Tissue Respiration and Body Size

Bertalanffy, Ludwig von; Pirozynski, W. J.

doi:10.1126/science.113.2943.599

Cited by 30 publications

(8 citation statements)

References 7 publications

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“…The biphasic shape of the curve disappears if the oxygen uptake is referred to dry weight. While other tissues are known to respire less with increasing age (42,43), the drop is not as great as that reported here for nerves, with the possible exception of striated muscle (43).…”

Section: Biochemical and Morphologic Changes In Peripheral Nerves Andcontrasting

confidence: 53%

A Biochemical and Morphologic Study of Myelination and Demyelination

Majno

Karnovsky

1958

The Journal of Experimental Medicine

128

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Samples of normal grey matter, white matter, and peripheral nerves obtained from rats were incubated in Warburg vessels with glucose and a labelled lipide precursor (acetate, phosphate, choline, glycerol, glucose). The total lipides were then extracted and their radioactivity measured. The preparations were compared with respect to dry weight, lipide content, O2 uptake, and ability to incorporate the various substrates into the lipides. Grey matter was found to be the least damaged by incubation, white matter the most. Damage to the tissue depressed lipogenesis to a greater extent than respiration. Five substrates were compared with respect to their degree of incorporation into the lipides of the various preparations. White matter, which had a greater oxygen uptake than peripheral nerves, showed the lowest degree of incorporation for most of the substrates studied. The results suggest that there are considerable quantitative differences in the metabolism of central and peripheral myelin. In the sciatic preparations, oxygen uptake and lipogenesis from acetate were found to decrease from the proximal to the distal end of the nerve. This finding may be relevant to the pathogenesis of peripheral neuropathies. The growth and metabolic activity of peripheral nerves were studied in rats aged 1 to 500 days, and the biochemical and histological findings were correlated. The results indicated that the lipogenetic activity of the Schwann cell was lowest in the newborn animal, and reached its peak at about 20 days. Comparative data were also obtained from the cerebral cortex. The growth pattern of peripheral nerves was distinctly different from that of the brain. With respect to changes in tissue weight, respiration, and lipogenesis, growing peripheral nerve correlated with body weight, while the brain matured much more rapidly.

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Section: Biochemical and Morphologic Changes In Peripheral Nerves Andcontrasting

confidence: 53%

A Biochemical and Morphologic Study of Myelination and Demyelination

Majno

Karnovsky

1958

The Journal of Experimental Medicine

128

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“…Bertalanffy (1951) classified the growth patterns observed in animals according to their metabolic features. He questioned the relation between metabolism and size (Bertalanffy and Pirozynski, 1951), and studied the intra-and interspecies allometry (Bertalanffy and Pirozynski, 1952) and the quantitative aspects of growth in relation to the metabolism (Bertalanffy, 1957).…”

Section: A Model Of Von Bertalanffymentioning

confidence: 99%

Trajectories and models of individual growth

Karkach¹

2006

DemRes

135

104

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It has long been recognized that the patterns of growth play an important role in the evolution of age trajectories of fertility and mortality (Williams, 1957). Life history studies would benefit from a better understanding of strategies and mechanisms of growth, but still no comparative research on individual growth strategies has been conducted.Growth patterns and methods have been shaped by evolution and a great variety of them are observed. Two distinct patterns -determinate and indeterminate growth -are of a special interest for these studies since they present qualitatively different outcomes of evolution. We attempt to draw together studies covering growth in plant and animal species across a wide range of phyla focusing primarily on the noted qualitative features. We also review mathematical descriptions of growth, namely empirical growth curves and growth models, and discuss the directions of future research.1 Email: karkach@demogr.mpg.de http://www.demographic-research.org 347Karkach: Trajectories and models of individual growth IntroductionThe ontogenetic growth of an individual is intuitively understood to be an increase in the size of the whole organism or parts of it with age. But the very "natural" notion of growth is, in fact, very difficult to define. Living organisms are complex systems, consisting of parts that often grow at different rates and displaying different patterns. Some parts of the body may grow faster than others, some may stop growing at a certain stage while others continue to grow, and organs may grow "on demand" during regeneration. The cells of an organ may divide continuously throughout an organism's life, replacing aging cells and producing cell turn-over in the tissues; still the body size may remain constant. Growth is coordinated by a program of ontogenetic development that allows for variability in the development rates and sizes in order to adapt to environmental conditions. Size and growth rates are subject to evolutionary optimization and constraints. On the one hand, larger size usually leads to greater mating success, greater fertility, lower vulnerability to environmental hazards, and thus lower mortality. On the other, growth needs resources, and trades-off with other traits.Studies on growth and maintenance shed light on the problem of senescence. Most organisms experience cell turn-over in most tissues. Some organisms (e.g. hydra) apparently escape senescence due to a quick turn-over of cells (Martínez, 1998).Growth and body size are strongly related to other traits and fitness. Research on extant species showed a strong statistical relationship between body mass and a remarkable variety of biological features (Smith, 1996). Measures of growthGrowth as an increment in size can be measured in many different ways, each having advantages and drawbacks. An increase in mass or volume often can be measured easily, but may be only indirectly related to growth as increase in biomass. Organisms may change in content of water or fat, in mass and volume, but this i...

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“…G r a f e (1925) reported, moreover, that the tissue metabolism in vitro is more intensive than in vivo. More recent studies of arious authors (B e r t a 1 a n ffy & Pirozynski, 1951Pirozynski, , 1953Bertalanffy & Estwick, 1953; C r a nd a 11 & Smith, 1952; K 1 e i b e r, 1941; K r e b s, 1950; Schmidt-Nielsen, 1951) showed, however, that also in vitro some tissues isolated from small animals more intensive than in vivo. More recent studies of various authors (B e r t a 1 a n frespirate more intensively than those from large ones.…”

Section: Introductionmentioning

confidence: 97%

“…The relationship between the basal metabolic rate of adult homoiothermic animals and their body size may be described by the empirically established equation: M = kW' 4 (1) where M = basal metabolism rate, W = body weight in kilograms, k = proportionality coefficient representing the level of metabolism of a particular group of animals (K 1 e i b e r, 1947, 1961).…”

Section: Introductionmentioning

confidence: 99%

Metabolic rate of tissue slices of rats and rabbits as affected by age and body size

Jusiak

1969

Acta Theriol.

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The studies were carried out by the Warburg technique and the obtained results corrected after establishing by the method of C a s c ar a n o et al. what part of the incubated slices participates in the respiration. Most of the studied tissues from small animals showed higher metabolic rate than the homologous tissues derived from large animals, but the difference was less pronounced than that between basal metabolic rates. The estimated sum of tissue metabolism in young rats approached 100% of their basal metabolic rate, but in the case of adult rats this figure amounted only to 70%>. These results indicate that the metabolism of tissues in vitro is markedly different from their metabolism in vivo. In the author's opinion the main reason for this discrepancy lies in the fast disappearance of the effect of central regulating systems (nervous and humoral) on the metabolic processes occurring in cells of the isolated tissues.

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Tissue Respiration and Body Size

Cited by 30 publications

References 7 publications

A Biochemical and Morphologic Study of Myelination and Demyelination

A Biochemical and Morphologic Study of Myelination and Demyelination

Trajectories and models of individual growth

Metabolic rate of tissue slices of rats and rabbits as affected by age and body size

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