2 groups were added at the end of the experiment; the 2 new groups were as follows: naive mice (n=7) and mice exposed to restraint stress for 2 h just before decapitation (A-Str, n=7). In an open field test performed after the experiment, the CVS＋MSG group significant decrease in activity. The increase in relative adrenal weights in the CVS and CVS＋MSG group was significantly greater than those in the CON and/or MSG groups. In spite of the increase in the relative adrenal weight, there was a significant decrease in the plasma corticosterone levels in the CVS＋MSG group as compared to all other groups, except the naive group. These results suggest that impaired HPA axis function as well as the decrease in the behavioral activity in adult rats can be induced by chronic MSG administration under CVS rather than CVS alone.

• 대한수의학회지
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• 제44권4호
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• pp.607-613
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• 2004

Helicobacter pylori (H. pylori)-infection is an important pathogen of stomach cancer after chronic gastritis and ulceration in the stomach and duodenum. However, the virulences of H. pylori strains have not been well-defined between clinical isolates. This study was designed to establish water-immersion-restraint stress (WIRS) model in mongolian gerbil for comparison of pathogenicity of H. pylori strains. To determine an optimal duration time for WIRS model in gerbil, 5-week-old Mongolian gerbils were divided into different groups by WIRS duration time. After graded duration of WIRS, the macroscopic ulcer index (UI) was measured with the stomach and duodenum of sacrificed animal. There were no significant differences between male and female in same duration group. However, the UI increased significantly in a time-dependent fashion. The group of 6 hours-WIRS animals showed severe hemorrhage and ulceration in their stomach and duodenum. On the other hand, the very mild lesions induced in 2 hours-treated animals. Therefore, we determined an optimal duration time for WIRS model in gerbil as 4 hours. Thereafter, we evaluated whether this WIRS model in gerbil could be used as an useful tool for in vivo comparison of pathogenicity of H. pylori strains by enhancement of pathological severity in H. pylori-infected gerbils. Mongolian gerbils were divided into H. pyloriinfected and PBS-inoculated groups. Thereafter, they were divided again into 4 hours-WIRS and no WIRS subgroups. After treatment, the severity of pathological changes was evaluated in a same manner with previous duration-determining experiment. When the animals were exposed to WIRS, the UI was significantly higher in the infected group than in the uninfected group. These results suggested that the established gerbil-WIRS model in this study enhanced effectively the severity of pathogenic changes in the H. pylori-infected Mongolian gerbils and could be used as an useful tool for in vivo comparison of pathogenicity of H. pylori strains.

• 동의신경정신과학회지
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• 제30권3호
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• pp.209-220
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• 2019

Objectives: As a general emotion, everyone can temporarily experience depression, but depressive disorder is a disease that excessively affects daily life. Among the various causes of depression, the deficiency of monoamine-based neurotransmitters such as serotonin and epinephrine are considered significant. Thus, antidepressants that target monoamines are used frequently. However, side effects such as nausea, vomiting, insomnia, anxiety, and sexual dysfunction are observed. Thus, it is necessary to develop a new therapeutic agent with fewer side effects. In this study, we investigated the antidepressant effect of JG02, used to treat depression by normalizing the flow of qi (氣) in Korean medicine. Methods: C57BL/6 mice were selected and randomly divided into six groups: normal, control, amitriptyline, and JG02 (50, 125, 250 mg/kg), respectively. Except for normal, depression was induced by applying restraint stress at the same time for six hours daily for 14 consecutive days. Saline, amitriptyline or JG02 samples were orally administered two hours before applying the stress. After that, a forced swimming test and an open field test were performed. Additionally, serum corticosterone, serotonin mRNA, BDNF mRNA, and protein in the hippocampal region were measured and compared. Results: JG02 decreased immobility time rate in the FST and increased the zone transition number and travel distance in the OFT. Also, JG02 inhibited the release of serum corticosterone, and increased serotonin, BDNF gene expression, and BDNF protein in the hippocampus. Conclusions: In this study, JG02 showed significant antidepressant effects on the chronic restraint stress mice model. When further research is performed based on JG02, the development of a new antidepressant is considered highly possible.

• 동의생리병리학회지
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• 제34권2호
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• pp.88-96
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• 2020

Stauntonia hexaphylla (SH) and Vaccinium bracteatum (VB) are herbal extracts widely used in food and traditional herbal medicine, and have the ability to perform a wide range of biological activities. We aimed to investigate the effects of the SH and VB combination (SHVB) on mice models of chronic restraint stress (CRS) and pentobarbital-induced sleeping behaviors to elucidate its possible mechanisms of action. CRS-exposed mice treated with SHVB showed significantly decreased immobility time, increased swimming and climbing times in the forced swim test (FST), and increased locomotor activity in the open field test (OFT). SHVB decreased serum CORT levels, but enhanced brain monoamine neurotransmitters. SHVB significantly decreased the sleep latency and increased total sleep duration in pentobarbital-induced sleeping behavior in mice. SHVB showed inhibitory effect on 5-HT_2A receptor-mediated ERK1/2 phosphorylation. These results suggest that SHVB has antidepressant and hypnotic effects by regulating the 5-HT_2A receptor.

