Metabolic rate does not scale with body mass in cultured mammalian cells

2007 ◽  
Vol 292 (6) ◽  
pp. R2115-R2121 ◽  
Author(s):  
Melanie F. Brown ◽  
Tyson P. Gratton ◽  
Jeffrey. A. Stuart
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Oxygen Delivery ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Mammalian Species ◽  
Cellular Respiration ◽  
Metabolic Rates ◽  
Respiration Rates ◽  
Species Specific

The allometric scaling of metabolic rate with organism body mass can be partially accounted for by differences in cellular metabolic rates. For example, hepatocytes isolated from horses consume almost 10-fold less oxygen per unit time as mouse hepatocytes [Porter and Brand, Am J Physiol Regul Integr Comp Physiol 269: R226–R228, 1995]. This could reflect a genetically programmed, species-specific, intrinsic metabolic rate set point, or simply the adaptation of individual cells to their particular in situ environment (i.e., within the organism). We studied cultured cell lines derived from 10 mammalian species with donor body masses ranging from 5 to 600,000 g to determine whether cells propagated in an identical environment (media) exhibited metabolic rate scaling. Neither metabolic rate nor the maximal activities of key enzymes of oxidative or anaerobic metabolism scaled significantly with donor body mass in cultured cells, indicating the absence of intrinsic, species-specific, cellular metabolic rate set points. Furthermore, we suggest that changes in the metabolic rates of isolated cells probably occur within 24 h and involve a reduction of cellular metabolism toward values observed in lower metabolic rate organisms. The rate of oxygen delivery has been proposed to limit cellular metabolic rates in larger organisms. To examine the effect of oxygen on steady-state cellular respiration rates, we grew cells under a variety of physiologically relevant oxygen regimens. Long-term exposure to higher medium oxygen levels increased respiration rates of all cells, consistent with the hypothesis that higher rates of oxygen delivery in smaller mammals might increase cellular metabolic rates.

scholarly journals Allometry of mitochondrial efficiency is set by metabolic intensity

2019 ◽  
Vol 286 (1911) ◽  
pp. 20191693 ◽  
Author(s):  
Boël Mélanie ◽  
Romestaing Caroline ◽  
Voituron Yann ◽  
Roussel Damien
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Coupling Efficiency ◽  
Energy Output ◽  
Scaling Exponent ◽  
Metabolic Rates ◽  
Mammal Species ◽  
Skeletal Muscle Mitochondria ◽  
Metabolic Intensity ◽  
Mitochondrial Efficiency

Metabolic activity sets the rates of individual resource uptake from the environment and resource allocations. For this reason, the relationship with body size has been heavily documented from ecosystems to cells. Until now, most of the studies used the fluxes of oxygen as a proxy of energy output without knowledge of the efficiency of biological systems to convert oxygen into ATP. The aim of this study was to examine the allometry of coupling efficiency (ATP/O) of skeletal muscle mitochondria isolated from 12 mammal species ranging from 6 g to 550 kg. Mitochondrial efficiencies were measured at different steady states of phosphorylation. The efficiencies increased sharply at higher metabolic rates. We have shown that body mass dependence of mitochondrial efficiency depends on metabolic intensity in skeletal muscles of mammals. Mitochondrial efficiency positively depends on body mass when mitochondria are close to the basal metabolic rate; however, the efficiency is independent of body mass at the maximum metabolic rate. As a result, it follows that large mammals exhibit a faster dynamic increase in ATP/O than small species when mitochondria shift from basal to maximal activities. Finally, the invariant value of maximal coupling efficiency across mammal species could partly explain why scaling exponent values are very close to 1 at maximal metabolic rates.

scholarly journals Combined Effects of Acute Temperature Change and Elevated pCO2 on the Metabolic Rates and Hypoxia Tolerances of Clearnose Skate (Rostaraja eglanteria), Summer Flounder (Paralichthys dentatus), and Thorny Skate (Amblyraja radiata)

