Breath water-based doubly labelled water method for the noninvasive determination of CO2 production and energy expenditure in mice

2018 ◽  
Vol 54 (6) ◽  
pp. 561-572 ◽  
Author(s):  
Peter Junghans ◽  
Solvig Görs ◽  
Martina Langhammer ◽  
Cornelia C. Metges
Keyword(s):  
Energy Expenditure ◽  
Co2 Production ◽  
Doubly Labelled Water ◽  
Water Based

scholarly journals Energy expenditure of free-living reindeer estimated by the doubly labelled water method

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 211 ◽  
Author(s):  
Geir Gotaas ◽  
Eric Milne ◽  
Paul Haggarty ◽  
Nicholas J.C. Tyler
Keyword(s):  
Energy Expenditure ◽  
Rangifer Tarandus ◽  
Water Flux ◽  
Co2 Production ◽  
Wild Ungulates ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Svalbard Reindeer ◽  
Mountain Pasture ◽  
The Mean

The doubly labelled water (DLW) method was used to measure total energy expenditure (TEE) in three male reindeer (Rangifer tarandus tarandus) aged 22 months in winter (February) while the animals were living unrestricted at natural mountain pasture in northern Norway (69°20'N). The concentrations of 2H and l8O were measured in water extracted from samples of faeces collecred from the animals 0.4 and 11.2 days after injection of the isotopes. Calculated rates of water flux and CO2-production were adjusted to compensate for estimated losses of 2H in faecal solids and in methane produced by microbial fermentation of forage in the rumen. The mean specific TEE in the three animals was 3.057 W.kg-1 (range 2.436 - 3.728 W.kg1). This value is 64% higher than TEE measured by the DLW method in four captive, non-pregnant adult female reindeer in winter and probably mainly reflects higher levels of locomotor activity in the free-living animals. Previous estimates of TEE in free-living Rangifer in winter based on factorial models range from 3.038 W.kg-1 in female woodland caribou (R. t. caribou) to 1.813 W.kg-1 in female Svalbard reindeer (R. t. platyrhynchus). Thus, it seems that existing factorial models are unlikely to overestimate TEE in reindeer/caribou: they may, instead, be unduly conservative. While the present study serves as a general validation of the factorial approach, we suggest that the route to progress in the understanding of field energetics in wild ungulates is via application of the DLW method.

Application of the Fick principle to the continuous measurement of energy expenditure in pigs

1993 ◽  
Vol 44 (7) ◽  
pp. 1423
Author(s):  
LR Giles ◽  
JM Gooden
Keyword(s):  
Heat Exchange ◽  
Energy Expenditure ◽  
Continuous Measurement ◽  
Open Circuit ◽  
Growing Pigs ◽  
Whole Body ◽  
Co2 Production ◽  
Entry Rate ◽  
Doubly Labelled Water ◽  
Fick Principle

The paper reviews the current methods available for the measurement of heat exchange in pigs. The cost of construction of automated open-circuit respiration chambers, in association with climate-controlled facilites, has restricted continuous measurement of energy expenditure in pigs to a small number of laboratories around the world. Ventilated hoods and face mask techniques are not viable alternatives because of difficulties in maintaining a uniform environment around the animal and restriction of food intake. Indirect techniques, including carbon dioxide (CO2) entry rate and doubly-labelled water are only applicable when other technique are not available because of the errors involved when energy expenditure is based on CO2 production alone. An alternative procedure is described for the measurement of energy expenditure in the growing pig. Whole-body oxygen (O2) consumption is calculated from the product of cardiac output and the arteriovenous difference in blood O2 concentration across the lungs (Fick principle). Oxygen consumption recorded with the new procedure was compared with the ventilated hood and CO2 entry-rate techniques, and used to examine the heat exchange of growing pigs maintained at high ambient temperatures

scholarly journals Studies on the mechanism of the antifungal action of benzoate

1983 ◽  
Vol 214 (3) ◽  
pp. 657-663 ◽  
Author(s):  
H A Krebs ◽  
D Wiggins ◽  
M Stubbs ◽  
A Sols ◽  
F Bedoya
Keyword(s):  
Intracellular Ph ◽  
Intracellular Water ◽  
Co2 Production ◽  
Glucose Fermentation ◽  
Water Based ◽  
Antifungal Action ◽  
Inhibition Of Glycolysis ◽  
Cellular Water ◽  
External Ph

A method is described for the determination of the pH of intracellular water based on the distribution of [14C]benzoate (0.01 mM) between intra- and extra-cellular water. Benzoate at higher concentrations (2-10mM) enters the yeast cell in the undissociated form, and its neutralization within the cell can cause a shift of the pH of the intracellular water by more than 1 pH unit. Benzoate causes an accumulation of the two hexose monophosphates of yeast glucose fermentation and a decrease in intermediates beyond phosphofructokinase, suggesting inhibition at this stage. Benzoate also causes a concomitant fall in [ATP]. Phosphofructokinase is inhibited to a greater extent than hexokinase at acid pH. There is a relationship between intracellular pH, phosphofructokinase inhibition and CO2 production, suggesting that the antifungal action of benzoate is caused by an accumulation of benzoate at low external pH, which lowers the intracellular pH into the range where phosphofructokinase is sensitive. The subsequent inhibition of glycolysis causes a fall in [ATP] and thus restricts growth.

