scholarly journals Effects on fetal and maternal body temperatures of exposure of pregnant ewes to heat, cold, and exercise

2002 ◽  
Vol 92 (2) ◽  
pp. 802-808 ◽  
Author(s):  
Helen P. Laburn ◽  
Alida Faurie ◽  
Kathleen Goelst ◽  
Duncan Mitchell
Keyword(s):  
Body Temperature ◽  
Relative Humidity ◽  
Treadmill Exercise ◽  
Thermal Environment ◽  
Heat Exposure ◽  
Body Temperatures ◽  
Maternal Body ◽  
Fetal Lamb ◽  
The Difference ◽  
Pregnant Ewe

We exposed Dorper-cross ewes at ∼120–135 days of gestation to a hot (40°C, 60% relative humidity) and a cold (4°C, 90% relative humidity) environment and to treadmill exercise (2.1 km/h, 5° gradient) and measured fetal lamb and ewe body temperatures using previously implanted abdominal radiotelemeters. When ewes were exposed to 2 h of heat or 30 min of exercise, body temperature rose less in the fetus than in the mother, such that the difference between fetal and maternal body temperature, on average 0.6°C before the thermal stress, fell significantly by 0.54 ± 0.06°C (SE, n = 8) during heat exposure and by 0.21 ± 0.08°C ( n = 7) during exercise. During 6 h of maternal exposure to cold, temperature fell significantly less in the fetus than in the ewe, and the difference between fetal and maternal body temperature rose to 1.16 ± 0.26°C ( n = 9). Thermoregulatory strategies used by the pregnant ewe for thermoregulation during heat or cold exposure appear to protect the fetus from changes in its thermal environment.

scholarly journals A novel mouse model of heatstroke accounting for ambient temperature and relative humidity

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Kazuyuki Miyamoto ◽  
Keisuke Suzuki ◽  
Hirokazu Ohtaki ◽  
Motoyasu Nakamura ◽  
Hiroki Yamaga ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Temperature ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
Organ Damage ◽  
Core Body ◽  
The Impact ◽  
Treatment Water

Abstract Background Heatstroke is associated with exposure to high ambient temperature (AT) and relative humidity (RH), and an increased risk of organ damage or death. Previously proposed animal models of heatstroke disregard the impact of RH. Therefore, we aimed to establish and validate an animal model of heatstroke considering RH. To validate our model, we also examined the effect of hydration and investigated gene expression of cotransporter proteins in the intestinal membranes after heat exposure. Methods Mildly dehydrated adult male C57/BL6J mice were subjected to three AT conditions (37 °C, 41 °C, or 43 °C) at RH > 99% and monitored with WetBulb globe temperature (WBGT) for 1 h. The survival rate, body weight, core body temperature, blood parameters, and histologically confirmed tissue damage were evaluated to establish a mouse heatstroke model. Then, the mice received no treatment, water, or oral rehydration solution (ORS) before and after heat exposure; subsequent organ damage was compared using our model. Thereafter, we investigated cotransporter protein gene expressions in the intestinal membranes of mice that received no treatment, water, or ORS. Results The survival rates of mice exposed to ATs of 37 °C, 41 °C, and 43 °C were 100%, 83.3%, and 0%, respectively. From this result, we excluded AT43. Mice in the AT 41 °C group appeared to be more dehydrated than those in the AT 37 °C group. WBGT in the AT 41 °C group was > 44 °C; core body temperature in this group reached 41.3 ± 0.08 °C during heat exposure and decreased to 34.0 ± 0.18 °C, returning to baseline after 8 h which showed a biphasic thermal dysregulation response. The AT 41 °C group presented with greater hepatic, renal, and musculoskeletal damage than did the other groups. The impact of ORS on recovery was greater than that of water or no treatment. The administration of ORS with heat exposure increased cotransporter gene expression in the intestines and reduced heatstroke-related damage. Conclusions We developed a novel mouse heatstroke model that considered AT and RH. We found that ORS administration improved inadequate circulation and reduced tissue injury by increasing cotransporter gene expression in the intestines.

