• 제목/요약/키워드: thermoregulation

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The Hyperthermic Effect of Nitric Oxide in Central Nervous System

  • Jung, Jae-Kyung;Sohn, Uy-Dong;Lee, Seok-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.1
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    • pp.93-98
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    • 2001
  • The precise mechanism of set-point regulation in hypothalamus was not elucidated. Nitric oxide synthases(NOS) were detected in hypothalamus, however, the roles of NO in hypothalamus was not fully studied. So, we tested the effects of NO on body temperature because preoptic-anterior hypothalamus was known as the presumptive primary fever-producing site. NO donor sodium nitroprusside (SNP, 4 nmol, i.c.v.) elicited marked febrile response, and this febrile response was completely blocked by indomethacin (a cyclooxygenase inhibitor). But, ODQ (selective guanylate cyclase inhibitor, $50\;{\mu}g,$ i.c.v.) did not inhibit fever induced by SNP. The cyclic GMP analogue dibutyryl-cGMP $(100\;{\mu}g,\;i.c.v.)$ induced significant pyreses, which is blocked by indomethacin. $N^G-nitro-L-arginine$ methyl ester (L-NAME, non selective NOS inhibitor) inhibited fever induced by $interleukin-1{\beta}\;(IL-1{\bata},\;10\;ng,\;i.c.v.),$ one of endogenous pyrogens. These results indicate that NO may have an important role, not related to stimulation of soluble guanylate cyclase, in the signal pathway of thermoregulation in hypothalamus.

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Variation of Human Thermal Radiation Characteristics Applying Different Clothing Materials (의복 소재 변경에 따른 인체 열상신호 변화 특성)

  • Chang, Injoong;Bae, Ji-Yeul;Lee, Namkyu;Kwak, Hwykuen;Cho, Hyung Hee
    • Journal of the Korea Institute of Military Science and Technology
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    • v.22 no.5
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    • pp.644-653
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    • 2019
  • With the development of themal observatory device(TOD), thermal camouflage system has been applied not only to the weapon system but also to the combat suit for soldiers. In this paper, the characteristic of thermal radiation of human body depending on the clothing material properties was analyzed through numerical simulations. The bioheat equation with thermoregulatory model was solved to obtain the realistic surface temperature of human body and these results are combined with the emissivity of human skin and clothing in order to calculate the thermal signature from the human body. According to each thermal resistance of clothing, the optimal background radiance which makes contrast radiance intensity(CRI) be lowest is different. Also, the average CRI variation per thermal resistance change is about twice as much as the case of evaporative resistance change.

Preference for Heated Substrate in Captive River Cooters (Pseudemys concinna): A Potential Use for the Control of Invasive Populations

  • Kang, Hakyung;Borzee, Amael;Chuang, Ming-Feng;Jang, Yikweon
    • Animal Systematics, Evolution and Diversity
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    • v.37 no.1
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    • pp.9-14
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    • 2021
  • Invasive species threaten global biodiversity as well as human livelihood and much of the global lands are vulnerable to these threats. Numerous freshwater turtles from the northern hemisphere have been introduced in East Asian countries, including the Republic of Korea. Knowing turtle's behavioral ecology is valuable to manage introduced populations and a distinctive behavior is basking for behavioral thermoregulation. To understand the possibility of using basking to enhance trapping, we tested thermotaxis in the river cooter (Pseudemys concinna). Turtles were placed in an aquarium containing heated and non-heated mats under controlled water and air temperature, air humidity and light. We found that P. concinna stayed significantly longer on heated mats than on unheated control mats in 11 out of 18 trials, demonstrating that heat source is a potential attractant for P. concinna. We recommend the use of heat source to bait traps used for population control of invasive freshwater turtles.

Association of Cold-heat Pattern and Anthropometry/body Composition in Individuals Between 50-80 Years of Age (한열변증과 체형 및 체성분의 연관성 분석 - 50세 이상 장년 및 노년층을 대상으로)

  • Mun, Sujeong;Park, Kihyun;Lee, Siwoo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.4
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    • pp.209-214
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    • 2020
  • The association of cold-heat (CH) pattern and anthropometry/body composition has been suggested in that they are related to thermoregulation. We aimed to study the association of CH pattern and anthropometry/body composition. A total of 1479 individuals aged 50-80 years were included in the study, and their CH pattern were evaluated by a self-administered questionnaire. After adjustment for age and sex, the CH score were significantly correlated with weight, BMI (body mass index), body surface area, waist-hip ratio, fat free mass, body fat mass, body cell mass, intracellular water, extracellular water, and basal metabolic rate; however, the correlation coefficients were mostly low (0.15-0.24). The selected variables for predicting CH score were various according to the methods used for variable selection; however, the adjusted R-squared of the final models were all around 0.12. Thus the most parsimonious model could be the one that includes sex and BMI. In conclusion, various anthropometry and body composition indices were associated with CH pattern. Future studies are necessary to improve the performance of the prediction model.

