When Nonshivering Thermogenesis Equals Maximum Metabolic Rate: Thermal Acclimation and Phenotypic Plasticity of FossorialSpalacopus cyanus(Rodentia)

2001 ◽  
Vol 74 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Roberto F. Nespolo ◽  
Leonardo D. Bacigalupe ◽  
Enrico L. Rezende ◽  
Francisco Bozinovic
Keyword(s):  
Phenotypic Plasticity ◽  
Metabolic Rate ◽  
Thermal Acclimation ◽  
Nonshivering Thermogenesis ◽  
Maximum Metabolic Rate

scholarly journals Thermal Acclimation to the Highest Natural Ambient Temperature Compromises Physiological Performance in Tadpoles of a Stream-Breeding Savanna Tree Frog

2021 ◽  
Vol 12 ◽  
Author(s):  
Leonardo S. Longhini ◽  
Lucas A. Zena ◽  
Elias T. Polymeropoulos ◽  
Aline C. G. Rocha ◽  
Gabriela da Silva Leandro ◽  
...  
Keyword(s):  
Heart Rate ◽  
Metabolic Rate ◽  
Thermal Acclimation ◽  
Future Climate Change ◽  
Tree Frog ◽  
Critical Thermal Maximum ◽  
Physiological Performance ◽  
Thermal Maximum ◽  
Before And After ◽  
Maximum Metabolic Rate

Amphibians may be more vulnerable to climate-driven habitat modification because of their complex life cycle dependence on land and water. Considering the current rate of global warming, it is critical to identify the vulnerability of a species by assessing its potential to acclimate to warming temperatures. In many species, thermal acclimation provides a reversible physiological adjustment in response to temperature changes, conferring resilience in a changing climate. Here, we investigate the effects of temperature acclimation on the physiological performance of tadpoles of a stream-breeding savanna tree frog (Bokermannohyla ibitiguara) in relation to the thermal conditions naturally experienced in their microhabitat (range: 18.8–24.6°C). We quantified performance measures such as routine and maximum metabolic rate at different test (15, 20, 25, 30, and 34°C) and acclimation temperatures (18 and 25°C). We also measured heart rate before and after autonomic blockade with atropine and sotalol at the respective acclimation temperatures. Further, we determined the critical thermal maximum and warming tolerance (critical thermal maximum minus maximum microhabitat temperature), which were not affected by acclimation. Mass-specific routine and mass-specific maximum metabolic rate, as well as heart rate, increased with increasing test temperatures; however, acclimation elevated mass-specific routine metabolic rate while not affecting mass-specific maximum metabolic rate. Heart rate before and after the pharmacological blockade was also unaffected by acclimation. Aerobic scope in animals acclimated to 25°C was substantially reduced, suggesting that physiological performance at the highest temperatures experienced in their natural habitat is compromised. In conclusion, the data suggest that the tadpoles of B. ibitiguara, living in a thermally stable environment, have a limited capacity to physiologically adjust to the highest temperatures found in their micro-habitat, making the species more vulnerable to future climate change.

scholarly journals Analytical methods matter too: Establishing a framework for estimating maximum metabolic rate for fishes

2021 ◽  
Author(s):  
Tanya S. Prinzing ◽  
Yangfan Zhang ◽  
Nicholas C. Wegner ◽  
Nicholas K. Dulvy
Keyword(s):  
Metabolic Rate ◽  
Analytical Methods ◽  
Maximum Metabolic Rate

scholarly journals Changes in body temperature influence the scaling of and aerobic scope in mammals

2006 ◽  
Vol 3 (1) ◽  
pp. 100-103 ◽  
Author(s):  
James F Gillooly ◽  
Andrew P Allen
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Size Dependence ◽  
Maximal Activity ◽  
Scaling Exponent ◽  
Temperature Influence ◽  
Aerobic Scope ◽  
Metabolic Scope ◽  
Single Power ◽  
Maximum Metabolic Rate

Debate on the mechanism(s) responsible for the scaling of metabolic rate with body size in mammals has focused on why the maximum metabolic rate ( ) appears to scale more steeply with body size than the basal metabolic rate (BMR). Consequently, metabolic scope, defined as /BMR, systematically increases with body size. These observations have led some to suggest that and BMR are controlled by fundamentally different processes, and to discount the generality of models that predict a single power-law scaling exponent for the size dependence of the metabolic rate. We present a model that predicts a steeper size dependence for than BMR based on the observation that changes in muscle temperature from rest to maximal activity are greater in larger mammals. Empirical data support the model's prediction. This model thus provides a potential theoretical and mechanistic link between BMR and .

scholarly journals Do method and species lifestyle affect measures of maximum metabolic rate in fishes?

2016 ◽  
Vol 90 (3) ◽  
pp. 1037-1046 ◽  
Author(s):  
S. S. Killen ◽  
T. Norin ◽  
L. G. Halsey
Keyword(s):  
Metabolic Rate ◽  
Maximum Metabolic Rate

Cold acclimation-recruited nonshivering thermogenesis: the Syrian hamster is not an exception

1995 ◽  
Vol 269 (4) ◽  
pp. R767-R774 ◽  
Author(s):  
A. Dicker ◽  
B. Cannon ◽  
J. Nedergaard
Keyword(s):  
Metabolic Rate ◽  
Cold Acclimation ◽  
Resting Metabolic Rate ◽  
High Rate ◽  
In Vivo Studies ◽  
Nonshivering Thermogenesis ◽  
Brown Adipose ◽  
Thermogenic Response

Biochemical evidence from in vitro studies of brown adipose tissue in Syrian hamsters indicates a significant degree of recruitment of the tissue as an effect of cold acclimation. However, earlier in vivo studies indicate a lack of recruitment of nonshivering thermogenesis in the intact animal as a result of cold acclimation. Because of this apparent discrepancy, the occurrence of cold acclimation-recruited nonshivering thermogenesis in hamsters was investigated. Hamsters were cold acclimated to 6 degrees C or remained at 24 degrees C (controls), and their thermogenic response was investigated in an open-circuit system at 24 degrees C. Cold acclimation resulted in a small increase in resting metabolic rate and a major increase in the thermogenic response to norepinephrine (61% increase over resting metabolic rate in controls and 156% increase in cold-acclimated animals). The absolute beta 3-specific adrenergic agonist CGP-12177 also induced a high rate of nonshivering thermogenesis, which was similarly recruited. It was concluded that, concerning the relative effect of recruitment on the capacity for nonshivering thermogenesis, the intact hamsters responded as would be predicted from in vitro experiments. Thus the hamster does not seem to constitute an exception to the general patterns described for other rodents concerning recruitment of nonshivering thermogenesis due to cold acclimation.

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