Catecholamine elevation in iron deficiency

1979 ◽  
Vol 237 (5) ◽  
pp. R297-R300 ◽  
Author(s):  
E. Dillmann ◽  
D. G. Johnson ◽  
J. Martin ◽  
B. Mackler ◽  
C. Finch
Keyword(s):  
Body Temperature ◽  
Body Temperatures ◽  
Temperature Dependent ◽  
Urinary Catecholamines ◽  
Threefold Increase ◽  
Iron Deficient ◽  
Catecholamine Response ◽  
The Difference ◽  
And Control ◽  
Maintain Body Temperature

Iron-deficient rats have increased blood and urinary catecholamines regardless of whether anemia is or is not present. The catecholamine response in both iron-deficient and control animals is largely temperature dependent, showing little difference at the isothermic temperature of 30 degrees C but a two- to threefold increase in iron-deficient animals over controls at lower temperatures. The iron-deficient rat is unable to maintain body temperature at 4 degrees C and this is independent of anemia or of food intake. When animals are run on the treadmill for 4 h, body temperatures increase but the difference observed at 4 degrees C between iron-deficient and control animals persists. The underlying abnormality in temperature regulation and in catecholamine response disappeared after 6 days of iron therapy.

scholarly journals Thermal biology, activity, and population parameters of Cnemidophorus vacariensis (Squamata, Teiidae), a lizard endemic to southern Brazil

2011 ◽  
Vol 101 (4) ◽  
pp. 283-295 ◽  
Author(s):  
Rodrigo Caruccio ◽  
Renata Cardoso Vieira ◽  
Laura Verrastro ◽  
Denise Mello Machado
Keyword(s):  
Growth Rate ◽  
Population Structure ◽  
Body Temperature ◽  
Thermal Environment ◽  
Seasonal Activity ◽  
Southern Brazil ◽  
Body Temperatures ◽  
Thermal Biology ◽  
Environment Temperature ◽  
Average Body

We investigated the following aspects of the biology of a population of Cnemidophorus vacariensis Feltrim & Lema, 2000 during the four seasons: thermal biology, relationship with the thermal environment, daily and seasonal activity, population structure and growth rate. Cnemidophorus vacariensis is restricted to rocky outcrops of the "campos de cima da serra" grasslands on the Araucaria Plateau, southern Brazil, and is currently listed as regionally and nationally threatened with extinction. Data were collected from October 2004 through September 2007 in the state of Rio Grande do Sul. Sampling was conducted randomly from 08:00 a.m. to 6:00 p.m. The capture-mark-recapture method was employed. The lizards were captured by hand, and their cloacal temperature, sex, snout-ventral length (SVL), mass, and the temperature of their microhabitat (substrate temperature and air temperature) were recorded. Individuals were then marked by toe-clipping and released at the site of capture. Body temperatures were obtained for 175 individuals, activity data for 96 individuals, and data on population structure and growth for 59 individuals. All data were obtained monthly, at different times of the day. Cnemidophorus vacariensis average body temperature was 23.84ºC, ranging between 9.6 and 38.2ºC. Temperatures ranged between 21 and 29ºC. The correlation between external heat sources, substrate and air were positive and significant and there was a greater correlation between lizard's temperature and the temperature of the substrate (tigmothermic species). The relatively low body temperatures of individuals are associated with the climate of their environment (altitude up to 1,400 m), with large variations in temperature throughout the day and the year, and low temperatures in winter. The average body temperature observed for C. vacariensis was low when compared with that of phylogenetically related species, suggesting that the thermal biology of this species reflects adaptations to the temperate region where it lives. The monthly rates of activity of lizards were related to monthly variations in the ambient temperatures. Our data suggest that the daily and seasonal activity of C. vacariensis result from the interaction between two factors: changes in the environment temperature and the relationship between individuals and their thermal environment. The population structure of C. vacariensis varied throughout the study period, with maximum biomass in January and maximum density in February (recruitment period). The sex ratio diverged from the expected 1:1. The growth analysis showed a negative relationship between the growth rate of individuals and the SVL, revealing that young individuals grow faster than adults, a typical pattern for short-lived species. The population studied showed a seasonal and cyclical variation associated with the reproductive cycle. The life strategy of C. vacariensis seems to include adaptations to the seasonal variations in temperature, typical of its environment.

The significance of the coat in heat tolerance of cattle. II. Effect of solar radiation on body temperatures

1960 ◽  
Vol 11 (5) ◽  
pp. 871 ◽  
Author(s):  
DF Dowling
Keyword(s):  
Body Temperature ◽  
Solar Radiation ◽  
The Body ◽  
Body Temperatures ◽  
Hair Coat ◽  
Transparent Plastic ◽  
Mean Body Temperature ◽  
Clear Plastic ◽  
The Mean ◽  
The Difference

An experiment was performed to test the effect of solar radiation on the body temperatures of cattle, both clipped and with hair coat, in a clear transparent plastic covering as compared with cattle in a white reflective plastic covering. The mean body temperature of the animals in white plastic coats was 0.15°F lower than that of animals in clear plastic coats. This difference was highly significant statistically (P< 0.001). Animals in both clear and white coats had higher body temperatures than controls without plastic coats. The difference was highly significant, and was about 1.5°F in the clipped animals.