Biology ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 56 ◽  
Author(s):  
Schwieterman ◽  
Crear ◽  
Anderson ◽  
Lavoie ◽  
Sulikowski ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Gulf Of Maine ◽  
Standard Metabolic Rate ◽  
Hypoxia Tolerance ◽  
Intermittent Flow ◽  
Metabolic Rates ◽  
Summer Flounder ◽  
Paralichthys Dentatus ◽  
Clearnose Skate ◽  
Species Specific

Understanding how rising temperatures, ocean acidification, and hypoxia affect the performance of coastal fishes is essential to predicting species-specific responses to climate change. Although a population’s habitat influences physiological performance, little work has explicitly examined the multi-stressor responses of species from habitats differing in natural variability. Here, clearnose skate (Rostaraja eglanteria) and summer flounder (Paralichthys dentatus) from mid-Atlantic estuaries, and thorny skate (Amblyraja radiata) from the Gulf of Maine, were acutely exposed to current and projected temperatures (20, 24, or 28 °C; 22 or 30 °C; and 9, 13, or 15 °C, respectively) and acidification conditions (pH 7.8 or 7.4). We tested metabolic rates and hypoxia tolerance using intermittent-flow respirometry. All three species exhibited increases in standard metabolic rate under an 8 °C temperature increase (Q10 of 1.71, 1.07, and 2.56, respectively), although this was most pronounced in the thorny skate. At the lowest test temperature and under the low pH treatment, all three species exhibited significant increases in standard metabolic rate (44–105%; p < 0.05) and decreases in hypoxia tolerance (60–84% increases in critical oxygen pressure; p < 0.05). This study demonstrates the interactive effects of increasing temperature and changing ocean carbonate chemistry are species-specific, the implications of which should be considered within the context of habitat.

Developmental and seasonal changes in resting metabolic rates of captive female grey seals

1997 ◽  
Vol 75 (11) ◽  
pp. 1781-1789 ◽  
Author(s):  
Patrice Boily ◽  
David M. Lavigne
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Adult Female ◽  
Significant Relationship ◽  
Seasonal Changes ◽  
Resting Metabolic Rate ◽  
Halichoerus Grypus ◽  
Metabolic Rates ◽  
In Captivity ◽  
Predicted Values

Resting metabolic rate (RMR) data obtained from five juvenile and three adult female grey seals (Halichoerus grypus) in captivity over a period of 3.5 years were examined for developmental and seasonal changes. Three juveniles exhibited a significant relationship between log10 RMR and log10 mass, with individual slopes ranging from 0.42 to 1.62. Two of these exhibited a significant relationship between log10 RMR and log10 age. The remaining two juveniles and the three adults exhibited no significant relationship between RMR and body mass. With increasing size and age, RMRs of juveniles approached predicted values for adult mammals, but the large variation made it difficult to establish the precise age at which they achieved an adult-like RMR. RMRs of adults and juveniles exhibited marked seasonal changes. In juveniles, seasonal changes in RMR were limited to the annual moult, when the average RMR was 35% higher than during the rest of the year. In adults, changes in RMR were not limited to the time of the annual moult; rather, RMR was lower (by up to 50%) in the summer than during other seasons.

Field Metabolic-Rate and Food Requirement of a Small Dasyurid Marsupial, Sminthopsis-Crassicaudata

1988 ◽  
Vol 36 (3) ◽  
pp. 293 ◽  
Author(s):  
KA Nagy ◽  
AK Lee ◽  
RW Martin ◽  
MR Fleming
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Water Flux ◽  
Metabolic Rates ◽  
Feeding Rates ◽  
Doubly Labelled Water ◽  
Sminthopsis Crassicaudata ◽  
Food Requirement ◽  
Field Metabolic Rates ◽  
Free Ranging

Field metabolic rates (FMRs) and rates of water flux in free-ranging fat-tailed dunnarts, Sminthopsis crassicaudata, were measured during spring (late October) using doubly labelled water. Feeding rates were estimated on the basis of water and energy fluxes. FMRs averaged 68.7 kJ d-' in adults (mean body mass= 16.6 g), and were 29.2 kJ d-' in juveniles (6.1 g). These FMRs are 6.6 times basal metabolic rate (BMR), and are much higher than the hypothetical maxima of four to five times BMR. Other dasyurid marsupials also have high FMR/BMR ratios, but so does a small petaurid marsupial. S. crassicaudata consumed 80-90% of its body mass in arthropods each day. The diet of arthropods apparently provided enough water for the animals to maintain water balance without drinking during this study.

