Diurnal body temperature variations and hibernation in the birchmouse, Sicista betulina

1959 ◽  
Vol 196 (6) ◽  
pp. 1200-1204 ◽  
Author(s):  
Kjell Johansen ◽  
John Krog
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Respiratory Rate ◽  
Maximal Activity ◽  
Temperature Cycle ◽  
Body Temperatures ◽  
Temperature Variations ◽  
Ambient Temperatures ◽  
The Awakening ◽  
Compensatory Increase

Body temperatures, oxygen consumption and electrocardiograms were recorded in the birchmouse. The diurnal body temperature cycle ranged from 5° to 18°C during a regular 24-hour sequence. The highest body temperatures (37–38°C) are present around midnight, coinciding with the time of maximal activity. Body temperatures and oxygen consumption were studied at various ambient temperatures. With decreasing temperature the oxygen consumption commonly followed two successive patterns: first, a period of compensatory increase after which body temperature and oxygen consumption decreased; the compensation lasted from 5 minutes to 4 hours. At low ambient temperatures the animals went into a state of dormancy similar to seasonal hibernation in other mammals. The reduction in heart and respiratory rate as well as in oxygen consumption and body temperature confirmed those values reported earlier. Arousal from hibernation in the birchmouse is unique in the great speed of reaction with which the awakening takes place. Body temperature may increase as much as 1°C/min. and, within a period of 30 minutes, the oxygen consumption may increase 25 times.

scholarly journals Body Temperatures in Some Australian Mammals II.Peramelidae

1962 ◽  
Vol 15 (2) ◽  
pp. 386 ◽  
Author(s):  
PR Morrison
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Active Phase ◽  
Temperature Measurements ◽  
Temperature Cycle ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Diurnal Temperature

Body temperature measurements on the short-nosed bandicoot (Thylacis obeaulus) have shown a nocturnal cycle with a range of 1� 2�C and a short active phase at 2200-0400 hr. The bilby or rabbit bandicoot (Macrotis lagoti8) had a sharply defined temperature cycle, with a range of almost 3�C after several months of captivity, during which the day-time resting temperature was progressively lowered from 36� 4 to 34� 2�C. Forced activity raised the diurnal temperature substantially but not to the nocturnal level. Forced activity did not raise the nocturnal level which was similar in the two species (37' O�C). Both species could regulate effectively at an ambient temperature of 5�C, but only Thylaci8 showed regulation at ambient temperatures of between 30 and 40�C.

Body temperature regulation and oxygen consumption in young chicks fed thyroid hormone

1991 ◽  
Vol 69 (7) ◽  
pp. 1842-1847 ◽  
Author(s):  
Gregory K. Snyder ◽  
Joseph R. Coelho ◽  
Dalan R. Jensen
Keyword(s):  
Oxygen Consumption ◽  
Thyroid Hormone ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Cold Exposure ◽  
Elevated Serum ◽  
Body Temperatures ◽  
Serum Thyroid Hormone ◽  
Regulate Body Temperature ◽  
Young Chicks

In chicks the ability to regulate body temperature to adult levels develops during the first 2 weeks of life. We examined whether the ability of young chicks to regulate body temperature is increased by elevated levels of the thyroid hormone 3,3′5-triiodothyronine. By 13 days following hatch, body temperatures of chicks were not significantly different from those expected for adult birds. Furthermore, at an ambient temperature of 10 °C, 13-day-old control chicks were able to maintain body temperature, and elevated serum thyroid hormone levels did not increase rates of oxygen consumption or body temperature above control values. Six-day-old chicks had body temperatures that were significantly lower than those of the 13-day-old chicks and were not able to regulate body temperature when exposed to an ambient temperature of 10 °C. On the other hand, 6-day-old chicks with elevated serum thyroid hormone had significantly higher rates of oxygen consumption than 6-day-old control chicks, and were able to maintain constant body temperatures during cold exposure. The increased oxygen consumption rates and improved ability to regulate body temperature during cold exposure were correlated with increased citrate synthase activity in skeletal muscle. Our results support the argument that thyroid hormones play an important role in the development of thermoregulatory ability in neonate birds by stimulating enzyme activities associated with aerobic metabolism.

