• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.327-332
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• 2001

In recent years, experimental evidence have been suggested that melatonin has either contractive or relaxing effects on the vascular smooth muscle in vitro. But the effect of melatonin on the cardiovascular system in vivo had been emphasized about the hypotensive effect. In this work, we found not only hypotensive effect but also hypertensive effect of melatonin in rats and attempted to determine the mechanism of these effects elicited by melatonin. Regadless of concentration, melatonin(0.002~5 mg/kg) produced increase in mean blood pressure (MBP) in 36% (54/150 cases) and decrease in mean blood pressure in 64%(96/150 cases). As a whole melatonin caused an increase or a decrease in MBP without compensatory decrease or increase in heart rate. The melatonin-induced hypertension was abolished by the pretreatment of phenoxybenzamine, a ${\alpha}$-adrenoceptor antagoninst. The melatonin-induced hypotension was abolished by the pretreatment of propranolol, a ${\beta}$-adrenoceptor antagonist, ODQ, a NO-sensitive guanylate cyclase inhibitor, or nifedipine, a L-type $Ca^{2+}$ channel blocker, but not by bilateral cervical vagotomy. The results indicate that melatonin-induced hypertension may be related to ${\alpha}$-adrenoceptor stimulation and melatonin-indued hypotension may be related to ${\beta}$-adrenoceptor stimulation, inhibition of $Ca^{2+}$ channel and/or activation of guanylate cyclase.

• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.417-423
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• 2018

Extracellular interleukin 1 alpha (IL-$1{\alpha}$) released from keratinocytes is one of the endpoints for in vitro assessments of skin irritancy. Although cells dying via primary skin irritation undergo apoptosis as well as necrosis, IL-$1{\alpha}$ is not released in apoptotic cells. On the other hand, active secretion has been identified in interleukin-1 receptor antagonist (IL-1ra), which was discovered to be a common, upregulated, differentially-expressed gene in a microarray analysis performed with keratinocytes treated using cytotoxic doses of chemicals. This study examined whether and how IL-1ra, particularly extracellularly released IL-1ra, was involved in chemically-induced keratinocyte cytotoxicity and skin irritation. Primary cultured normal adult skin keratinocytes were treated with cytotoxic doses of chemicals (hydroquinone, retinoic acid, sodium lauryl sulfate, or urshiol) with or without recombinant IL-1ra treatment. Mouse skin was administered irritant concentrations of hydroquinone or retinoic acid. IL-1ra (mRNA and/or intracellular/extracellularly released protein) levels increased in the chemically treated cultured keratinocytes with IL-$1{\alpha}$ and IL-$1{\beta}$ mRNAs and in the chemically exposed epidermis of the mouse skin. Recombinant IL-1ra treatment significantly reduced the chemically-induced apoptotic death and intracellular/extracellularly released IL-$1{\alpha}$ and IL-$1{\beta}$ in keratinocytes. Collectively, extracellular IL-1ra released from keratinocytes could be a compensatory mechanism to reduce the chemically-induced keratinocyte apoptosis by antagonism to IL-$1{\alpha}$ and IL-$1{\beta}$, suggesting potential applications to predict skin irritation.

• CELLMED
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• v.7 no.2
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• pp.8.1-8.7
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• 2017

Benign prostatic hyperplasia (BPH) is one of the major diseases of the urinary system in older men. WSY-0702 is the extracted from the traditional medicinal plant; Seoritae, and it has effects of anti-obesity, chronic cervical pain, and anti-oxidant. The present study aimed to investigate the therapeutic potential of WSY-0702 in the prevention and treatment of BPH. Several parameters including inflammatory mediators, hormones, and oxidative stress (OS) have been considered to play a role in the development of BPH. Prostate tissue damage and OS may lead to compensatory cellular proliferation with resulting hyperplastic growth. An in vitro study showed that proliferation inhibited the human prostate epithelial cell line RWPE-1 in a dose-dependent manner. In cell line, the cell cycle at the G2/M and G0/G1 phase and downregulated the expression of CyclineB1 (CCNB1) and CyclineD1 (CCND1). In addition, we measured the $H_2O_2$-induced OS damage using RWPE-1 cells. We examined the relative expression of protein involved in the regulation of prostate apoptosis: transforming growth factor (TGF)-${\beta}$, a negative growth factor able to induced prostate apoptosis under physiological conditions. These results suggest that WSY-0702 that can inhibit the growth of prostate epithelial cell by a mechanism that may involve arresting the cell cycle and downregulating CCNB1 and CCND1 expression. In addition, WSY-0702 exposure resulted in significant protective effects in $H_2O_2$-stressed PWPE-1 cells by reduction in TGF-${\beta}$ levels.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.341-347
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• 2013