Relationship between body mass, tissue metabolic rate, and sodium pump activity in mammalian liver and kidney

1995 ◽  
Vol 268 (3) ◽  
pp. R641-R650 ◽  
Author(s):  
P. Couture ◽  
A. J. Hulbert
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Sodium Pump ◽  
Mammalian Species ◽  
Kidney Cortex ◽  
Tissue Metabolism ◽  
Pump Activity ◽  
Liver And Kidney ◽  
Cortex Slices ◽  
Kidney Cortex Slices

The allometric relationship between body mass and tissue metabolism was examined in liver and kidney cortex slices from mouse, rat, rabbit, sheep, and cattle, representing an approximately 12,000-fold difference in body mass and an 11-fold difference in mass-specific basal metabolic rate. Larger mammals have lower tissue metabolic rates (TMR; mumol O2.g wet wt-1.min-1) at 37 degrees C, yielding the equations TMR = 3.6 M-0.21 for liver slices and TMR = 3.2 M-0.11 for kidney cortex slices, where M is body mass in grams. This appears to be an intrinsic property of the tissue and is not due to differences in extracellular space or tissue protein content, because these are relatively constant in all mammalian species examined. The allometric relationships remain when tissue metabolism is expressed relative to "active cell mass" in tissue slices. Potassium uptake rate (KUR; mumol K+.g wet wt-1.min-1) was also measured (as 86Rb+ uptake) and was also lower in larger mammals, yielding the equations KUR = 1.2 M-0.14 in liver slices and KUR = 3.4 M-0.13 for kidney cortex slices. The energetic costs of sodium pump activity were estimated to be < 10% of TMR for liver and kidney cortex from all five mammalian species.

scholarly journals Mammalian Y RNAs are modified at discrete guanosine residues with N-glycans

2019 ◽  
Author(s):  
Ryan A. Flynn ◽  
Benjamin A. H. Smith ◽  
Alex G. Johnson ◽  
Kayvon Pedram ◽  
Benson M. George ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Secretory Pathway ◽  
Cultured Cells ◽  
Mammalian Species ◽  
Cell Types ◽  
Intramolecular Interactions ◽  
Small Noncoding Rnas ◽  
Select Group ◽  
Domains Of Life

ABSTRACTGlycans modify lipids and proteins to mediate inter- and intramolecular interactions across all domains of life. RNA, another multifaceted biopolymer, is not thought to be a major target of glycosylation. Here, we challenge this view with evidence that mammalian cells use RNA as a third scaffold for glycosylation in the secretory pathway. Using a battery of chemical and biochemical approaches, we find that a select group of small noncoding RNAs including Y RNAs are modified with complex, sialylated N-glycans (glycoRNAs). These glycoRNA are present in multiple cell types and mammalian species, both in cultured cells andin vivo. Finally, we find that RNA glycosylation depends on the canonical N-glycan biosynthetic machinery within the ER/Golgi luminal spaces. Collectively, these findings suggest the existence of a ubiquitous interface of RNA biology and glycobiology suggesting an expanded role for glycosylation beyond canonical lipid and protein scaffolds.

