CO2 Output of Mice Measured by D2O18 Under Conditions of Isotope Re-entry Into the Body

1958 ◽  
Vol 195 (3) ◽  
pp. 721-725 ◽  
Author(s):  
Ruth McClintock ◽  
Nathan Lifson
Keyword(s):  
Material Balance ◽  
Body Water ◽  
The Body ◽  
Turnover Rates ◽  
Weight Changes ◽  
Body Weight Changes ◽  
Co2 Output ◽  
The Difference ◽  
Isotopic Turnover ◽  
Fractional Turnover

The fractional turnover rates of the hydrogen and oxygen of the body water of mice were measured in three ways: a) by material intake, b) by material output and c) isotopically. Discrepancies occurred between the intake and output turnover rates which could be explained at least in large part by body weight changes. The isotopic turnover rates were lower than those calculated from material output. This finding is discussed in relationship to the diarrhea which the animals developed on the milk diet employed and to the circumstance that opportunity was present for isotope re-entry from excreta. The difference between the turnover rates of the oxygen and hydrogen of the body water was practically the same whether obtained isotopically or calculated from the material balance data. This probably explains the observation that the D2O18 method for calculating the total CO2 output of the mice from the difference between the isotope turnover rates gave valid results in animals in which the absolute values for the isotopic turnover rates were presumably in error.

scholarly journals Doubly labelled water assessment of energy expenditure: principle, practice, and promise

2017 ◽  
Vol 117 (7) ◽  
pp. 1277-1285 ◽  
Author(s):  
Klaas R. Westerterp
Keyword(s):  
Energy Expenditure ◽  
Observation Interval ◽  
Energy Requirement ◽  
Dietary Assessment ◽  
Body Water ◽  
Assessment Methods ◽  
The Body ◽  
Turnover Rates ◽  
Doubly Labelled Water ◽  
The Difference

AbstractThe doubly labelled water method for the assessment of energy expenditure was first published in 1955, application in humans started in 1982, and it has become the gold standard for human energy requirement under daily living conditions. The method involves enriching the body water of a subject with heavy hydrogen (2H) and heavy oxygen (18O), and then determining the difference in washout kinetics between both isotopes, being a function of carbon dioxide production. In practice, subjects get a measured amount of doubly labelled water (2H 2 18 O) to increase background enrichment of body water for 18O of 2000 ppm with at least 180 ppm and background enrichment of body water for 2H of 150 ppm with 120 ppm. Subsequently, the difference between the apparent turnover rates of the hydrogen and oxygen of body water is assessed from blood-, saliva-, or urine samples, collected at the start and end of the observation interval of 1–3 weeks. Samples are analyzed for 18O and 2H with isotope ratio mass spectrometry. The doubly labelled water method is the indicated method to measure energy expenditure in any environment, especially with regard to activity energy expenditure, without interference with the behavior of the subjects. Applications include the assessment of energy requirement from total energy expenditure, validation of dietary assessment methods and validation of physical activity assessment methods with doubly labelled water measured energy expenditure as reference, and studies on body mass regulation with energy expenditure as a determinant of energy balance.

scholarly journals Features of body weight growth in meat breeds heifers

2016 ◽  
Vol 18 (2) ◽  
Author(s):  
R. S. Oseredchuk ◽  
N. P. Babik ◽  
V. V. Fedorovych ◽  
E. I. Fedorovych ◽  
V. R. Dutka
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Weight Changes ◽  
Body Weight Changes ◽  
Relative Growth ◽  
Weight Growth ◽  
Rate Of Increase ◽  
The Difference ◽  
Tension Increase ◽  
Better Than

The data on the dynamics of body weight changes, absolute and average daily gains, frequency rate of increase in body weight, relative growth rate and intensity of body weight growth of Limousine and Volyn Meat breeds heifers. Both studied breeds characterized by different body weight at different age periods. Newborn Limousine breed heifers are weighed 2,7 kg more (P < 0.05) than Volyn Meat breed heifers; at 3 months age the difference was 8.5 kg (P < 0.05) at 6 months – 14.6 kg, at 9 month – 20.8 kg (P < 0.05), at 12 months – 25,6 kg (P < 0.05), at 15–months – 31.9 (P<0,05), and at 18 months – 23.5 kg. Total and average daily gains in animals of both breeds were the highest for a period of 3 to 6 months of age. In the period from birth to 15 months of age preference for average daily gains were in Limousine, however, the difference was statistically significant only for the period of 0 – 3 months and amounted to 63,9 g (P < 0,05). From 15 to 18 months of age Limousine slightly conceded to Volyn Meat breeds on this parameter. In animals of both breeds magnification of body weight increased with age, but over the entire period (from birth to 18 months) this parameter in Volyn Meat heifers was 0.6 times better than Limousine heifers. The coefficients of relative intensity and tension increase of body weight in animals of both breeds were highest in the period from birth to 3 months of age. With age, these indicators declined. Mainly, the advantage was in Volyn meat breed heifers, but the difference was not statistically significant.

