Thermoregulation and repeatability of oxygen-consumption measurements in winter- acclimatized North American porcupines (Erethizon dorsatum)

1999 ◽  
Vol 77 (2) ◽  
pp. 194-202 ◽  
Author(s):  
François Fournier ◽  
Donald W Thomas
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
North American ◽  
Thermal Conductance ◽  
Time Intervals ◽  
Erethizon Dorsatum ◽  
Ambient Temperatures ◽  
Oxygen Gas ◽  
The Mean ◽  
Residual Values

We measured the thermoregulatory responses of 13 North American porcupines (Erethizon dorsatum) to low ambient temperatures during respirometry trials in both air and a helium-oxygen gas mixture (helox). The objective was to quantify the energy metabolism of porcupines under varying ambient temperatures. The basal metabolic rate of our winter-acclimatized porcupines was higher than expected for animals of their body size, whereas thermal conductance was lower than allometric predictions. The increase in metabolic rate that we observed at -20°C was ca. 2 X BMR, although this was not the animals' maximum thermogenic capacity. The mean increase in thermal conductance for individuals placed in a helox atmosphere over that measured in an oxygen atmosphere was 1.91 and this represented a metabolic rate of ca. 3 X BMR at -20°C. We also determined that the repeatability of oxygen-consumption measurements below thermoneutrality were highly repeatable over medium-length time intervals (mean = 11 days) for both absolute and residual values.

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.

Thermoregulation and ventilation in the tawny frogmouth, Podargus strigoides: a low-metabolic avian species

1999 ◽  
Vol 47 (2) ◽  
pp. 143 ◽  
Author(s):  
Claus Bech ◽  
Stewart C. Nicol
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Thermal Conductance ◽  
Respiratory Frequency ◽  
Mean Body Temperature ◽  
Ambient Temperatures ◽  
A Value ◽  
Ventilatory Volume

Oxygen consumption (VO2) and body temperature (Tb) were measured during daytime (corresponding to the normal resting phase) in the tawny frogmouth (Podargus strigoides, mean body mass of 341 g) at ambient temperatures (Ta) between -1ºC and 30ºC. Mean body temperature (over this range of Ta) was 37.8ºC and there was only a small (0.4ºC), and insignificant, day-night variation in Tb. Mean VO2 within thermoneutrality (25-30ºC) was 0.59 mL O2 g-1 h-1 , corresponding to a basal metabolic rate (BMR) of 3.32 W kg-1 . This value is only 61% of the predicted value for a non-passeriform bird. The minimal thermal conductance attained at Ta below thermoneutrality was 0.156 W kg-1 ºC-1, a value which is very close to the allometrically predicted value. The relatively low VO2 was paralleled by a low total ventilatory volume. This, in turn, was mainly the result of a low respiratory frequency (10.2 breaths min-1, only 52% of that expected for a similar-sized bird) whereas tidal volume (6.6 mL [BTPS]) was 107% of the expected value. Thus, our results suggest that the changing ventilatory needs during the evolution of the low VO2 in the tawny frogmouth have been met primarily by changes in respiratory frequency.

Metabolism during normoxia, hyperoxia, and recovery in newborn rats

1992 ◽  
Vol 70 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Peter B. Frappell ◽  
Andrea Dotta ◽  
Jacopo P. Mortola
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Carbon Dioxide Production ◽  
Oxygen Availability ◽  
Aerobic Metabolism ◽  
Newborn Rats ◽  
Ambient Temperatures ◽  
Positive Effects

Aerobic metabolism (oxygen consumption, [Formula: see text], and carbon dioxide production, [Formula: see text]) has been measured in newborn rats at 2 days of age during normoxia, 30 min of hyperoxia (100% O2) and an additional 30 min of recovery in normoxia at ambient temperatures of 35 °C (thermoneutrality) or 30 °C. In normoxia, at 30 °C [Formula: see text] was higher than at 35 °C. With hyperoxia, [Formula: see text] increased in all cases, but more so at 30 °C (+20%) than at 35 °C (+9%). Upon return to normoxia, metabolism readily returned to the prehyperoxic value. The results support the concept that the normoxic metabolic rate of the newborn can be limited by the availability of oxygen. At temperatures below thermoneutrality the higher metabolic needs aggravate the limitation in oxygen availability, and the positive effects of hyperoxia on [Formula: see text] are therefore more apparent.Key words: neonatal respiration, oxygen consumption, thermoregulation.

The Swimming of Nymphon Gracile (Pycnogonida): The Energetics of Swimming at Constant Depth

1977 ◽  
Vol 71 (1) ◽  
pp. 205-211
Author(s):  
ELFED MORGAN
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Tidal Cycle ◽  
Active Phase ◽  
Constant Depth ◽  
Total Carbohydrate ◽  
Drag Forces ◽  
Rate Of Oxygen Consumption ◽  
The Mean ◽  
Tide Period

1. The mechanical power required by Nymphon for swimming at constant depth has been calculated from drag forces acting on the legs. For an adult male this was found to be 3.4 W kg. Only about 60% of this is used to support the animal's weight in water. 2. The metabolic rate fluctuates spontaneously over a tidal cycle, being greatest during the ebb-tide period. The mean rate of oxygen consumption during the animals least active phase was found to be about 0.1 μlO2 mg−1 h−1. 3. The total carbohydrate and lipid immediately available for combustion have been estimated at 4.64 and 16 μg/mg wet wt respectively. These quantities should be adequate for about 42 h periodic swimming in an adult Nymphon.

