scholarly journals Calorespirometry reveals that goldfish prioritize aerobic metabolism over metabolic rate depression in all but near-anoxic environments

2016 ◽  
Vol 220 (4) ◽  
pp. 564-572 ◽  
Author(s):  
Matthew D. Regan ◽  
Ivan S. Gill ◽  
Jeffrey G. Richards
Keyword(s):  
Metabolic Rate ◽  
Aerobic Metabolism ◽  
Metabolic Rate Depression ◽  
Anoxic Environments

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.

scholarly journals The benefit of being still: energy savings during winter dormancy in fish come from inactivity and the cold, not from metabolic rate depression

2018 ◽  
Vol 285 (1886) ◽  
pp. 20181593 ◽  
Author(s):  
Ben Speers-Roesch ◽  
Tommy Norin ◽  
William R. Driedzic
Keyword(s):  
Metabolic Rate ◽  
Fish Species ◽  
Energy Savings ◽  
Thermal Sensitivity ◽  
Resting Metabolic Rate ◽  
Winter Dormancy ◽  
Metabolic Rate Depression ◽  
Spontaneous Movement ◽  
Anoxic Waters ◽  
Physico Chemical

Winter dormancy is used by many animals to survive the cold and food-poor high-latitude winter. Metabolic rate depression, an active downregulation of resting cellular energy turnover and thus standard (resting) metabolic rate (SMR), is a unifying strategy underlying the persistence of organisms in such energy-limited environments, including hibernating endotherms. However, controversy exists about its involvement in winter-dormant aquatic ectotherms. To address this debate, we conducted simultaneous, multi-day measurements of whole-animal oxygen consumption rate (a proxy of metabolic rate) and spontaneous movement in a model winter-dormant marine fish, the cunner ( Tautogolabrus adspersus ). Winter dormancy in cunner involved a dampened diel rhythm of metabolic rate, such that a low and stable metabolic rate persisted throughout the 24 h day. Based on the thermal sensitivity ( Q 10 ) of SMR as well as correlations of metabolic rate and movement, the reductions in metabolic rate were not attributable to metabolic rate depression, but rather to reduced activity under the cold and darkness typical of the winter refuge among substrate. Previous reports of metabolic rate depression in cunner, and possibly other fish species, during winter dormancy were probably confounded by variation in activity. Unlike hibernating endotherms, and excepting the few fish species that overwinter in anoxic waters, winter dormancy in fishes, as exemplified by cunner, need not involve metabolic rate depression. Rather, energy savings come from inactivity combined with passive physico-chemical effects of the cold on SMR, demonstrating that thermal effects on activity can greatly influence temperature–metabolism relationships, and illustrating the benefit of simply being still in energy-limited environments.

Metabolic rate depression in animals: transcriptional and translational controls

2004 ◽  
Vol 79 (1) ◽  
pp. 207-233 ◽  
Author(s):  
Kenneth B. Storey ◽  
Janet M. Storey
Keyword(s):  
Metabolic Rate ◽  
Metabolic Rate Depression

The regulation of AMPK signaling in a natural state of profound metabolic rate depression

2009 ◽  
Vol 335 (1-2) ◽  
pp. 91-105 ◽  
Author(s):  
Christopher J. Ramnanan ◽  
David C. McMullen ◽  
Amy G. Groom ◽  
Kenneth B. Storey
Keyword(s):  
Metabolic Rate ◽  
Natural State ◽  
Metabolic Rate Depression ◽  
Ampk Signaling
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