Study on the Anthropometric and Body Composition Indices for Prediction of Cold and Heat Pattern

  • Mun, Sujeong;Park, Kihyun;Lee, Siwoo
    • The Journal of Korean Medicine
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    • v.42 no.4
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    • pp.185-196
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    • 2021
  • Objectives: Many symptoms of cold and heat patterns are related to the thermoregulation of the body. Thus, we aimed to study the association of cold and heat patterns with anthropometry/body composition. Methods: The cold and heat patterns of 2000 individuals aged 30-55 years were evaluated using a self-administered questionnaire. Results: Among the anthropometric and body composition variables, body mass index (-0.37, 0.39) and fat mass index (-0.35, 0.38) had the highest correlation coefficients with the cold and heat pattern scores after adjustment for age and sex in the cold-heat group, while the correlation coefficients were relatively lower in the non-cold-heat group. In the cold-heat group, the most parsimonious model for the cold pattern with the variables selected by the best subset method and Lasso included sex, body mass index, waist-hip ratio, and extracellular water/total body water (adjusted R2 = 0.324), and the model for heat pattern additionally included age (adjusted R2 = 0.292). Conclusions: The variables related to obesity and water balance were the most useful for predicting cold and heat patterns. Further studies are required to improve the performance of prediction models.

Trans-anethole Suppresses C2C12 Myoblast Differentiation

  • Mi-Ran Lee
    • Biomedical Science Letters
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    • v.29 no.3
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    • pp.190-200
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    • 2023
  • Skeletal muscle, essential for metabolism, thermoregulation, and immunity, undergoes myogenic differentiation that results in myotube formation. Trans-anethole (TA), the major constituent in essential oil produced by anise, star anise, and fennel, whose function in skeletal muscle has not yet been elucidated. Therefore, we investigated whether TA influenced muscle differentiation in mouse C2C12 myoblasts. Cells were induced to differentiate using a differentiation medium with or without TA (50 or 200 mg/mL) daily for 5 days. We measured myotube length and diameter after differentiation days 1, 3, and 5 and analyzed the expression of myogenic markers (myoblast determination protein 1, myogenin, myocyte enhancer factor 2, muscle creatine kinase, and myosin heavy chain) and atrophy-related genes (atrogin-1 and muscle ring finger-1 [MuRF-1]) using quantitative real-time PCR. Additionally, we observed the expression of total protein kinase B (Akt) and phosphorylated Akt (p-Akt) using western blotting. Our data showed that TA significantly induced the formation of smaller and thinner myotubes and reduced the myogenic factor expression. Furthermore, the atrogin-1 and MuRF-1 expression markedly increased by TA. Consistent with these findings, TA significantly decreased the expression of total Akt and p-Akt. Taken together, these results indicate that TA inhibits myogenic differentiation of C2C12 cells via reduction of both total Akt and p-Akt. Our findings may provide valuable insights into the impact of PAA on individuals at risk of muscle atrophy.

Metabolic Rate and Thermolabile Properties of Ognev's Great Tube-nosed Bat Murina leucogaster in Response to Variable Ambient Temperature

  • Choe, In-Ho;O, Yong-Geun;Jeong, No-Pal;Gang, Byeong-Ju;Sin, Hyeong-Cheol
    • Animal cells and systems
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    • v.2 no.1
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    • pp.49-53
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    • 1998
  • The winter-resident Korean bats, Murina leucogaster ognevi, show a circadian cycle of thermoregulation and locomotion in summer, as do other bat species in temperate regions. They are most active between dusk and dawn with body temperature (Tb) of 35-4OC, and are usually torpid in their roost sites for the rest of day with their Tb close to ambient temperature (Ta) of around 15C. The present study was conducted to determine thermogenic and thermolabile properties of the heterothermic bats that would influence their daily feeding activities and ultimately, their energy conservation strategy. Testing on active male Murina, resting metabolic rate (RMR, gauged by oxygen consumption rate) at the lower limit of thermoneutral zone (31C) was 2.0 L kq-1 h-1. The regression slope of RMR below the thermoneutral zone (an index of metabolic thermal sensitivity) was -0.38 L $kg^{-l} h^{-1} C^{-1}$. The metabolic rate at the roost Ta (15C) was 4.5 times the lowest RMR in the active state but becomes nearly zero in the torpid state. This implies that by being torpid during daytime (between dawn and dusk), the individual bats would save about 4.7 kcal each day in mid-summer. Interspecific comparisons of thermal metabolic response over a mass scale suggest that the smaller bats show a relatively higher metabolic rate in thermoneutral zone and a greater thermal sensitivity of metabolism, which follows the general principle seen in homeothermic metabolism. Thermolabile features in metabolic responses seem to be fairly common for these bats in conditions other than a fully active state. Types of thermolabile responses and their energetic significance are discussed.