Energy expenditure for thermoregulation and locomotion in emperor penguins

1976 ◽  
Vol 231 (3) ◽  
pp. 903-912 ◽  
Author(s):  
B Pinshow ◽  
MA Fedak ◽  
DR Battles ◽  
K Schmidt-Nielsen
Keyword(s):  
Metabolic Rate ◽  
Energy Requirement ◽  
Thermal Conductance ◽  
Standard Metabolic Rate ◽  
High Energy ◽  
Breeding Cycle ◽  
Emperor Penguin ◽  
Energy Reserves ◽  
Ambient Temperatures ◽  
Emperor Penguins

During the antarctic winter emperor penguins (Aptenodytes forsteri) spend up to four mo fasting while they breed at rookeries 80 km or more from the sea, huddling close together in the cold. This breeding cycle makes exceptional demands on their energy reserves, and we therefore studied their thermoregulation and locomotion. Rates of metabolism were measured in five birds (mean body mass, 23.37 kg) at ambient temperatures ranging from 25 to -47 degrees C. Between 20 and -10 degrees C the metabolic rate (standard metabolic rate (SMR)) remained neraly constant, about 42.9 W. Below -10 degrees C metabolic rate increased lineraly with decreasing ambient temperature and at -47 degrees C it was 70% above the SMR. Mean thermal conductance below -10 degrees C was 1.57 W m-2 degrees C-1. Metabolic rate during treadmill walking increased linearly with increasing speed. Our data suggest that walking 200 km (from the sea to the rookery and back) requires less than 15% of the energy reserves of a breeding male emperor penguin initially weighing 35 kg. The high energy requirement for thermoregulation (about 85%) would, in the absence of huddling, probably exceed the total energy reserves.

scholarly journals Significance of variation in basal metabolic rate in laboratory mice for translational experiments

2021 ◽  
Author(s):  
Paweł Brzęk ◽  
Andrzej Gębczyński ◽  
Piotr Selewestruk ◽  
Aneta Książek ◽  
Julita Sadowska ◽  
...  
Keyword(s):  
Physical Activity ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Activity Level ◽  
Laboratory Mice ◽  
Ambient Temperatures ◽  
Thermoneutral Zone ◽  
Significant Difference ◽  
The Mean ◽  
Spontaneous Physical Activity

AbstractThe basal metabolic rate (BMR) accounts for 60–70% of the daily energy expenditure (DEE) in sedentary humans and at least 50% of the DEE in laboratory mice in the thermoneutral zone. Surprisingly, however, the significance of the variation in the BMR is largely overlooked in translational research using such indices as physical activity level (PAL), i.e., the ratio of DEE/BMR. In particular, it is unclear whether emulation of human PAL in mouse models should be carried out within or below the thermoneutral zone. It is also unclear whether physical activity within the thermoneutral zone is limited by the capacity to dissipate heat generated by exercise and obligatory metabolic processes contributing to BMR. We measured PAL and spontaneous physical activity (SPA) in laboratory mice from two lines, divergently selected towards either high or low level of BMR, and acclimated to 30 °C (i.e., the thermoneutral zone), 23 or 4 °C. The mean PAL did not differ between both lines in the mice acclimated to 30 °C but became significantly higher in the low BMR mouse line at the lower ambient temperatures. Acclimation to 30 °C reduced the mean locomotor activity but did not affect the significant difference observed between the selected lines. We conclude that carrying out experiments within the thermoneutral zone can increase the consistency of translational studies aimed at the emulation of human energetics, without affecting the variation in physical activity correlated with BMR.

scholarly journals Oxygen Consumption During the Metamorphosis of the Parasitic Lamprey, Lampetra Fluviatilis (L.) and Its Non-Parasitic Derivative, Lampetra Planeri (Bloch)

1977 ◽  
Vol 69 (1) ◽  
pp. 187-198
Author(s):  
S. V. LEWIS ◽  
I. C. POTTER
Keyword(s):  
Circadian Rhythm ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Life Cycles ◽  
Lampetra Fluviatilis ◽  
Ventilatory Frequency ◽  
Secondary Sexual Characters ◽  
Lampetra Planeri ◽  
Slow Rise ◽  
The Mean