The metabolic rate and thermal conductance of the eastern barred bandicoot (Perameles gunnii) at different ambient temperatures

2003 ◽  
Vol 51 (6) ◽  
pp. 603 ◽  
Author(s):  
M. P. Ikonomopoulou ◽  
R. W. Rose
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Thermal Conductance ◽  
The Body ◽  
High Metabolic Rate ◽  
Ambient Temperatures ◽  
Reduced Body ◽  
Thermoneutral Zone ◽  
Reproductive Females

We investigated the metabolic rate, thermoneutral zone and thermal conductance of the eastern barred bandicoot in Tasmania. Five adult eastern barred bandicoots (two males, three non-reproductive females) were tested at temperatures of 3, 10, 15, 20, 25, 30, 35 and 40°C. The thermoneutral zone was calculated from oxygen consumption and body temperature, measured during the daytime: their normal resting phase. It was found that the thermoneutral zone lies between 25°C and 30°C, with a minimum metabolic rate of 0.51 mL g–1 h–1 and body temperature of 35.8°C. At cooler ambient temperatures (3–20°C) the body temperature decreased to approximately 34.0°C while the metabolic rate increased from 0.7 to 1.3 mL g–1�h–1. At high temperatures (35°C and 40°C) both body temperature (36.9–38.7°C) and metabolic rate (1.0–1.5 mL g–1 h–1) rose. Thermal conductance was low below an ambient temperature of 30°C but increased significantly at higher temperatures. The low thermal conductance (due, in part, to good insulation, a reduced body temperature at lower ambient temperatures, combined with a relatively high metabolic rate) suggests that this species is well adapted to cooler environments but it could not thermoregulate easily at temperatures above 30°C.

Continuous radio telemetry of hypothalamic temperatures from unrestrained animals

1965 ◽  
Vol 20 (2) ◽  
pp. 321-325 ◽  
Author(s):  
Robert O. Rawson ◽  
Jan A. J. Stolwijk ◽  
Hans Graichen ◽  
Robert Abrams
Keyword(s):  
Motor Activity ◽  
Radio Telemetry ◽  
Temperature Cycle ◽  
Body Temperatures ◽  
Night Temperature ◽  
Hypothalamic Temperature ◽  
Temperature Variations ◽  
Free Running ◽  
Hot Environments

A system of radio telemetry has been designed which continuously records body temperatures of unrestrained animals with a resolution of 0.05 C over transmission distances of 100ˑ1,000 ft, permitting observations on free-running animals for indefinite periods of time. Continuous 24-hr recordings were made of hypothalamic temperatures telemetered from cold-acclimatized and unacclimatized dogs living in cold, neutral, and hot environments. During night hours, dogs usually exhibited a decrease in hypothalamic temperature of 0.5ˑ.0 C below daylight levels. Superimposed on the day-night temperature cycle are marked fluctuations of 0.1ˑ0.5 C at a rate of 0.1 C/min. These variations are associated with the level of motor activity, arousal, and with periods of dozing. Shivering in the cold is exhibited even though hypothalamic temperature may be elevated above a level at which no shivering occurs in a neutral environment. spontaneous hypothalamic temperature variations; cold-acclimatized dogs; day-night temperature cycle Submitted on June 3, 1964

Standard metabolic rate and preferred body temperatures in some Australian pythons

1998 ◽  
Vol 46 (4) ◽  
pp. 317 ◽  
Author(s):  
Gavin S. Bedford ◽  
Keith A. Christian
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Thermal Sensitivity ◽  
Standard Metabolic Rate ◽  
Allometric Equations ◽  
Metabolic Rates ◽  
Body Temperatures ◽  
Daily Cycle ◽  
Preferred Body Temperature

Pythons have standard metabolic rates and preferred body temperatures that are lower than those of most other reptiles. This study investigated metabolic rates and preferred body temperatures of seven taxa of Australian pythons. We found that Australian pythons have particularly low metabolic rates when compared with other boid snakes, and that the metabolic rates of the pythons did not change either seasonally or on a daily cycle. Preferred body temperatures do vary seasonally in some species but not in others. Across all species and seasons, the preferred body temperature range was only 4.9˚C. The thermal sensitivity (Q10) of oxygen consumption by pythons conformed to the established range of between 2 and 3. Allometric equations for the pooled python data at each of the experimental temperatures gave an equation exponent of 0.72–0.76, which is similar to previously reported values. By having low preferred body temperatures and low metabolic rates, pythons appear to be able to conserve energy while still maintaining a vigilant ‘sit and wait’ predatory existence. These physiological attributes would allow pythons to maximise the time they can spend ‘sitting and waiting’ in the pursuit of prey.