Seasonal variation in energy expenditure, water flux and food consumption of Arabian oryx Oryx leucoryx

2001 ◽  
Vol 204 (13) ◽  
pp. 2301-2311 ◽  
Author(s):  
Joseph B. Williams ◽  
Stéphane Ostrowski ◽  
Eric Bedin ◽  
Khairi Ismail
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Body Mass ◽  
Water Loss ◽  
Arid Zone ◽  
Water Flux ◽  
Metabolic Rates ◽  
Free Living ◽  
Evaporative Water ◽  
Arabian Oryx

SUMMARY We report on the energy expenditure and water flux, measured in the laboratory and in the field, of the Arabian oryx Oryx leucoryx, the largest desert ruminant for which measurements of the field metabolic rate of free-living individuals have been made using doubly labeled water. Prior to extirpation of this species in the wild in 1972, conservationists sequestered a number of individuals for captive breeding; in 1989, oryx were reintroduced in Saudi Arabia into Mahazat as-Sayd (2244km2). Apart from small pools of water available after rains, oryx do not have free-standing water available for drinking and therefore rely on grasses that they eat for preformed water intake as well as their energy needs. We tested whether oryx have a reduced fasting metabolic rate and total evaporative water loss (TEWL) in the laboratory, as do some other arid-adapted mammals, and whether oryx have high field metabolic rates (FMRs) and water influx rates (WIRs), as predicted by allometric equations for large arid-zone mammals. We measured FMR and WIR during the hot summer, when plant moisture content was low and ambient temperatures were high, and after winter rains, when the water content of grasses was high. For captive oryx that weighed 84.1kg, fasting metabolic rate averaged 8980kJday−1, 16.7% lower than predictions for Artiodactyla. Our own re-analysis of minimal metabolic rates among Artiodactyla yielded the equation: logV̇O2=−0.153+0.758logM, where V̇O2 is the rate of oxygen uptake in lh−1 and M is body mass in kg. Fasting metabolic rate of oryx was only 9.1% lower than predicted, suggesting that they do not have an unusually low metabolic rate. TEWL averaged 870.0mlday−1, 63.9% lower than predicted, a remarkably low value even compared with the camel, but the mechanisms that contribute to such low rates of water loss remain unresolved. For free-living oryx, FMR was 11076kJday−1 for animals with a mean body mass of 81.5kg during summer, whereas it was 22081kJday−1 for oryx in spring with a mean body mass of 89.0kg, values that were 48.6% and 90.4% of allometric predictions, respectively. During summer, WIR averaged 1310mlH2Oday−1, whereas in spring it was 3438mlH2Oday−1. Compared with allometric predictions, WIR was 76.9% lower than expected in summer and 43.6% lower in spring. We found no evidence to support the view that the WIR of large desert ungulates is higher than that of their mesic counterparts. On the basis of the WIR of the oryx averaged over the year and the water contents of plants in their diet, we estimated that an oryx consumes 858kg of dry matter per year.

scholarly journals Scaling of organ masses in mammals and birds: phylogenetic signal and implications for metabolic rate scaling

2019 ◽  
Author(s):  
Andrzej Antoł ◽  
Jan Kozłowski
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Phylogenetic Signal ◽  
Whole Body ◽  
Striking Difference ◽  
Metabolic Rates ◽  
Visceral Organs ◽  
Organ Tissue ◽  
The Brain

The persistent enigma of why the whole-body metabolic rate increases hypoallometrically with body mass should be solved on both the ultimate and proximate levels. The proximate mechanism may involve hyperallometric scaling of metabolically relatively inert tissue/organ masses, hypoallometric scaling of metabolically expensive organ masses, a decrease in mass-specific metabolic rates of organs or, more likely, a combination of these three factors. Although there are in data in the literature on the scaling of tissue/organ masses, they do not take phylogenetic information into account. Here, we analyse the scaling of tissue/organ masses in a sample of 100 mammalian species and 22 bird species with a phylogenetically informed method (PGLS) to address two questions: the role of phylogenetic signal in organ/tissue size scaling and the potential role of organ/tissue mass scaling in interspecific metabolic rate scaling. Strong phylogenetic signal was found for the brain, kidney, spleen and stomach mass in mammals but only for the brain and leg muscle in birds. Metabolically relatively inert adipose tissue scales isometrically in both groups. The masses of energetically expensive visceral organs scale hypoallometrically in mammals, with the exception of lungs, with the lowest exponent occurring for the brain. In contrast, only brain mass scales hypoallometrically in birds, whereas other tissues and organs scale isometrically or almost isometrically. Taking into account that the whole-body metabolic rate scales more steeply in mammals than in birds, the mass-specific metabolic rate of visceral organs must decrease with body mass at a much faster rate in birds than in mammals. To explain this striking difference, there is an urgent need to study the metabolic rates of tissues and organs to supplement measurements of the whole-body metabolic rate.