Measurement of total energy and material balance in rats by means of doubly labeled water

1960 ◽  
Vol 199 (2) ◽  
pp. 238-242 ◽  
Author(s):  
J. S. Lee ◽  
Nathan Lifson
Keyword(s):  
Body Weight ◽  
Water Intake ◽  
Material Balance ◽  
Body Water ◽  
Doubly Labeled Water ◽  
Final Body Weight ◽  
Water Output ◽  
Isotopic Analyses ◽  
The Difference ◽  
Metabolism Chamber

A test has been carried out in rats of the possibility of measuring with the aid of doubly labeled water (D2O18) the following components of the material balance of an animal: output of CO2 and water; intake of oxygen, food and water. The items of information used for the measurement were a) isotopic analyses of initial and final blood samples, b) composition of the diet with respect to percentage protein, carbohydrate and fat, c) initial and final body weight, d) final percentage body water. Initial percentage body water obtained from a by the volume of dilution principle could substitute for d. CO2 and water output were estimated isotopically; O2 consumption, from the CO2 output and dietary R. Q.; food intake, from CO2 output and dietary composition; water intake, from the difference between water output and dietary metabolic water. A rough correction for storage of materials was made from the change in body weight. The average difference between observed values for each of the above components of the material balance and values calculated by the isotope procedure was less than 10%. The fact that dry air was supplied to the animal in the metabolism chamber used to obtain the observed values probably favored better agreement between calculated and observed values for water intake and output than would prevail in ordinary moist air.

Effects of altitude acclimatization on rat myoglobin. Changes in myoglobin content of skeletal and cardiac muscle

1959 ◽  
Vol 196 (3) ◽  
pp. 512-516 ◽  
Author(s):  
Adam Anthony ◽  
Eugene Ackerman ◽  
G. K. Strother
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Cardiac Muscle ◽  
Water Content ◽  
Skeletal Muscles ◽  
The Body ◽  
Continuous Exposure ◽  
Weight Changes ◽  
Body Weight Changes ◽  
Muscle Weight

Analyses were made of myoglobin content of rat skeletal and cardiac muscle following continuous exposure to simulated altitudes of 18,000 feet for a 2–10-week period. About five dozen rats were used. Acclimatization was associated with an increase in the myoglobin concentration of thigh, diaphragm, gastrocnemius and heart muscles. Total myoglobin content, however, increased during acclimatization in cardiac muscle but not in the three skeletal muscles. This finding together with the body weight changes and muscle weight changes suggested that the increases in myoglobin concentration of skeletal muscle may be merely a reflection of a decreased water content of muscles.

D2 18O (deuterium oxide) method for CO2 output in small mammals and economic feasibility in man

1975 ◽  
Vol 39 (4) ◽  
pp. 657-664 ◽  
Author(s):  
N. Lifson ◽  
W. S. Little ◽  
D. G. Levitt ◽  
R. M. Henderson
Keyword(s):  
Small Mammals ◽  
Deuterium Oxide ◽  
Body Water ◽  
Economic Feasibility ◽  
The Body ◽  
Doubly Labeled Water ◽  
Co2 Output ◽  
Isotopic Analyses ◽  
Human Energy ◽  
Intake Water

A test of the validity of the isotopic steady state relationships of the doubly labeled water (H2O) method has been carried out with D2 18O in small mammals (three chipmunks and one mouse). CO2 outputs calculated just from 1) the rate of water intake and 2) the ratios of the isotopic concentrations in the body water to the intake water agreed satisfactorily with observed values. Moreover, reconstructed energy and material balances agreed reasonably with similar balances reconstructed for an immediately succeeding period on the same animals studied by the previously validated decay procedure. We conclude from an error analysis that by expressing the isotopic specific activities as abundances in excess of the body water of a subject on a given regimen, the decay procedure is economically feasible in the human with available accuracy of isotopic analyses and the present cost of H2 18O. The method therefore appears to be a useful tool ready for application to the field of human energy metabolism.