scholarly journals Field-based body temperatures reveal behavioral thermoregulation strategies of the Atlantic marsh fiddler crab Minuca pugnax

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244458
Author(s):  
Sarah Hews ◽  
Zahkeyah Allen ◽  
Adrienne Baxter ◽  
Jacquline Rich ◽  
Zahida Sheikh ◽  
...  
Keyword(s):  
Body Temperature ◽  
Surface Temperature ◽  
Fiddler Crab ◽  
Cooling Capacity ◽  
The Body ◽  
Behavioral Thermoregulation ◽  
Body Temperatures ◽  
Intertidal Crab ◽  
Trade Offs ◽  
The Difference

Behavioral thermoregulation is an important defense against the negative impacts of climate change for ectotherms. In this study we examined the use of burrows by a common intertidal crab, Minuca pugnax, to control body temperature. To understand how body temperatures respond to changes in the surface temperature and explore how efficiently crabs exploit the cooling potential of burrows to thermoregulate, we measured body, surface, and burrow temperatures during low tide on Sapelo Island, GA in March, May, August, and September of 2019. We found that an increase in 1°C in the surface temperature led to a 0.70-0.71°C increase in body temperature for females and an increase in 0.75-0.77°C in body temperature for males. Body temperatures of small females were 0.3°C warmer than large females for the same surface temperature. Female crabs used burrows more efficiently for thermoregulation compared to the males. Specifically, an increase of 1°C in the cooling capacity (the difference between the burrow temperature and the surface temperature) led to an increase of 0.42-0.50°C for females and 0.34-0.35°C for males in the thermoregulation capacity (the difference between body temperature and surface temperature). The body temperature that crabs began to use burrows to thermoregulate was estimated to be around 24°C, which is far below the critical body temperatures that could lead to death. Many crabs experience body temperatures of 24°C early in the reproductive season, several months before the hottest days of the year. Because the use of burrows involves fitness trade-offs, these results suggest that warming temperatures could begin to impact crabs far earlier in the year than expected.

scholarly journals Thermal biology of Amphisbaena munoai (Squamata: Amphisbaenidae)

2018 ◽  
Vol 35 ◽  
pp. 1-9 ◽  
Author(s):  
Nathalia Rocha Matias ◽  
Laura Verrastro
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Thermal Environment ◽  
Rio Grande ◽  
The Body ◽  
Rio Grande Do Sul ◽  
Body Temperatures ◽  
Physiological Mechanisms ◽  
Thermal Biology ◽  
The Relationship

Studies on the thermal biology of fossorial reptiles that examine the relationship between the body temperature and thermal environment are needed to determine the extent of their thermoregulation abilities. This study assessed the thermal biology of Amphisbaena munoai Klappenbach, 1969 in the rocky fields of the Rio Grande do Sul and in the laboratory. The body temperature of most individuals was between 24 and 30 °C, both in the field (n = 81) and laboratory (n = 19). More individuals were caught in winter (n = 55) and spring (n = 60) than in summer (n = 25) and fall (n = 45), and in spring, individuals showed similar nocturnal and diurnal activities. In the laboratory, we found individuals with body temperatures up to 5 °C higher than the ambient temperature (n = 4), suggesting that some physiological mechanisms participate in the thermoregulation of these animals. Amphisbaena munoai is a thigmothermic species that is capable of actively regulating its temperature by selecting microhabitats such that its various activities occur within an ideal temperature range. This study is the first to evaluate the effect of seasonality and diurnal and nocturnal variations on the thermoregulation of an amphisbaenid.

THE EFFECT OF HIGH HUMIDITY ON BODY TEMPERATURE AND OXYGEN CONSUMPTION OF NEWBORN PREMATURE INFANTS

PEDIATRICS ◽  
1961 ◽  
Vol 27 (5) ◽  
pp. 740-747
Author(s):  
Herbert C. Miller ◽  
Franklin C. Behrle ◽  
David L. Hagar ◽  
Terry R. Denison
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Relative Humidity ◽  
Premature Infants ◽  
Normal Values ◽  
The Body ◽  
High Humidity ◽  
Body Temperatures ◽  
Initial Decrease ◽  
Consistent Increase

Relative humidity between 80 and 90% increased the body temperatures of both healthy and sick premature infants, the increase being greatest in the least mature infants. No significant, consistent increase in oxygen consumption was observed to accompany the increase in body temperature produced by high relative humidity. Low relative humidity between 20 and 60% did not prevent the return of body temperature to normal values after the initial decrease immediately following birth. The return to normal was slower in the less mature infants. Low relative humidity was not incompatible with the survival of very small premature infants maintained in an ambient temperature betwen 88 and 90°F (31.1 to 32.2°C).