Limits and constraints in the scaling of oxidative and glycolytic enzymes in homeotherms

1988 ◽  
Vol 66 (5) ◽  
pp. 1128-1138 ◽  
Author(s):  
P. W. Hochachka ◽  
B. Emmett ◽  
R. K. Suarez
Keyword(s):  
Lactate Dehydrogenase ◽  
Body Mass ◽  
Citrate Synthase ◽  
Mammalian Species ◽  
Oxidative Capacity ◽  
Glycolytic Enzymes ◽  
Metabolic Rates ◽  
Muscle Lactate ◽  
Upper Limit ◽  
Oxidative And Glycolytic Enzymes

It is now empirically well established that basal and maximum rates of O2 uptake in homeotherms scale approximately to the 0.75 power; log–log plots of mass-specific metabolic rates versus body mass yield slopes of −0.20 to 0.25. Recent studies of 10 mammalian species and 1 hummingbird species indicate that marker enzymes of mitochondrial metabolism (citrate synthase, for example) scale inversely with body mass. Hummingbirds and shrews are near the upper limit in the degree to which the oxidative capacity of heart and skeletal muscles can be elevated; further increases in mitochondrial volume densities would sacrifice myofilament or sarcoplasmic reticulum volume densities. Whales weighing about 105 kg may be near the limit at the opposite extreme because their mass-specific resting metabolic rates are predicted to be approaching those of hypometabolic ectotherms. In contrast to oxidative enzyme scaling patterns, enzymes normally operative in muscle anaerobic glycolysis, such as lactate dehydrogenase, scale directly with body mass. Hummingbirds and shrews are considered to have reduced muscle lactate dehydrogenase levels near a lower limit commensurate with buffering of cytosolic redox, a distinctly aerobic lactate dehydrogenase function. How much anaerobic glycolytic potential can be packed into muscle cells in the largest mammals is unknown; this upper limit appears to be set by a compromise between myofilament volume densities and the combined volume densities of glycogen granules, intracellular buffering components, and glycolytic enzymes.

Developmental stage does not affect resting metabolic rate in the monitor lizard, Varanus salvator

2019 ◽  
Vol 69 (2) ◽  
pp. 199-212
Author(s):  
Yun-Tao Yao ◽  
Yu Du ◽  
Meng-Chao Fang ◽  
Long-Hui Lin ◽  
Xiang Ji
Keyword(s):  
Metabolic Rate ◽  
Developmental Stage ◽  
Body Mass ◽  
Significant Influence ◽  
Developmental Stages ◽  
Resting Metabolic Rate ◽  
Metabolic Rates ◽  
Mammal Species ◽  
Monitor Lizard ◽  
Varanus Salvator

Abstract We have studied resting metabolic rate (RMR) of the water monitor lizard (Varanus salvator) at different developmental stages (hatchling, juvenile and adult) to test whether individuals at different ages differ in RMR when controlling for the effects of body mass. We found that: 1) resting metabolic rates of hatchlings, juveniles and adults were all positively related to their body mass with the same coefficients and that 2) developmental stage had a non-significant influence on the resting metabolic rate when controlling for the effects of body mass. Our results suggest that variation in resting metabolic rate for V. salvator is directly caused by body mass differences, which conforms to previous findings in mammal species and birds.

Sign in / Sign up

Export Citation Format

Share Document