• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.100.1-100.1
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• 2006

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.2
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• pp.57-64
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• 2007

Ischemic preconditioning (IPC) is known to protect the heart against ischemia/reperfusion (IR)-induced injuries, and regional differences in the mitochondrial antioxidant state during IR or IPC may promote the death or survival of viable and infarcted cardiac tissues under oxidative stress. To date, however, the interplay between the mitochondrial antioxidant enzyme system and the level of reactive oxygen species (ROS) in the body has not yet been resolved. In the present study, we examined the effects of IR- and IPC-induced oxidative stresses on mitochondrial function in viable and infarcted cardiac tissues. Our results showed that the mitochondria from viable areas in the IR-induced group were swollen and fused, whereas those in the infarcted area were heavily damaged. IPC protected the mitochondria, thus reducing cardiac injury. We also found that the activity of the mitochondrial antioxidant enzyme system, which includes manganese superoxide dismutase (Mn-SOD), was enhanced in the viable areas compared to the infarcted areas in proportion with decreasing levels of ROS and mitochondrial DNA (mtDNA) damage. These changes were also present between the IPC and IR groups. Regional differences in Mn-SOD expression were shown to be related to a reduction in mtDNA damage as well as to the release of mitochondrial cytochrome c (Cyt c). To the best of our knowledge, this might be the first study to explore the regional mitochondrial changes during IPC. The present findings are expected to help elucidate the molecular mechanism involved in IPC and helpful in the development of new clinical strategies against ischemic heart disease.

• Perspectives in Nursing Science
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• v.2 no.1
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• pp.61-75
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• 2005

Physical and psychological events can produce stress response in various degrees. Stress affects many aspects of physiology including both brain and peripheral elements which is represented as hypothalamus-pituitary-adrenal axis. Brain elements consist of corticotropin-releasing hormone(CRH), locus ceruleus(LC)-norepinephrine(NE)/autonomic system. Peripheral elements include pituitary-adrenal axis and the autonomic nervous system, which coordinate the stress response. Current trend of the stress researches is emphasizing the mechanisms of the stress response which is adaptive or become maladaptive. This review introduces 1) the concepts of stress, 2) physiological and behavioral aspects of stress responses, 3) the consequences of stress response, 4) the measurements of stress and 5) stress management for those interested in stress research.

• ALGAE
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• v.39 no.1
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• pp.17-30
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• 2024

Red macroalga Pyropia yezoensis is a high valuable cultivated marine crop. Its acclimation to cold stress is especially important for long cultivation period across winter in coasts of warm temperate zone in East Asia. In this study, the response of P. yezoensis thalli to low temperature was analyzed on physiology and transcriptome level, to explore its acclimation mechanism to cold stress. The results showed that the practical photosynthesis activity (indicated by Φ_PSII and qP) was depressed and pigment allophycocyanin content was decreased during the cold stress of 48 h. However, the F_v/F_m and non-photochemical quenching increased significantly after 24 h, and the average growth rate of thalli also rebounded from 24 to 48 h, indicating a certain extent of acclimation to cold stress. On transcriptionally, the low temperature promoted the expression of differentially expressed genes (DEGs) related to carbohydrate metabolism and energy metabolism, while genes related to photosynthetic system were depressed. The increased expression of DEGs involved in ribosomal biogenesis and lipid metabolism which could accelerate protein synthesis and enhance the degree of fatty acid unsaturation, might help P. yezoensis thallus cells to cope with cold stress. Further co-expression network analysis revealed differential expression trends along with stress time, and corresponding hub genes play important roles in the systemic acquired acclimation to cold stress. This study provides basic mechanisms of P. yezoensis acclimation to cold temperature and may aid in exploration of functional genes for genetic breeding of economic macroalgae.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.479-491
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• 1998

In order to know the pathogenesis of adult respiratory distress syndrome (ARDS) in association with the oxidative stress by neutrophils, the role of platelet activating factor (1-0-alkyl-2-acetyl-snglycero-3-phosphocholine, PAF) was investigated during acute lung injury induced by interleukin- $1{\alpha}$ (IL-1) in rats. An insufflation of IL-1 into the rat's trachea increased the acetyltransferase activity in the lung and the increase of PAF content was followed. As evidences of acute lung injury by neutrophilic respiratory burst, lung leak index, myeloperoxidase activity, numbers of neutrophils in the bronchoalveolar lavage fluid, neutrophilic adhesions to endothelial cells and NBT positive neutrophils were increased after IL-1 treatment. In addition, a direct instillation of PAF into the trachea caused acute lung leak and the experimental results showed a similar pattern in comparison with IL-1 induced acute lung injury. For the confirmation of oxidative stress during acute lung leak by IL-1 and PAF, a histochemical electron microscopy was performed. In IL-1 and PAF treated lungs of rats, the deposits of cerrous perhydroxide were found. To elucidate the role of PAF, an intravenous injection of PAF receptor antagonist, WEB 2086 was given immediately after IL-1 or PAF treatment. WEB 2086 decreased the production of hydrogen peroxide and the acute lung leak. In ultrastructural study, WEB 2086 mitigated the pathological changes induced by IL-1 or PAF. The nuclear factor kappa B (NFkB) was activated by PAF and this activation was inhibited by WEB 2086 almost completely. Based on these experimental results, it is suggested that the PAF produced in response to IL-1 through the remodeling pathway has the major role for acute lung injury by neutrophilic respiratory burst. In an additional experiment, we can also come to conclude that the activation of the NFkB by PAF is thought to be the fundamental mechanism to initiate the oxidative stress by neutrophils causing release of proinflammatory cytokines and activation of phospholipase $A_2$.

