On Factors Influencing the Gas-Exchange in Fish

1946 ◽  
Vol 7 (1) ◽  
pp. 1-15 ◽  
Author(s):  
A. Punt ◽  
J. Jongbloed
Keyword(s):  
Body Weight ◽  
Gas Exchange ◽  
Metabolic Rate ◽  
Surface Area ◽  
Salt Concentration ◽  
Optimum Temperature ◽  
Influence Of Temperature ◽  
Factors Influencing ◽  
Maximum Value ◽  
Area Law

AbstractI. Using a new method in which fishes were kept in their natural circumstances the metabolic rate of these was established by means of the diaferometer-technique. 2. The relation between the size of fish and the rate of gas-exchange per unit of body weight could be affirmed. The surface-area-law is discussed. 3. The influence of temperature is studied; the Q, 10 has probably a maximum value at optimum temperature. 4. The influence of CO2- and O2-pressure is discussed. Most fishes did not react at i oo % O2; at lower pressures a higher metabolic rate may be found, due to increased fidget of the animals. 5. Salt concentration probably is more important than pH of the water as to metabolic rate of fishes. 6. No results were obtained as to the influence of thyroxin and progesteron, added to the water, on the metabolism of Rhodeus amarus L.

Factors Influencing Survival of Rats in Fasting

1957 ◽  
Vol 188 (2) ◽  
pp. 332-336 ◽  
Author(s):  
R. H. Rixon ◽  
J. A. F. Stevenson
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Metabolic Rate ◽  
Environmental Temperature ◽  
Body Weight Loss ◽  
Initial Body Weight ◽  
Adult Rats ◽  
Factors Influencing ◽  
The Individual ◽  
Intact Rats

The individual duration of survival of adult rats in complete fasting varied considerably; the range at an environmental temperature of 22°C was 6–16 days, at 2–5°C, 1–7 days, and in thyroidectomized animals at 22°C, 15–25 days. This variation in survival was not closely related to the initial body weight but was related to the individual proportionate body weight loss per day and the total proportionate weight loss sustained before death. The individual proportionate rate of weight loss has been correlated with the metabolic rate indicating that the former reflected the metabolic rate of the animal. The duration of survival in fasting has been correlated with the individual metabolic rate, whether measured before or during fasting. Since fasting did not obliterate or reduce the individual differences in metabolic rate, it was possible to predict the individual duration of survival from knowledge of the prefasting metabolic rate. The total proportionate weight loss, which also influenced the survival time in fasting, was altered by changes in the environmental temperature and probably by other factors. The previous diet whether high in protein, fat or carbohydrate had little effect on the duration of survival. Fasting caused a decrease in the metabolic rate of intact rats at 22°C but no change in that of thyroidectomized rats or of rats living in the cold.

scholarly journals The scaling and potential importance of cutaneous and branchial surfaces in respiratory gas exchange in young chinook salmon (oncorhynchus tshawytscha)

1990 ◽  
Vol 154 (1) ◽  
pp. 1-12 ◽  
Author(s):  
PETER J. ROMBOUGH ◽  
BRENDA M. MOROZ
Keyword(s):  
Gas Exchange ◽  
Metabolic Rate ◽  
Surface Area ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Total Surface Area ◽  
Tissue Mass ◽  
Respiratory Gas Exchange ◽  
Yolk Absorption ◽  
Gill Lamellae

Measurements were made of the surface areas of the yolk sac, the fins, the head and trunk, the gill filaments and the gill lamellae of chinook salmon (Oncorhynchus tshawytscha Walbaum) weighing between 0.045 g (3.7 days posthatch) and 13.4g (180 days posthatch). Cutaneous surfaces initially accounted for the vast majority (approx. 96%) of the total area available for respiratory gas exchange. As fish grew, total branchial surface area expanded at a more rapid rate than cutaneous surface area and, thus, came to represent a progressively larger fraction of total surface area. The transition was relatively slow, however, and it was not until fish reached 2.5-4.0 g that branchial area exceeded cutaneous area. Although some individual surfaces (e.g. the gill lamellae) followed rather complex patterns of expansion, the overall increase in respiratory surface area with tissue mass could be described reasonably well using only two equations; one for the period prior to complete yolk absorption (<0.4 g) and one for the period following complete yolk absorption (>0.4 g). Mass exponents for total surface area (b = 0.85) and metabolic rate (b = 0.8-0.9) were not significantly different for the larger fish. In contrast, the mass exponent for total surface area (b = 0.39) was significantly less than that for metabolic rate (b ≈ 0.9-1.0) for fish weighing less than 0.4 g. Changes in the relative efficiencies of the various exchange surfaces during the course of larval development probably account for this discrepancy.

