Metabolic Rate Depression and Biochemical Adaptation in Anaerobiosis, Hibernation and Estivation

1990 ◽  
Vol 65 (2) ◽  
pp. 145-174 ◽  
Author(s):  
Kenneth B. Storey ◽  
Janet M. Storey
Keyword(s):  
Metabolic Rate ◽  
Metabolic Rate Depression ◽  
Biochemical Adaptation

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.

scholarly journals The Paradox of Nocturnality in Lizards

2021 ◽  
Author(s):  
◽  
Kelly Maree Hare
Keyword(s):  
New Zealand ◽  
Metabolic Rate ◽  
Low Temperatures ◽  
Specific Activity ◽  
Glycolytic Enzyme ◽  
Activity Period ◽  
Energetic Cost ◽  
Metabolic Processes ◽  
Biochemical Adaptation ◽  
Daily Patterns

<p>Paradoxically, nocturnal lizards prefer substantially higher body temperatures than are achievable at night and are therefore active at thermally suboptimal temperatures. In this study, potential physiological mechanisms were examined that may enable nocturnal lizards to counteract the thermal handicap of activity at low temperatures: 1) daily rhythms of metabolic rate, 2) metabolic rate at low and high temperatures, 3) locomotor energetics, and 4) biochemical adaptation. A multi-species approach was used to separate evolutionary history of the species from any potential links between physiology and activity period. Four to eight species of lizards, encompassing nocturnal and diurnal lizards from the families Diplodactylidae and Scincidae, were used for all physiological measurements. Three daily patterns of metabolic rate (VO2) were apparent depending on the species: 24 h cycles, 12 h cycles, and no daily cycle. The daily patterns of VO2 and peak VO2 did not always coincide with the activity period of the species. All nocturnal lizards tested had a lower energetic cost of locomotion (Cmin) than diurnal lizards. Diurnal lizards from New Zealand also had low Cmin values when compared with nocturnal geckos and diurnal lizards from lower latitudes. Thus, a low Cmin appears to be related to activity at low temperatures rather than specifically to nocturnality. However, more data are required on lizards from high latitudes, including more New Zealand lizards, before the generality of this pattern can be confirmed. Also, based on correlations with lizards active at warmer temperatures, a low Cmin only partially offsets the thermal handicap imposed on lizards that are active at low temperatures. Nocturnal lizards were found to have lower thermal sensitivities of metabolism (lower Q10 values) than diurnal lizards, indicating that their energy-dependent activity was not as sensitive to changes in environmental temperature. The similarity of other metabolic processes among species with differing activity periods may be partly explained by the ability of nocturnal species to thermoregulate to achieve higher temperatures during the day. The amplitudes of daily VO2 cycles and mass-specific VO2 did not differ among nocturnal and diurnal New Zealand lizards at low temperatures. The specific activity of the glycolytic enzyme lactate dehydrogenase (LDH) isolated from the tail muscle of lizards was also comparable among nocturnal and diurnal lizards over a range of biologically relevant temperatures. Thus, activity of lizards at low temperatures is not enabled by lower energy requirements over a 24 h period, elevation of metabolic rates, or biochemical adaptation of LDH to specific temperatures. These results confirm that locomotion is more efficient in nocturnal lizards and diurnal lizards from New Zealand than lizards from elsewhere, but that other metabolic processes do not appear to differ among species. Additional physiological and behavioural adaptations may exist that complement the increased efficiency of locomotion, thus enabling nocturnal lizards to be active at low temperatures.</p>

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

Key Molecular Regulators of Metabolic Rate Depression in the Estivating Snail Otala Lactea

2021 ◽  
pp. 275-302
Author(s):  
Christopher J. Ramnanan ◽  
Ryan A. Bell ◽  
John-Douglas Matthew Hughes
Keyword(s):  
Metabolic Rate ◽  
Metabolic Rate Depression ◽  
Otala Lactea
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