This study was conducted to evaluate the effect of early diet dilution with 40% rice hull on growth performance, carcass characteristic and composition of meat-type ducks, and to reveal the possible mechanism for decreased body fat deposition. 160 1-day-old White Peking ducks with initial body weight of $44.5{\pm}1.0$ g were allotted to two treatments with 8 replicate pens per treatment and 10 ducks per pen (5 male and 5 female). Ducks were fed with the experimental starter diets diluted with 0% (control, RH0), 40% rice hull (RH40) during 8 to 14 d of age, respectively. Thereafter, all ducks were fed with grower diet. Ducks fed with RH40 diet from 8 to 14 d of age increased (p<0.05) feed intake, decreased (p<0.05) body weight, body weight gain and adjusted feed intake (excluded rice hull), abdominal fat, skin with fat, and fat content in carcass, and reduced (p<0.05) activities of hepatic malic dehydrogenase, glucose-6-phosphate dehydrogenase and fatty acid synthetase. When diet dilution was withdrawn in the re-fed period from 15 to 42 d of age, full compensatory growth of body weight, breast meat and leg meat weight were attained. However, ducks were still less (p<0.05) carcass fat content and showed continually lower (p<0.05) hepatic lipogenic enzyme activities at the market age in RH40 ducks than the control. These results indicated that diluting diet with 40% rice hull during 8 to 14 d of age might be a suitable method to improve feed efficiency, and to reduce carcass fat deposition in the production of meat-type ducks.

• YAKHAK HOEJI
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• v.32 no.1
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• pp.62-69
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• 1988

We have studied the effect of fasting on $Na^+$, $K^{+}-ATPase$ activities in the rat intestinal mucosa. Rats were fasted for $18{\sim}48hr$. Intestinal microsomal fraction was prepared by the method of Robinson and ATPase activities were determined by the modified method of Fiske and Subbarow. $Na^+$, $K^{+}-ATPase$ activity was not changed after fasting for 18 and 24 hr but significantly decreased after fasting for 48 hr. Fasting over 18 to 48 hr period had no effect on the $Mg^{++}-ATPase$. Thus, it may be concluded that 48 hr fasting has inhibitory effect on rat intestinal absorptive capabilities. In order to study the effect of Ginseng on the $Na^+$, $K^{+}-ATPase$ activities of the small intestine in chronic $K^{+}-depleted$ rats, rats were fed $K^{+}-depleted$ diets for 3 weeks and Ginseng ethanol extracts were administered orally for 3 weeks concomitantly. ATPase activity was measured by the same method as fasting group. $Na^+$, $K^{+}-ATPase$ activity in the $K^{+}-depleted$ diet group was increased and Ginseng ethanol extracts inhibited the increase of enzyme activity induced by $K^{+}-depleted$ diet. Thus, it may be suggested that increase in the intestinal $Na^+$, $K^{+}-ATPase$ activity of chronic $K^{+}-depleted$ group may be due to the compensatory mechanism and administration of Ginseng with $K^{+}-depleted$ diet may be associated with inhibition of increase in the enzyme activity of the $K^{+}-depleted$ group due to the prevention of the $K^+$ loss in the $K^{+}-depletion$.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.11a
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• pp.216-221
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• 1999

A mental task combined with noise background is an effective model of laboratory stress for study of psychophysiology of the autonomic nervous system (ANS). The intensity of the background noise significantly affects both a subjective evaluation of experienced stress level during test and the physiological responses associated with mental load in noisy environments. Providing tests of similar difficulties we manipulated the background noise intensity as a main factor influencing a psychophysiological outcome and the analyzed reactivity along withe the noise intensity dimension. The goal of this study was to identify the patterns of ANS responses and the relevant subjective stress scores during performance of word recognition tasks on the background of white noise (WN) of the different intensities (55, 70 and 85 dB). Subjects were 27 college students (19-24 years old). BIOPAC, Grass Neurodata System and AcqKnowlwdge 3.5 software were used to record ECG, PPG, SCL, skin temperature, and respiration. Experimental manipulations were effective in producing subjective and physiological responses usually associated with stress. The results suggested that the following potential autonomic mechanisms might be involved in the mediation of the observed physiological responses: A sympathetic activation with parasympathetic withdrawal during mild 55 and 70dB noise (featured by similar profiles) and simultaneous activation of sympathetic and parasympathetic systems during intense 85dB WN. The parasympathetic activation in this case might be a compensatory effect directed to prevent sympathetic domination and to maintain optimal arousal state for the successful performance on mental stress task. It should be mentioned that obtained results partially support Gellhorn's (1960; 1970) "tuning phenomenon" as a possible mechanism underlying stress response.

