The respiratory exchange of animals and man

Krogh, August

doi:10.5962/bhl.title.26229

Cited by 295 publications

(196 citation statements)

References 30 publications

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“…This term was of great value to the early investigators, as it emphasised the need to conduct experiments under strictly standardized conditions. Krogh (1916) proposed the term`standard metabolism' to circumvent the erroneous impression that basal metabolism is the lowest resting metabolism, ie the lowest that could be obtained by an individual. Although the term`standard metabolism' has not gained universal usage, the meaning of basal metabolism has been widely accepted.…”

Section: Historical Overviewmentioning

confidence: 99%

Mechanisms of changes in basal metabolism during ageing

Henry

2000

Eur J Clin Nutr

105

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A considerable number of physiological functions are known to show a gradual decline with increasing age. However, the effects of ageing differ widely between organ systems. It is believed that basal metabolic rate (BMR) falls dramatically with age. These observations, largely based on cross-sectional surveys, are discussed in light of our present understanding of the biology of ageing. This paper reviews both the longitudinal and crosssectional studies of BMR and presents evidence that the fall in BMR with ageing may be less dramatic than previously perceived. Indeed, some subjects may show an increase in BMR with ageing. The mechanism of changes in BMR during ageing will be discussed. Organ weight changes appear to have a profound impact on BMR. The use of BMR to predict total energy expenditure in the`old elderly' ( b 75 y) is unlikely to be of any practical use due to wide intra-and inter-individual variation in BMR. This wide intra-and inter-individual variation in BMR is due to illness, disease and other metabolic disorders seen in the elderly. Finally, the importance of measuring BMR in elderly populations for its use in clinical medicine will be discussed. Descriptors: aging; basal metabolic rate; body composition

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Section: Historical Overviewmentioning

confidence: 99%

Mechanisms of changes in basal metabolism during ageing

Henry

2000

Eur J Clin Nutr

105

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“…Much overlooked in this debate are the well-established effects of body temperature on whole organism metabolic rate (Krogh 1916;Gillooly et al 2001), and how such effects may influence brain size. If in fact brain size is constrained by metabolic rate, then one might expect brain size to increase exponentially with temperature in the same way as metabolic rate.…”

Section: Introductionmentioning

confidence: 99%

Hotter is Smarter: The temperature-dependence of brain size in vertebrates

Gillooly

2013

Preprint

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View the peer-reviewed version (peerj.com/articles/301), which is the preferred citable publication unless you specifically need to cite this preprint. Hotter is Smarter: The temperature-dependence of brain size in vertebratesThe tremendous variation in brain size among vertebrates has long been thought to be related to differences in species' metabolic rates. Species with higher metabolic rates can supply more energy to support the relatively high cost of brain tissue. And yet, while body temperature is known to be a major determinant of metabolic rate, the possible effects of temperature on brain size have scarcely been explored. Thus, here I explore the effects of temperature on brain size among diverse vertebrates (fishes,amphibians, reptiles, birds and mammals). I find that, after controlling for body size,brain size increases exponentially with temperature in much the same way asmetabolic rate. These results suggest that temperature-dependent changes inaerobic capacity, which have long been known to affect physical performance, similarly affect brain size. The observed temperature-dependence of brain size may explain observed gradients in brain size among both ectotherms and endotherms across broad spatial and temporal scales.PeerJ PrePrints | https://peerj.com/preprints/155v1/ | v1

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“…It is appropriate that energy expenditure should be the subject for three Classics in Obesity, because it has been the subject of study for more than two centuries (1,8,11,12,15,17,(24)(25)(26)(27)29,38,4145,52,57).…”

Section: Calorimetrymentioning

confidence: 99%

Engergy Expenditure Using Doubly Labeled Water: The Unveiling of Objective Truth

Ga¹

1997

Obesity Research

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Blessed is he who maketh due proofe. With due proofe and with discreet assaye Wise men may learn new things every day. Thomas Norton (b. 1493) in Ordinall of Alkimy.Only one paper has been selected for this issue of Classics in Obesity. It is entitled "The original use of doubly labeled water to measure energy expenditure in animals," by Lifson et al. (36). This paper is important because it provides an insight into the possibility of a new method of indirectly quantitating the expenditure of energy in freeliving animals and human beings. Energy expenditure from the metabolism of ingested food or body nutrient stores is onehalf of the equation for energy balance articulated in the 19th century as the First Law of Thermodynamics or the principle that energy is conserved. However, this law did not pull back the veil of objective truth sufficiently for the work of Lifson et al. (36). Their work required several additional unveilings of basic metabolism and isotope chemistry that were not possible until the mid-20th century. I will first review the development of calorimetry, followed by the use of doubly labeled water. CalorimetryIt is appropriate that energy expenditure should be the subject for three Classics in Obesity, because it has been the subject of study for more than two centuries (1,8,11,12,15,17,(24)(25)(26)(27)29,38,4145,52,57).The paper by Lavoisier and LaPlace (31) was the first in this series dealing with energy expenditure (10). Lavoisier and LaPlace, in parallel with Crawford (12) in the late 18th century, developed direct calorimeters and applied them to measuring heat loss in animals. Although they both showed the similarity of metabolism to a slow combustion, Lavoisier discovered the concept of oxidation which overthrew the previously entrenched phlogiston theory of Stahl (55).The second paper on energy expenditure in this series was from Atwater and Benedict (9). Atwater and Benedict (4) and Rubner (52) independently demonstrated that the First Law of Thermodynamics, formulated by Mayer (40) and Helmholtz (20), applied to both animals and human beings.New methods are one of the cornerstones for advances in science. The discovery of the microscope (32), the introduction of radioactive isotopes (2 1) into clinical medicine, and the development of the radio-immunoassay for hormones (7) are but three in a long list. This paper is about another method that was originally developed in animals and then applied to the study of energy expenditure in human beings with substantial new discoveries.The first two calorimeters were those of Lavoisier and LaPlace (31) and Crawford (12). Crawford measured the heat given off by his guinea pigs as the temperature increased the water surrounding the cage. Lavoisier and LaPlace used the melting of ice surrounding the cage of their guinea pigs to determine heat production. The oxygen theory that resulted from Lavoisier's work provided the basis for indirect calorimetry. Among other firsts, Lavoisier conducted the first study of human metabolism by measuring the oxy...

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The respiratory exchange of animals and man

Cited by 295 publications

References 30 publications

Mechanisms of changes in basal metabolism during ageing

Mechanisms of changes in basal metabolism during ageing

Hotter is Smarter: The temperature-dependence of brain size in vertebrates

Engergy Expenditure Using Doubly Labeled Water: The Unveiling of Objective Truth

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