1. Standard oxygen consumption has been measured during the six stages of metamorphosis in both the anadromous parasitic lamprey, Lampetra fluviatilis, and in its non-parasitic derivative, Lampetra planeri. 1. Standard oxygen consumption has been measured during the six stages of metamorphosis in both the anadromous parasitic lamprey, Lampetra fluviatilis, and in its non-parasitic derivative, Lampetra planeri. 2. At 10 °C, the standard rates in larval L. planeri and L. fluviatilis of metamorphosing size were 20.3 and 29.3 μl g−1 h−1 respectively. 3. After a slow rise in oxygen consumption during the initial stages of metamorphosis, the rates reached 50.5 and 60.4 μl g−1 h−1 at stage of 6 of L. planeri and L. fluviatilis respectively. 4. Following the completion of metamorphosis in L. planeri and the development of secondary sexual characters, the mean rate in males rose to 73.3 μl g−1 h−1 compared with a decline in females to 44.1 μl g−1 h−1. 5. Although no circadian rhythm was detectable in the oxygen consumption of larvae, an elevation in the metabolic rate was present during darkness in L. fluviatilis at the end of metamorphosis. 6. Standard oxygen consumption and ventilatory frequency were influenced greatly by temperature, e.g. values for stage 6 of L. fluviatilis rose from 24.3 μl g−1 h−1 and 33.0 beats min−1 at 5 °C to 103.8 μl g−1 h−1 and 98.2 beats min−1 at 15 °C. 7. The results are discussed in the context of the radical changes taking place during metamorphosis and in terms of the differences between larvae and adult and between the life cycles of parasitic and non-parasitic lampreys.

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

Water and Energy Balance of Captive and Free-Ranging Spinifexbirds (Eremiornis Carteri) North (Aves:Sylviidae) on Barrow Island, Western Australia

1996 ◽  
Vol 44 (2) ◽  
pp. 107 ◽  
Author(s):  
SJ Ambrose ◽  
SD Bradshaw ◽  
PC Withers ◽  
DP Murphy
Keyword(s):  
Body Mass ◽  
Arid Zone ◽  
Water Flux ◽  
Thermal Conductance ◽  
Standard Metabolic Rate ◽  
Annual Rainfall ◽  
Doubly Labelled Water ◽  
Evaporative Water ◽  
Ambient Temperatures ◽  
The Mean

The mean annual rainfall of Barrow Island, located about 90 km north of Onslow off the arid Western Australian coast, is 324 mm, 74% of which falls as cyclonic rain between February and May. Spinifexbirds captured in May 1992 had a mean body mass of 12.3 +/- 0.3 g and a total body water content (TBW) of 774 +/- 1.6%. In December 1992 the mean body mass was significantly lower (11.7 +/- 0.2 g; P < 0.05), despite a TBW of 73.4 +/- 1.0%. Spinifexbirds maintained water balance in both seasons, but water flux rates were significantly higher in May (P = 0.01). Respective influx and efflux rates in May were 0.70 +/- 0.30 and 0.72 +/- 0.03 mL (g day)(-1) compared with 0.60 +/- 0.04 and 0.57 +/- 0.04 mL (g day)(-1) in December. Field metabolic rates (FMRs), measured with doubly-labelled water ((3)HH(18)0), did not differ significantly between the two periods. The mean FMR in May was 6.8 +/- 0.6 mL CO2 (g h)(-1) compared with 7.2 +/- 0.9 mL CO2 (g h)(-1) in December, similar to rates predicted by Nagy and Peterson (1988) for a similar-sized passerine. The thermoneutral zone (TNZ) of spinifexbirds, determined by metabolic laboratory trials in December, extended from 30 to 39 degrees C. The standard metabolic rate (SMR) within the TNZ was 2.9 +/- 0.1 mL O-2 (g h)(-1), which is up to 20% lower than predicted values. Body temperature was maintained at 39.1 degrees C in the TNZ, but birds became hyperthermic at ambient temperatures (T(a)s) higher than 35 degrees C, with body temperatures reaching 44 degrees C. Wet thermal conductance and evaporative water loss increased markedly at T(a)s > 35 degrees C. The data suggest that spinifexbirds have limited physiological adaptations to desert conditions compared with some other arid-zone birds.

Hibernation in the Eastern Pygmy Possum, Cercartetus-Nanus (Marsupialia, Burramyidae)

1993 ◽  
Vol 41 (1) ◽  
pp. 67 ◽  
Author(s):  
F Geiser
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Air Temperature ◽  
The Body ◽  
Daily Torpor ◽  
Rate Of Oxygen Consumption ◽  
The Mean ◽  
Cercartetus Nanus ◽  
Torpor Bouts

The pattern of torpor was examined in the eastern pygmy possum, Cercartetus nanus (21 g). Animals displayed torpor regularly in the laboratory, and the occurrence of torpor increased with decreasing air temperature (T(a)). At high T(a) (18-degrees-C) animals usually exhibited daily torpor, but torpor bouts of up to 2 days were observed occasionally. The duration of torpor bouts lengthened with a lowering of T(a) and the mean bout duration at T(a) = 5-degrees-C was 17.0 +/- 2.5 days. The minimum metabolic rate (measured as rate of oxygen consumption) of torpid individuals was 0.018 +/- 0.003 mL O2 g-1 h-1, which is less than 2% of the basal metabolic rate. The body temperature (T(b)) Of torpid animals fell to a minimum of 1.3 +/- 0.4-degrees-C. These results clearly demonstrate that Cercartetus nanus is a deep hibernator.

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