• Physical Therapy Korea
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• v.31 no.2
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• pp.123-130
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• 2024

Background: Weakness of gluteus medius (Gmed) is related with musculoskeletal disorders. Individuals who experience weakness in the Gmed may activate the tensor fasciae latae (TFL) as a compensatory mechanism. Application of isometric hip extension (IHE) with Thera-band may affect the activities of the Gmed, gluteus maximus (Gmax), and TFL, and the activity ratio of Gmed/TFL during side-lying hip abduction (SHA). Objects: To determine the influences of IHE during SHA on Gmed, Gmax, and TFL activities in participants with Gmed weakness. Methods: Three types of SHA exercises were performed: 1) traditional SHA in the frontal plane (SHA-T), 2) SHA with IHE applying Thera-band in the frontal plane (SHA-IHE), 3) and SHA with isometric hip flexion (IHF) applying Thera-band in the frontal plane (SHA-IHF). Results: SHA-IHE significantly showed higher Gmed and Gmax activities than SHA-T and SHA-IHF. SHA-IHF significantly showed higher activity of TFL than SHA-T or SHA-IHE. The activity ratio of Gmed/TFL was significantly higher in the SHA-IHE, SHA-T, and SHA-IHF, in that order. Conclusion: The SHA-IHE resulted in higher activities of Gmed, Gmax and a higher muscle ratio of Gmed/TFL.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.95-102
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• 1995

The pathogenesis of diabetic nephropathy is still not completely understood while renal disease is one of the most common disabling complications of diabetes. We, in the present study, investigated the possible involvement of oxidative stress in the development of diabetic nephropathy. To hasten the development of diabetic nephropathy, streptozotocin was injected to unilaterally nephrectomized rats (NEPH-STZ). Eight weeks later, NEPH-STZ rats developed severe hyperglycemia, proteinuria, and hypertension. The kidneys of these rats showed compensatory hypertrophy and mesangial expansion. In contrast, the rats with streptozotocin injection alone (STZ) did not increase urinary protein excretion. Nephrectomized non-diabetic rats (NEPH) developed increased urine protein excretion, but without prominent renal morphological changes. However, oxidation of renal cortical tissue protein significantly increased in all 3 groups of NEPH, STZ and NEPH-STZ in comparison to control rats (CONT). The result indicates the non-specificity of the oxidative tissue damage and suggests that the oxidative damage is hardly a sole mechanism leading to the development of the diabetic nephropathy. However, it would still be a contributing factor considering that the oxidative stress is a common final pathway mediating tissue damages in chronic diabetic complications and other serious illness.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.523-528
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• 1984

The small filefish, Rudarius ercodes, generally spawning from mid May to early October in the natural habitat, was exposed to various photoperiod and temperature regimes. These environmental effects on the gonad activity, regression and recrudescence were experimentally investigated based on the mechanism of reproductive cycle. Spawning season was initiated in the early spring with the gonad activated by long photoperiod(13L) and stimulated by compensatory temperature rising. Even when the gonad activated readily at the above critical daylength (12L to 13L)was kept back at the below if, it went on maturing. At the end of spawning period (mid September), since the shortening of daylength (12L) resulted in the gonad regression regardless of temperature, the short daylength might be related to the termination of spawning in situ. When the regressive gonad at the post spawning period was treated by the above 13L: $20^{\circ}C$ condition, it could recrudesce and bring forth even spawning. From this fact, the feasible control of annual reproductive cycle of small filefish was recognized. But even in the long daylength, the temperature above $28^{\circ}C$ was preventive of gonad maturation.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.105-115
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• 2006

The purpose of this study is to elucidate the mechanical characteristics of lower extremity joint movements at different walking speeds in obese people and suggest the very suitable exercise for obese person's own body weight and basic data for clinical application leading to medical treatment of obesity. This experimental subjects are all males between the ages of 20 and 30, who are classified into two groups according to Body Mass Index(BMI): one group is 15 people with normal body weight and the other 15 obese people. Walking speed is analysed at 3 different speeds ($1.5^m/s$, $1.8^m/s$, $2.1^m/s$) which is increased by $0.3^m/s$ from the standard speed of $1.5^m/s$. We calculated joint moments of lower extremity during stance phase through video recording and platform force measurement.Two-way ANOVA(Analysis of Variance, Mix) is applied to get the difference of moments according to walking speeds between normal and obese groups. Pearson's Correlation Analysis is applied to look into correlation between walking speeds and joint moments in both groups. Significance level of each experiment is set as ${\alpha}=.05$. As walking speed increases maximum ankle plantar flexion moment in the stance phase is smaller in obese group than in normal group, which is suggestive of weak toe push-off during terminal stance in obese group, and the highest maximum ankle plantar flexion moment in obese group during the middle speed walking($1.8^m/s.$). Maximum ankle dorsal flexion moment in obese group is relatively higher than in normal group and this is regarded as a kind of compensatory mechanism to decrease the impact on ankle when heel contacts the floor. Maximum knee flexion and extension moments are both higher in normal group with an increase tendency proportional to walking speed and maximum hip flexion and extension moments higher in obese group. In summary, maximum ankle plantar flexion moment between groups(p<.025), maximum knee moment not in flexion but in extension(p<.001) within each group according to increasing walking speed, and maximum hip flexion and extension moment(p<.001 and p<.004, respectively according to increasing walking speed are statistically significant but knee and hip moments between groups are not. Pearson correlation are different: high correlation coefficients in maximum knee flexion and extension moments, in maximum hip extension moment but not hip flexion, and in maximum ankle dorsal flexion moment but not ankle plantar flexion, in each group. We suspect that equilibrium imbalance develops when the subject increases walking speed and the time is around which he takes his foot off the floor.