Oxygen consumption and body temperature during sleep in cold environments

1959 ◽  
Vol 14 (5) ◽  
pp. 765-767 ◽  
Author(s):  
M. B. Kreider ◽  
P. F. Iampietro
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Skin Temperature ◽  
Ambient Temperatures ◽  
Cold Environments ◽  
Body Cooling ◽  
Skin Temperatures ◽  
Body Heat

Six young soldiers slept at the following ambient temperatures: 25.5° to 26℃ (78–80℉), 15° to 18.5°C (60°–65℉) and -32° to -34.5℃ (-25°--30℉). Rectal (Tr) and skin temperatures were recorded and mean weighted skin temperature (Ts) was calculated at -hour intervals every night; oxygen consumption (Vo2) was measured at 6-minute intervals on occasional nights. During sleep at a ‘comfortable’ temperature (25.5℃) Tr, Ts and Vo2 decreased below the resting levels measured just before retiring. During sleep in cold environments, Tr and Ts dropped to still lower levels with the lowest values recorded at an early hour of the night. Vo2 during sleep in the cold did not differ from values recorded during sleep at 25.5℃. Lowest values measured during sleep in the coldest environment were 35.5°C, 30.5℃ and 78 Cal/m2 for Tr, Ts and body heat debt, respectively. These values may represent the limits of body cooling compatible with substantially continuous sleep in the cold. Submitted on February 19, 1959

Respiratory responses to noxious and nonnoxious heating of skin in cats

1984 ◽  
Vol 57 (6) ◽  
pp. 1738-1741 ◽  
Author(s):  
T. G. Waldrop ◽  
D. E. Millhorn ◽  
F. L. Eldridge ◽  
L. E. Klingler
Keyword(s):  
Body Temperature ◽  
Skin Temperature ◽  
Core Body Temperature ◽  
Warm Receptors ◽  
End Tidal ◽  
Core Body ◽  
Decerebrate Cats ◽  
Skin Temperatures ◽  
Respiratory Responses ◽  
Stimulation Of

Respiratory responses to increased skin temperatures were recorded in anesthetized cerebrate and in unanesthetized decerebrate cats. All were vagotomized, glomectomized, and paralyzed. Core body temperature and end-tidal Pco2 were kept constant with servoncontrollers. Stimulation of cutaneous nociceptors by heating the skin to 46 degrees C caused respiration to increase in both cerebrate and decerebrate cats. An even larger facilitation of respiration occurred when the skin temperature was elevated to 51 degrees C. However, respiration did not increase in either group of cats when the skin was heated to 41 degrees C to activate cutaneous warm receptors. The phenomenon of sensitization of nociceptors was observed. Spinal transection prevented all the respiratory responses to cutaneous heating. We conclude that noxious, but not nonnoxious, increases in skin temperature cause increases in respiratory output.

Dual core and shell temperature regulation during sea acclimatization in Gentoo penguins (Pygoscelis papua)

1994 ◽  
Vol 266 (4) ◽  
pp. R1319-R1326 ◽  
Author(s):  
E. Dumonteil ◽  
H. Barre ◽  
J. L. Rouanet ◽  
M. Diarra ◽  
J. Bouvier
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Thermal Insulation ◽  
Cold Water ◽  
Threshold Temperature ◽  
Ambient Temperatures ◽  
Adaptation To Cold ◽  
Marine Life ◽  
Shell Temperature ◽  
Skin Temperatures

Penguins are able to maintain a high and constant body temperature despite a thermally constraining environment. Evidence for progressive adaptation to cold and marine life was sought by comparing body and peripheral skin temperatures, metabolic rate, and thermal insulation in juvenile and adult Gentoo penguins exposed to various ambient temperatures in air (from -30 to +30 degrees C) and water (3-35 degrees C). Juvenile penguins in air showed metabolic and insulative capacities comparable with those displayed by adults. Both had a lower critical temperature (LCT) close to 0 degree C. In both adults and juveniles, the intercept of the metabolic curve with the abscissa at zero metabolic rate was far below body temperature. This was accompanied by a decrease in thermal insulation below LCT, allowing the preservation of a threshold temperature in the shell. However, this shell temperature maintenance was progressively abandoned in immersed penguins as adaptation to marine life developed, probably because of its prohibitive energy cost in water. Thus adaptation to cold air and to cold water does not rely on the same kind of reactions. Both of these strategies fail to follow the classical sequence linking metabolic and insulative reactions in the cold.

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.