Postnatal lung function in the developing rat

2008 ◽  
Vol 104 (4) ◽  
pp. 1167-1176 ◽  
Author(s):  
Ines Bolle ◽  
Gunter Eder ◽  
Shinji Takenaka ◽  
Koustav Ganguly ◽  
Stefan Karrasch ◽  
...  
Keyword(s):  
Body Weight ◽  
Lung Function ◽  
Gas Exchange ◽  
Surface Area ◽  
Lung Volume ◽  
Structural Changes ◽  
Rat Lung ◽  
Postnatal Maturation ◽  
Old Rats ◽  
Developing Rat

Little is known about lung function during early stages of postnatal maturation, although the complex structural changes associated with developing rat lung are well studied. We therefore analyzed corresponding functional (lung volume, respiratory mechanics, intrapulmonary gas mixing, and gas exchange) and structural (alveolar surface area, mean linear intercept length, and alveolar septal thickness) changes of the developing rat lung at 7–90 days. Total lung capacity (TLC) increased from 1.54 ± 0.07 to 16.7 ± 2.46 (SD) ml in proportion to body weight, but an increase in body weight exceeded an increase in lung volume by almost twofold. Series dead space volume increased from 0.21 ± 0.03 to 1.38 ± 0.08 ml but decreased relative to TLC from 14% to 8%, indicating that parenchymal growth exceeded growth of conducting airways. Diffusing capacity of CO (Dco) increased from 8.1 ± 0.8 to 214.1 ± 23.5 μmol·min−1·hPa−1, corresponding to a substantial increase in surface area from 744 ± 20 to 6,536 ± 488 cm2. Dco per unit of lung volume is considerably lower in the immature lung, inasmuch as Dco/TLC in 7-day-old rats was only 42% of that in adult (90 day-old) rats. In humans, however, infants and adults show comparable specific Dco. Our functional and structural analysis shows that gas exchange is limited in the immature rat lung. The pivotal step for improvement of gas exchange occurs with the transition from bulk alveolarization to the phase of expansion of air spaces with septal reconstruction and microvascular maturation.

Estimating doses for children

1963 ◽  
Vol 1 (18) ◽  
pp. 69-70
Keyword(s):  
Body Weight ◽  
Metabolic Rate ◽  
Surface Area ◽  
Vitamin K ◽  
Simple Formula ◽  
Empirical Relationship ◽  
Extracellular Fluid ◽  
The Body ◽  
Clear Cut ◽  
Young Infants

No simple formula relating dose to age or body weight has proved satisfactory. The reason is that the dose is largely determined by factors such as lean body mass, extracellular fluid volume and metabolic rate, none of which are linearly related to weight. These factors happen to be much more closely related to the surface area of the body, and many paediatricians use this empirical relationship to estimate doses for children. When this method is used children are seen to be neither more nor less sensitive to most drugs than adults. The few clear-cut exceptions are particularly important in the newborn and in young infants, who are for example less sensitive than adults to phenobarbitone and perhaps other barbiturates, and more sensitive than adults to sulphonamides, opiates, vitamin K analogues, and various antibiotics.

scholarly journals The Surface-Area/Body-Weight Relationship in Mice

1967 ◽  
Vol 20 (3) ◽  
pp. 687 ◽  
Author(s):  
NJ Dawson
Keyword(s):  
Body Weight ◽  
Metabolic Rate ◽  
Recent Work ◽  
Surface Area ◽  
Clinical Studies ◽  
Weight Basis ◽  
Weight Relationship ◽  
Area Basis ◽  
History Of ◽  
Surface Area Basis

Since Sarrus and Remeaux (see Kleiber 1961, p. 180) first proposed a "surface law", the measured or calculated surface area of animals has been used by many workers as a basis for comparison between individuals and between species in studies of metabolic rate. The history of the surface law has been discussed by Kayser (1951) and by Kleiber (1961). The DuBois standards for determining the surface area of humans have served for many years as a valuable basis for comparison between individuals in physiological and clinical studies of metabolic rate. However, standards similar to the DuBois standards for humans do not exist for other species. The trend in recent work on metabolic rate of animals appears to be to make comparisons on a body-weight basis rather than on a surface-area basis. The work reported in this paper was designed to investigate the usefulness of surface area as a basis for comparison in some studies on metabolic rate of mice.

Some consequences of body size

1984 ◽  
Vol 247 (4) ◽  
pp. H495-H507 ◽  
Author(s):  
L. E. Ford
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Metabolic Rate ◽  
Muscle Power ◽  
Weight Ratio ◽  
Single Species ◽  
Hill Climbing ◽  
Proper Size ◽  
Higher Power ◽  
Metabolic Indices

The question of the proper size denominator for metabolic indices is addressed. Metabolic rate among different species is proportional to the 3/4 power of body weight, not surface area. Muscle power also varies with the 3/4 power of weight, suggesting that metabolic rate is determined mainly by muscle power. Power-to-weight ratio, specific metabolic rate, and a number of metabolic periods, including heart rate, all vary inversely with the 1/4 power of body weight. Thus the relative times required for physiological and pathological processes in different species may be estimated from the average resting heart rate for the species. There are not many small humans among athletic record holders in events involving acceleration and hill climbing, as would be expected if they had higher power-to-weight ratios. Thus the relationship between size and metabolic rate in different species should not be applied within the single species of humans. Evidence is reviewed showing that basal metabolic rate in humans is determined mainly by lean body mass.

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