Increased leucine flux and leucine oxidation during the luteal phase of the menstrual cycle in women

1994 ◽  
Vol 267 (3) ◽  
pp. E422-E428 ◽  
Author(s):  
F. Lariviere ◽  
R. Moussalli ◽  
D. R. Garrel
Keyword(s):  
Menstrual Cycle ◽  
Energy Expenditure ◽  
Protein Metabolism ◽  
Luteal Phase ◽  
Resting Energy Expenditure ◽  
Follicular Phase ◽  
Co2 Production ◽  
Free Triiodothyronine ◽  
Leucine Oxidation

Possible changes in protein metabolism during the menstrual cycle were examined in eight healthy women who received an intravenous infusion of L-[1-13C]leucine on time during the follicular phase of the menstrual cycle and one time during the luteal phase. Enrichment of plasma [13C]ketoisocaproate and expired 13CO2 were measured to determine leucine flux and oxidation. Continuous respiratory gas exchange measurements were made for the determination of CO2 production, O2 uptake, and energy expenditure. The day of the tests, plasma thyroid hormone concentrations were measured as well as plasma and urinary cortisol. Leucine flux was higher during the luteal than during the follicular phase (2.25 +/- 0.39 vs 2.01 +/- 0.42 mumol.kg-1.min-1; P < 0.01), and leucine oxidation was also increased during the luteal phase [0.52 +/- 0.14 vs. 0.44 +/- 0.05 mumol.kg-1.min-1 (P < 0.05) for luteal and follicular phases, respectively]. Resting energy expenditure was increased during the luteal phase compared with the follicular phase (218 +/- 22 and 199 +/- 12 kJ/h, respectively). Plasma free triiodothyronine (T3) and the ratio triiodothyronine/reverse triiodothyronine (T3/rT3) were both significantly higher during the luteal phase [7.7 +/- 0.6 vs. 7.1 +/- 0.8 and 4.65 +/- 0.80 vs. 3.93 +/- 0.70 for T3 and T3/rT3, respectively (P < 0.05 for both comparisons)]. This study shows small changes in protein metabolism during the menstrual cycle in women, with an increase in oxidative leucine metabolism during the luteal phase. The concomitant increase observed in circulating free T3 raises the possibility that fluctuations in protein metabolism and thyroid hormones throughout the menstrual cycle are causally related.

Adolescent athletes and nutrition – analysis of two groups of children

2020 ◽  
pp. 1-6
Author(s):  
Tatyana Dzimbova
Keyword(s):  
Energy Expenditure ◽  
Energy Intake ◽  
Eating Habits ◽  
Energy Deficit ◽  
Young Athletes ◽  
Adolescent Athletes ◽  
Basketball Players ◽  
Calcium Magnesium ◽  
The Right

Introduction. Proper nutrition is crucial for child and adolescent athletes to maintain growth and development and to achieveoptimal results in sports. It is very important to balance the energy expenditure with the energy intake in order to prevent the energy deficit or excess.Materials and methods. Subjects involved in two different sports participated in the study: 13 gymnasts (age 13.8 ± 4.1 years, height 153.4 ± 11.3 cm, weight 47.1 ± 10.5 kg) and 15 basketball players (age 15.5 ± 1.1 years, height 176.7 ± 7.9 cm, weight 65.2 ± 10.7 kg). Determination of total energy expenditure was made by prediction equations. The subjects maintained a food records for 5 consecutive days, which were processed in the ASA24 system of the NCI. Results and discussion. Energy intake in both groups is sufficient to meet the daily needs, development of young athletes andprovide the energy needed in training. The intake of three minerals (calcium, magnesium and potassium) and three vitamins (D, E and A) was lower than recommended values in both groups.Conclusion. As a result of the busy schedule of adolescent athletes, their main meals are out of home, and the proportion of highly processed foods containing small amounts of important vitamins and minerals is high. The main recommendations include dairy products, fruits, vegetables and whole grains. The idea behind the changes is to give young athletes the right diet and the right eating habits.

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