Circadian variations in the sweating mechanism

1975 ◽  
Vol 39 (2) ◽  
pp. 226-230 ◽  
Author(s):  
J. Timbal ◽  
J. Colin ◽  
C. Boutelier
Keyword(s):  
Body Temperature ◽  
Human Subjects ◽  
Heat Exposure ◽  
The Body ◽  
Circadian Variations ◽  
Mean Body Temperature ◽  
Two Temperatures ◽  
The Difference ◽  
Gains And Losses ◽  
Skin Temperatures

Sweat rates and body temperatures of human subjects were measured at 0200, 1000, and 1800 h during a heat exposure of 90 min. The latent period of sweating was not significantly altered in the evening but significantly shortened during the night. Mean body temperature corresponding to the onset of sweating was nearer to the basal body temperature during the night, while during the day the difference between these two temperatures became larger. This phenomenon seems related to the circadian cycle of vasomotor adjustment, since during the night body conductance was higher than during the day and corresponded to a state of a vasodilatation similar to that observed at the onset of sweating. During the day, this situation was reversed. During steady state, the following changes were observed: sweating rate, night less than morning less than evening; skin temperatures, night less than morning less than evening; and rectal temperature increase, morning less than evening less than night. It is hypothesized that these changes are due to either different metabolic rates or an imbalance between heat gains and losses which preserve the circadian rhythm of the body temperature, even under thermal loads.

Fetal and maternal body temperatures measured by radiotelemetry in near-term sheep during thermal stress

1992 ◽  
Vol 72 (3) ◽  
pp. 894-900 ◽  
Author(s):  
H. P. Laburn ◽  
D. Mitchell ◽  
K. Goelst
Keyword(s):  
Thermal Stress ◽  
Body Temperature ◽  
Temperature Gradient ◽  
Thermal Injury ◽  
Exposure Period ◽  
Body Temperatures ◽  
Initial Exposure ◽  
Mild Heat ◽  
Near Term ◽  
Pregnant Ewe

Using implanted radiotelemeters, we have measured amniotic temperature and fetal lamb and pregnant ewe body temperatures continuously over the last 34 days of gestation and during conditions of thermal stress. Body temperature of the fetus was approximately 0.6 degrees C higher than that of the mother, and the fetomaternal temperature difference remained constant over the last 25 days of gestation, until the immediate prepartum period, when it rose. During exposure to mild heat stress (35 degrees C dry-bulb temperature, 24 degrees C wet-bulb temperature), ewe and fetal body temperatures rose, but fetal temperature rose at a slower rate. Thus the fetomaternal temperature gradient fell significantly in the initial exposure period. In an environment of 4 degrees C, body temperature of the pregnant ewes fell, but the fetomaternal gradient did not change significantly. During maternal fever, heat loss from the fetus was compromised; body temperature of the fetus rose more than that of the mother, and the fetomaternal temperature gradient rose significantly. We suggest that mild heat or cold exposure in pregnant animals constitutes little risk of fetal thermal stress. During maternal fever, however, the fetus may be at risk of thermal injury.

scholarly journals Field body temperature and thermal preference of the big-headed turtle Platysternon megacephalum

2013 ◽  
Vol 59 (5) ◽  
pp. 626-632 ◽  
Author(s):  
Jianwei Shen ◽  
Fanwei Meng ◽  
Yongpu Zhang ◽  
Weiguo Du
Keyword(s):  
Food Intake ◽  
Body Temperature ◽  
Thermal Environment ◽  
The Body ◽  
Freshwater Turtle ◽  
Diel Variation ◽  
Thermal Preference ◽  
Body Temperatures ◽  
Low Field ◽  
Preferred Body Temperature

Abstract The big-headed turtle Platysternon megacephalum is a stream-dwelling species whose ecology is poorly known. We carried out field and laboratory investigations to determine field body temperatures and thermal preference of this species. In the field, the body temperatures of the turtles conformed to the water temperature, with little diel variation in either summer or autumn. Over the diel cycle, the mean body temperatures ranged from 20.8°C to 22.2°C in summer and from 19.3°C to 21.2°C in autumn; the highest body temperatures ranged from 22.1°C to 25.0°C in summer and from 20.6°C to 23.8°C in autumn. In the laboratory, the preferred body temperature (Tp) was 25.3°C. Food intake was maximized at 24.0°C, whereas locomotor performance peaked at 30.0°C. Consequently, Tp was closer to the thermal optimum for food intake than for locomotion. Therefore, this freshwater turtle has relative low field body temperatures corresponding to its thermal environment. In addition, the turtle prefers low temperatures and has a low optimal temperature for food intake.

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