Glutamine and glutamate kinetics in humans

1986 ◽  
Vol 251 (1) ◽  
pp. E117-E126 ◽  
Author(s):  
D. Darmaun ◽  
D. E. Matthews ◽  
D. M. Bier
Keyword(s):  
Venous Blood ◽  
The Body ◽  
Glutamine Metabolism ◽  
Whole Body ◽  
Turnover Rates ◽  
Healthy Young Adult ◽  
Appearance Rate ◽  
N Rates ◽  
Male Subjects ◽  
Fractional Turnover

To study glutamate and glutamine kinetics, 4-h unprimed intravenous infusions of L-[15N]glutamate, L-[2-15N]glutamine, and L-[5-15N]-glutamine were administered to healthy young adult male subjects in the postabsorptive state. Arterialized-venous blood samples were drawn and analyzed for glutamate and glutamine 15N enrichments. The fractional turnover rates of the tracer-miscible glutamate and glutamine pools were fast, 8.0 and 2.8% min-1, respectively. The glutamate tracer-miscible pool accounted for less than one-tenth the estimated free glutamate pool in the body. The plasma glutamate amino N, glutamine amino N and glutamine amide N rates of appearance were 83 +/- 22 (means +/- SD), 348 +/- 33, and 283 +/- 31 mumol X kg-1 X h-1, respectively. The glutamine amide N appearance rate was 20% slower than the amino N appearance rate, indicating that glutamine transaminase is an active pathway in human glutamine metabolism. From measurement of transfer of tracer 15N, we found that only 5% of the glutamine synthesized in cells and released into plasma was derived from intracellular glutamate that had mixed with plasma. These data demonstrate that intravenously administered tracers of glutamate or glutamine do not mix thoroughly with the intracellular pools, and their measured kinetics reflect transport rates through plasma rather than whole-body fluxes.

scholarly journals Feeding and Excretion in the Scorpion Paruroctonus Mesaensis: Water and Material Balance

1984 ◽  
Vol 110 (1) ◽  
pp. 253-265
Author(s):  
STANLEY D. YOKOTA
Keyword(s):  
Water Intake ◽  
Material Balance ◽  
Body Water ◽  
The Body ◽  
Nitrogen Excretion ◽  
Fluid Uptake ◽  
Direct Measurements ◽  
Pharyngeal Pumping ◽  
Almost All ◽  
Minimal Estimate

Scorpions feed by a process involving the external grinding and digestion of prey, with the ingestion of only the soluble fraction. The water obtained from the prey represents the most important source of water intake for scorpions inhabiting arid regions, placing great importance on the animals' ability to utilize prey water effectively. The scorpion Paruroctonus mesaensis (Stahnke) was found to ingest a mean of 88% of the body water of selected prey. However, the scorpion loses 0.37 ml of its own body water per ml of prey water extracted, resulting in a net water gain of 0.51 ml water for every ml of prey water. Fluid uptake by the scorpion has been ascribed to a pharyngeal pumping mechanism. Direct measurements of the suction generated by the pharynx yielded a minimal estimate of its pumping capability of 130mmHg. The uptake and excretion of nitrogen and electrolytes by Paruroctonus mesaensis on a diet of Tenebrio molitor adults were also analysed. Almost all the potassium ingested was excreted, whereas most of the sodium and chloride were retained, possibly serving to expand haemolymph volume. Assuming a steady state for nitrogen, it was estimated that the net utilizable water obtained from prey, that is the water intake minus the excretory water necessitated by nitrogen excretion, was equivalent to about 35% of the initial prey water or 69% of the water ingested.

Water content and water turnover in beef cattle

1968 ◽  
Vol 19 (1) ◽  
pp. 129
Author(s):  
PH Springell
Keyword(s):  
Water Content ◽  
Half Life ◽  
Turnover Rate ◽  
Tritiated Water ◽  
Body Water ◽  
The Body ◽  
Turnover Rates ◽  
Water Turnover ◽  
Poor Diet ◽  
The Mean

Twenty-four steers, comprising British (Hereford and Hereford x Shorthorn), Zebu (Africander), and Zebu cross (British x Brahman or Africander) breeds, were either maintained on pasture, or yarded and fed on diets of a low and a high nutritional value. Tritiated water was injected into the animals on five occasions at intervals of 3 months. The body water content and the water turnover rate were calculated, and some of the sources of variation defined. Observed differences in the water content are attributable to nutritional factors rather than to breed differences. The mean body water content ranged from 615 to 809 ml/kg fasting body weight, where the higher values were associated with a poor diet. The mean half-life of tritiated water was lower in summer (as low as 58 hr) than in winter (up to 128 hr) in grazing and well-fed yarded steers. On a poor diet, however, the half-life in yarded cattle remained high and almost constant throughout the year, dropping to below 100 hr on only a single occasion. Occasionally the half-life was breed dependent, but generally no significant differences between breeds could be found. While mean turnover rates of up to 7.1 ml kg-1 hr-1 were found in better-fed cattle in summer, the value in poorly fed animals was almost constant throughout the year at about 3.3 ml kg-1 hr-1. There was, however, a winter minimum in the well-fed yarded and grazing groups. The turnover rate was also influenced by breed only to a limited extent. The results are interpreted in the light of their possible significance in the adaptation to a tropical environment, and in relation to their value in predicting the body composition.

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