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Effect of Clothing Habit on Thermoregulation of Body A Comparative Study of Skirt and Slacks (스커트와 슬랙스의 의복착용습관이 인체의 체온조절에 미치는 영향)

  • 최영희;이순원
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.6
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    • pp.983-991
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    • 1996
  • This study focusses on how the skirt or slacks wearing habit affects the female physiology in her daily life. The healthy female college students have been trained to wear either skirt (group A) or slacks (group B) from late August to early January in order to study the effects of clothing habit on thermoregulatory responses. Also, the themoregulatory responses have been compared the healthy students groups with a physical trained students group (group C) to examine the effects of clothing habit. The changes in body temperatures of students have been studied under the cool environmental condition (15$\pm$1$^{\circ}C$, 60$\pm$5% RH, 0.25 m/sec). The results were as follows: 1. Rectal temperature of the group A was 0.4$^{\circ}C$ lower at 36.9$^{\circ}C$ than that of the group B The groups A and B were found identical before the training, while the groups A and C were identical after the training. 2. Mean skin temperature of the group A was 1.2$^{\circ}C$ lower than that of the group B. The groups A and C were identical after the training. 3. The thermal sensation was reflected to be cool by the group A and to be cold by the group B. As for the humidity sensation, the group A felt average, whereas the group B reported between average and slightly humid. In the case of comfort sensation, the group A felt average, while the group B felt between average and slightly uncomfortable. In summary, the 18 weeks of training has provided the skirt group an improved acclimatization to the cold environment . This group also showed an insulative-hypothermic adapta lion in a cold ambient temperature, as was the case for the physical trained group. It is concluded that wearing a skirt for a long period of time can be helpful to human body through gaining of thermoregulatory abilities.

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Quantitative Wear Training for the Improvement of Heat Tolerance in Summer (Part II) -Wear Training by Optimal Temperature Inside Clothing for Women in Their 20s- (여름철 내열성 증진을 위한 정량적 착의훈련의 효과 (제2보) -20대 여성의 의복내 온도를 지침으로-)

  • Lee, Hyo-Hyun;Choi, Jeong-Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.36 no.4
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    • pp.371-381
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    • 2012
  • This study investigates quantitative wear training effects and involved 15 participants from a previous study (part 1) in May to September 2009. Before wear training, the subjects' rectal temperature, skin temperature, heart rate, blood pressure and local sweating were measured for 1 hour in a climate chamber ($39{\pm}1^{\circ}C$, $65{\pm}5%RH$, 0.3m/s) to evaluate heat tolerance. Subsequently, the subjects were divided into 3 groups that consisted of 5 participants. Group N (control-group) dressed the participants so that they felt comfortable (or cool). Group W and MW where participants underwent regular wear training for 10 weeks (5 days a week a total of 50 times). The intensity of the wear training for the participants of group MW was stronger than that for group W. A heat-tolerance experiment was performed after wear training. The results were as follows: 1. The participants of groups W and MW felt more comfortable after wear training than before wear training in the case of warmer $T_{cl}$. However, no significant differences were observed before and after wear training for group N. 2. The heat tolerance of the participants of groups W and MW was higher after wear training than before wear training. However, no significant difference was noted in this regard for group N. 3. The results showed the wear training effect (based on quantitative guidelines). The results show that the predicted optimal temperature inside clothing can enhance heat tolerance.

Effects of Treadmill Exercise on Respiratory Moisture Losses in Goats of Different Breeds

  • Kasa, I.W.;Thwaites, C.J.;Hill, M.D.;Baillie, N.D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.6
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    • pp.842-844
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    • 2000
  • Changes in respiration rate (RR), rectal temperature (RT), respiratory moisture loss (RML), packed cell volume (PCV) and haemoglobin (Hb) were monitored in 2 adults female goats each of the Saanen (S) and Toggenburg (T) breeds during 60 min of exercise (walking at 3 km/h) on a moving-belt treadmill on each of 6 alternate days. A significant $time{\times}breed$ interaction was observed for RR; mean values in Sand T after 60 min of exercise were 130 and 223 /min ($p{\leq}0.01$). The observed time x breed interaction for RT indicated that S was less stressed by exercise than T; mean values after 60 min exercise were 40.4 and $40.8^{\circ}C$ respectively ($p{\leq}0.01$). For RML, the $day{\times}breed$ interaction ($p{\leq}0.001$) indicated that while S had higher values on day 1, thereafter the values for T were higher. The $time{\times}breed$ interaction for RML/breath indicated that values for T declined more rapidly (from 9.4 to 3.1 mgjbreath) than those for S (from 8.3 to 4.1 mgjbreath; ($p{\leq}0.01$). PCV declined during exercise ($p{\leq}0.05$) by 5.5 percentage points. The exercise imposed was stressful in that it led to increases in RR, RT and RML. S was most tolerant of exercise in that it recorded lower values of RT. The fact that the RML/breath was higher during exercies in S apparently allowed it to compensate for a lower RR. Despite higher RR and RML, T also had a higher RT, suggesting either higher muscular heat production during exercise in that breed, or higher sweating losses in S.