Inhibition of shivering in hypothermic seals during diving

2005 ◽  
Vol 289 (2) ◽  
pp. R326-R331 ◽  
Author(s):  
Petter H. Kvadsheim ◽  
Lars P. Folkow ◽  
Arnoldus Schytte Blix
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Cold Water ◽  
Brain Temperature ◽  
Muscular Activity ◽  
Emg Activity ◽  
Ambient Temperatures ◽  
Metabolic Heat ◽  
Cystophora Cristata ◽  
Increase Oxygen Consumption

The mammalian response to hypothermia is increased metabolic heat production, usually by way of muscular activity, such as shivering. Seals, however, have been reported to respond to diving with hypothermia, which in other mammals under other circumstances would have elicited vigorous shivering. In the diving situation, shivering could be counterproductive, because it obviously would increase oxygen consumption and therefore reduce diving capacity. We have measured the electromyographic (EMG) activity of three different muscles and the rectal and brain temperature of hooded seals ( Cystophora cristata) while they were exposed to low ambient temperatures in a climatic chamber and while they performed a series of experimental dives in cold water. In air, the seals had a normal mammalian shivering response to cold. Muscles were recruited in a sequential manner until body temperature stopped dropping. Shivering was initiated when rectal temperature fell below 35.3 ± 0.6°C ( n = 6). In the hypothermic diving seal, however, the EMG activity in all of the muscles that had been shivering vigorously before submergence was much reduced, or stopped altogether, whereas it increased again upon emergence but was again reduced if diving was repeated. We conclude that shivering is inhibited during diving to allow a decrease in body temperature whereby oxygen consumption is decreased and diving capacity is extended.

Temperature regulation and cold acclimation in the golden hamster

1965 ◽  
Vol 20 (3) ◽  
pp. 405-410 ◽  
Author(s):  
Hermann Pohl
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Cold Acclimation ◽  
Heat Production ◽  
Golden Hamster ◽  
Thermal Conductance ◽  
Muscular Activity ◽  
The Body ◽  
Ambient Temperatures

Characteristics of cold acclimation in the golden hamster, Mesocricetus auratus, were 1) higher metabolic rate at -30 C, 2) less shivering when related to ambient temperature or oxygen consumption, and 3) higher differences in body temperature between cardiac area and thoracic subcutaneous tissues at all ambient temperatures tested, indicating changes in tissue insulation. Cold-acclimated hamsters also showed a rise in temperature of the cardiac area when ambient temperature was below 15 C. Changes in heat distribution in cold-acclimated hamsters suggest higher blood flow and heat production in the thoracic part of the body in the cold. The thermal conductance through the thoracic and lumbar muscle areas, however, did not change notably with lowering ambient temperature. Marked differences in thermoregulatory response to cold after cold acclimation were found between two species, the golden hamster and the thirteen-lined ground squirrel, showing greater ability to regulate body temperature in the cold in hamsters. hibernator; oxygen consumption— heat production; body temperature — heat conductance; muscular activity — shivering; thermoregulation Submitted on July 6, 1964

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).

Thermoregulatory responses of dystrophic hamsters to changes in ambient temperatures

1985 ◽  
Vol 63 (9) ◽  
pp. 1145-1150 ◽  
Author(s):  
M. Desautels ◽  
R. A. Dulos ◽  
J. A. Thornhill
Keyword(s):  
Carbon Dioxide ◽  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Activity ◽  
Carbon Dioxide Production ◽  
Ambient Temperatures ◽  
Brown Adipose ◽  
Lower Temperature ◽  
Do So

The ability of dystrophic hamsters to maintain their body temperature despite abnormal muscle and brown adipose tissue, two organs involved in thermoregulation, was evaluated. Dystrophic hamsters (CHF 146) between the ages of 30 and 160 days kept at 21 °C had core (rectal) temperatures (TR) that were 0.5–1.5 °C lower than Golden Syrian controls. The reduced core temperatures of dystrophic hamsters were unlikely the result of an incapacity to generate heat since the dystrophic hamsters were able to maintain their TRs during 3 h of acute cold stress (4 °C) and to adapt to prolonged cold exposure. However, TRs of cold-acclimated dystrophic hamsters were still 1 °C below TRs of cold-acclimated control animals. By contrast, increasing the ambient temperature raised TRs of both normal and dystrophic hamsters. When kept at 32 °C overnight, the TRs of dystrophic hamsters remained significantly below those of control animals. When heat-exposed dystrophic hamsters were returned to 21 °C, their TRs returned to values significantly lower than those of control hamsters. Thus, dystrophic hamsters showed a capacity to thermoregulate, like control hamsters, but appeared to do so at a lower temperature. The reduced core temperatures of dystrophic hamsters kept at 21 °C cannot be explained by a reduction in metabolic activity since newborns and 30- and 140-day-old dystrophic hamsters had rates of oxygen consumption [Formula: see text] and carbon dioxide production [Formula: see text] that were similar to those of controls. These results suggest that the thermoregulatory set point may be altered in dystrophic hamsters.

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