• Plant Biotechnology Reports
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• v.5 no.1
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• pp.19-25
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• 2011

Tocopherols belong to the plant-derived poly phenolic compounds known for antioxidant functions in plants and animals. Activation of mitogen-activated protein kinases (MAPK) is a common reaction of plant cells in defense-related signal transduction pathways. We report a novel non-antioxidant function of ${\alpha}$-tocopherol in higher plants linking the physiological role of tocopherol with stress signalling pathways. Pre-incubation of a low concentration of $50{\mu}M$ ${\alpha}$-tocopherol negatively interferes with MAPK activation in elicitor-treated tobacco BY2 suspension culture cells and wounded tobacco leaves, whereas pre-incubated BY2 cells with ${\alpha}$-tocopherol phosphate did not show the inhibitory effect on stimuli-induced MAPK activation. The decreased MAPK activity was neither due to a direct inhibitory effect of ${\alpha}$-tocopherol nor due to the induction of an inhibitory or inactivating activity directly affecting MAPK activity. The data support that the target of ${\alpha}$-tocopherol negatively regulates an upstream component of the signaling pathways that leads to stress dependent MAPK activation.

• Journal of Plant Biotechnology
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• v.38 no.2
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• pp.151-161
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• 2011

Plant proteomics is the large-scale studies of proteins, particularly on their structures and functions, governed by the physiological metabolism of plant cells. With the development of techniques and strategies in proteomics, proteomics approach is moving forward in systems biology handling sophisticated components of major signaling and biochemical pathways in plants responding to their environment. In Korea, pioneers in plant proteomics are trying to catch up with global trends in plant proteomics; these researchers are not only improving existing techniques in protein extraction but also developing new techniques in proteomics context. In the hot field of abiotic and biotic stress proteomics, 29 and 9 out of 74 papers have been published during the review period from 2005 to 2010, respectively. This present review article provides an overview on the output of Korean plant proteomers while paying special attention to both abiotic and biotic stress proteomics.

• Toxicological Research
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• v.34 no.1
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• pp.41-48
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• 2018

The efficacy of highly active antiretroviral therapy (HAART) has led to an increase demand for therapeutic use, thereby necessitating investigation into drug toxicity. This study was designed to investigate the in vivo effects of HAART on sperm parameters and testicular oxidative stress in lean and obese rats. Wistar rats (males, n = 40, weighing 180~200 g) were assigned randomly into 4 groups and treated accordingly for 16 weeks as follows: Control (C): lean group fed with standard rat chow; Diet induced obesity (DIO): obese animals fed a high caloric diet; C + ART: lean animals treated with HAART; DIO + ART: obese animals treated with HAART. An antiretroviral drug combination of Tenofovir, Emtricitabine and Efavirenz at a dose of 17, 26 and 50 mg/kg/day was administered for the latter 6 weeks via jelly cube feeding. At the end of the experimental period, sperm analysis was performed on sperm collected from the caudal epididymis, while the testis was homogenized for antioxidant enzyme and lipid peroxidation assays. Results showed that HAART significantly decreased sperm motility (p < 0.05) in both lean and obese animals, and viability (p < 0.05) in the DIO group. Testicular glutathione, catalase and superoxide dismutase were significantly decreased (p < 0.05), while Thiobarbituric acid reactive substances (TBARS) levels were significantly increased (p < 0.05) when the DIO+ART group was compared to Control group. Thus, the decreased sperm qualities associated with HAART might be as a result of increased testicular oxidative stress prominent in obese animals.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.1
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• pp.113-125
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• 2023

It has been reported that stressful events in early life influence behavior in adulthood and are associated with different psychiatric disorders, such as major depression, post-traumatic stress disorder, bipolar disorder, and anxiety disorder. Maternal separation (MS) is a representative animal model for reproducing childhood stress. It is used as an animal model for depression, and has well-known effects, such as increasing anxiety behavior and causing abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis. This study investigated the effect of MS on anxiety or aggression-like behavior and the number of GABAergic neurons in the hippocampus. Mice were separated from their dams for four hours per day for 19 d from postnatal day two. Elevated plus maze (EPM) test, resident-intruder (RI) test, and counted glutamic acid decarboxylase 67 (GAD67) or parvalbumin (PV) positive cells in the hippocampus were executed using immunohistochemistry. The maternal segregation group exhibited increased anxiety and aggression in the EPM test and the RI test. GAD67-positive neurons were increased in the hippocampal regions we observed: dentate gyrus (DG), CA3, CA1, subiculum, presubiculum, and parasubiculum. PV-positive neurons were increased in the DG, CA3, presubiculum, and parasubiculum. Consistent with behavioral changes, corticosterone was increased in the MS group, suggesting that the behavioral changes induced by MS were expressed through the effect on the HPA axis. Altogether, MS alters anxiety and aggression levels, possibly through alteration of cytoarchitecture and output of the ventral hippocampus that induces the dysfunction of the HPA axis.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2011.11a
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• pp.76-77
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• 2011