• 운동영양학회지
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• 제23권3호
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• pp.13-21
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• 2019

[Purpose] Chronic stress is a precipitating factor for depression, whereas exercise is beneficial for both the mood and cognitive process. The current study demonstrates the anti-depressive effects of regular exercise and the mechanisms linked to hippocampal neurogenesis. [Methods] Mice were subjected to 14 consecutive days of restraint, followed by 3 weeks of treadmill running, and were then subjected to behavioral tests that included the forced swimming and Y-maze tests. Protein levels were assessed using western blot analysis and newborn cells were detected using 5-bromo-2'-deoxyuridine (BrdU). [Results] Three weeks of treadmill running ameliorated the behavioral depression caused by 14 days of continuous restraint stress. The exercise regimen enhanced BrdU-labeled cells and class III β-tubulin levels in the hippocampal dentate gyrus, as well as those of thioredoxin-1 (TRX-1) and synaptosomal β2-adrenergic receptors (β2-AR) under stress. In vitro experiments involving treatment with recombinant human TRX-1 (rhTRX-1) augmented the levels of phospho-extracellular signal-regulated kinases 1 and 2 (ERK1/2), nuclear β-catenin, and proliferating cell nuclear antigens, which were previously inhibited by U0216 and FH535 (inhibitors of ERK1/2 and β-catenin/T cell factor-mediated transcription, respectively). The hippocampal neurogenesis elicited by a 7-day exercise regimen was abolished by a selective inhibitor of β2-AR, butoxamine. [Conclusion] These results suggest that TRX-1-mediated hippocampal neurogenesis by β2-AR function is a potential mechanism underlying the psychotropic effect of exercise.

• Journal of Ginseng Research
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• 제42권1호
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• pp.107-115
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• 2018

Background: Depression is one of the most commonly diagnosed neuropsychiatric diseases, but the underlying mechanism and medicine are not well-known. Although Panax ginseng has been reported to exert protective effects in various neurological studies, little information is available regarding its antidepressant effects. Methods: Here, we examined the antidepressant effect and underlying mechanism of P. ginseng extract (PGE) in a chronic restraint stress (CRS)-induced depression model in mice. Results: Oral administration of PGE for 14 d decreased immobility (depression-like behaviors) time in forced swim and tail suspended tests after CRS induction, which corresponded with attenuation of the levels of serum adrenocorticotropic hormone and corticosterone, as well as attenuated c-Fos expression in the amygdala. PGE enhanced messenger RNA expression level of brain-derived neurotrophic factor but ameliorated microglial activation and neuroinflammation (the level of messenger RNA and protein expression of cyclooxygenase-2 and inducible nitric oxide synthase) in the amygdala of mice after CRS induction. Interestingly, 14-d treatment with celecoxib, a selective cyclooxygenase-2 inhibitor, and $N_{\omega}$-nitro-L-arginine methyl ester hydrochloride, a selective inducible nitric oxide synthase inhibitor, attenuated depression-like behaviors after CRS induction. Additionally, PGE inhibited the upregulation of the nuclear factor erythroid 2 related factor 2 and heme oxygenase-1 pathways. Conclusion: Taken together, our findings suggest that PGE exerts antidepressant-like effect of CRS-induced depression by antineuroinflammatory and antioxidant (nuclear factor erythroid 2 related factor 2/heme oxygenase-1 activation) activities by inhibiting the hypothalamo-pituitary-adrenal axis mechanism. Further studies are needed to evaluate the potential of components of P. ginseng as an alternative treatment of depression, including clinical trial evaluation.

• 한국식품영양과학회:학술대회논문집
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• 한국식품영양과학회 2001년도 International Symposium on Food,Nutrition and Health for 21st Century
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• pp.22-37
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• 2001

Melatonin is secreted during the hours of darkness and is thought to influence the circadian and seasonal timing of a variety of physiological processes. Serotonin N-acetyltransferase (AA-NAT) which is found to be expressed in pineal gland, retina, and various tissues, catalyses the conversion of serotonin to N-acetylserotonin and is known as the rate-limiting enzyme in the biosynthetic pathway of melatonin. The compounds that modulate the activity of AA-NAT can be used to treat serotonin-and melatonin-related diseases such as insomnia, depression and seasonal affective disorders (SAD). Several assay methods have been developed by which to measure AA-NAT activity. We have also developed a simple, rapid and sensitive AA-NAT assay method that takes advantage of differences in the organic solubilities between acetyl CoA and N-acetyltryptamine. We screened modulators of AA-NAT activity from the water extracts of the medicinal plants. We found MNP1005 which strongly inhibited the activity of AA-NAT ($IC_{50}$=2.2$\mu$M). Enzyme inhibitory kinetic studies revealed that MNP1005 exhibited a noncompetitive inhibition toward tryptamine. The antidepressant effect of MNP1005 was investigated on behavioral despair test so called forced swimming test (FST). MNP1005 significantly increased swimming behavior by reducing immobility with treatment of 10 mg/kg when compared to the vehicle-treated control group (P < 0.05). This suggests that MNP1005 possesses antidepressant activity. The influence of chronic MNP1005 treatment on the expression of brain-derived neurotrophic factor (BDNF) was examined by in situ hybridization and Northern blot. Chronic treatment of MNP1005 blocked the downregulation of BDNF mRNA in the frontal cortex and other cortex regions in response to restraint stress.