Extremity skin temperature in British and Zebu cross cattle

1967 ◽  
Vol 69 (1) ◽  
pp. 1-7 ◽  
Author(s):  
K. G. Johnson ◽  
M. E. D. Webster
Keyword(s):  
Skin Temperature ◽  
Lower Leg ◽  
Zebu Cattle ◽  
Temperature Changes ◽  
Ambient Temperatures ◽  
Thermal Environments ◽  
Air Temperatures ◽  
Environmental Temperatures ◽  
Skin Temperatures ◽  
Trunk Skin

1. Extremity skin temperature changes in British and Zebu cross cattle examined in moderate thermal environments followed a thermoregulatory pattern similar to that describedby Whittow (1962). At low environmental temperatures, ear and lower leg skin temperatures were usually only slightly above air temperature. At a variable time after air temperatures began to rise or the animals were fed, extremity skin temperatures increased suddenly to near trunk skin temperature.2. In eight of the ten pairs of animals studied in rising ambient temperatures and during feeding after fasting for 36–72 hr, increases in ear temperature were measured in the British animal before similar changes occurred in its Zebu counterpart. Changes in lower leg skin temperature followed a similar pattern.Trunk skin temperatures and respiratory frequencies were significant higher in British cross animals than in Zebu cross animals of similar thermal history. The mean rectal temperature of both British and Zebu cattle was 38·5 °C.

Observations on the effect of salicylate in fever and the regulation of body temperature against cold

1976 ◽  
Vol 54 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Q. J. Pittman ◽  
W. L. Veale ◽  
K. E. Cooper
Keyword(s):  
Body Temperature ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Heat Production ◽  
Intravenous Infusion ◽  
Sodium Salicylate ◽  
Single Injection ◽  
Continuous Intravenous Infusion ◽  
Skin Temperatures

Prostaglandins appear to be mediators, within the hypothalamus, of heat production and conservation during fever. We have investigated a possible role of prostaglandins in the nonfebrile rabbit during thermoregulation in the cold. Shorn rabbits were placed in an environment of 20 °C, and rectal and ear skin temperatures, shivering and respiratory rates were measured. A continuous intravenous infusion of leucocyte pyrogen was given to establish a constant fever of approximately 1 °C, and after observation of a stable febrile temperature for 90 min, a single injection of 300 mg of sodium salicylate, followed by a 1.5 mg/min infusion was then given. After the salicylate infusion was begun, rectal temperature began to fall, and reached nonfebrile levels within 90 min. Shivering activity ceased, respiratory rates increased, and in two animals, ear skin temperature increased. When these same rabbits were placed in an environment of 10 °C, at a time they were not febrile, and an identical amount of salicylate was given, rectal and ear skin temperatures, shivering and respiratory rates did not change. These results indicate that prostaglandins do not appear to be involved in heat production and conservation in the nonfebrile rabbit.

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.

A mechanism by which helium increases metabolism in small mammals

1960 ◽  
Vol 199 (2) ◽  
pp. 243-245 ◽  
Author(s):  
H. A. Leon ◽  
S. F. Cook
Keyword(s):  
Thermal Conductivity ◽  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Heat Loss ◽  
Small Mammals ◽  
Thermal Gradient ◽  
Oxygen Mixture ◽  
Ambient Temperatures ◽  
Long Evans

The oxygen consumption of male Long-Evans rats was determined at three different ambient temperatures in air and in an equivalent helium-oxygen mixture. It was found that when the ambient temperature is near the skin temperature of the rat, the effect of helium is insignificant. If the ambient temperature is lowered, helium induces an increased metabolism over air at the same temperature. Since helium has a thermal conductivity about six times greater than nitrogen, it is concluded that the accelerated metabolism is in response to the greater heat loss in the presence of helium and the magnitude of this response is proportional to the thermal gradient between the animal and the environment.

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

Thermoregulation in Exercising White Rats

1973 ◽  
Vol 51 (11) ◽  
pp. 814-824 ◽  
Author(s):  
K. Myhre ◽  
B. Hellstrøm
Keyword(s):  
Thermal Stress ◽  
Skin Temperature ◽  
Albino Rats ◽  
Cold Environment ◽  
Exercise Time ◽  
Ambient Temperatures ◽  
Warm Environment ◽  
White Rats ◽  
Skin Temperatures ◽  
Trunk Skin

Colonic temperatures (TC), heart rates (HR), back skin and tail skin temperatures (TST) were measured in six warm acclimated (+24 °C) male albino rats running on a treadmill at three different work loads (HR ranging from 400 beats/min to 500 beats/min). Ambient temperatures (TA) ranged from about +8 °C to about +30 °C. TC increased immediately upon onset of work. Exercising in a cold environment ultimately made the rats hypothermic and in a warm environment hyperthermic. Within the limits set by the external thermal stress the rats controlled TC independently of the work intensity.High trunk skin temperatures were recorded in all experiments. Exercise in cold and cool environments produced tail skin vasoconstriction. In the 21 °C environment half of the rats produced tail skin vasodilation. In the 28 °C environment most experiments produced this effect. Cessation of work was accompanied by prompt vasoconstriction. The results indicated that exercise time before tail vasodilation was affected by exercise as well as by the tail skin temperature prior to vasodilation.

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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