An evaluation of the tritiated water method for estimating body water in small rodents

1975 ◽  
Vol 53 (9) ◽  
pp. 1376-1378 ◽  
Author(s):  
D. F. Holleman ◽  
R. A. Dieterich

The total body water of 27 rodents (live weights less than 100 g) were estimated by a tritiated water method and by direct analysis. There was no significant difference between the values as estimated by the two methods. The 95% confidence interval for total body water as estimated by the tritiated water method was ±10% of the value estimated from direct analysis. The accuracy of the method is acceptable for most applications, however, investigators should be cognizant of the estimate error, especially when calculating other components of body composition from total body water, e.g. body fat.

1963 ◽  
Vol 14 (6) ◽  
pp. 926 ◽  
Author(s):  
BA Panaretto ◽  
AR Till

The antipyrine, tritiated water, and N-acetyl-4-aminoantipyrine spaces were determined simultaneously in goats which had been deprived of feed and water for 48 hr. The animals were then killed, minced, and analysed for water, fat, protein, and ash contents. The compositions of the whole and empty bodies of the goats were calculated, and the relationships between the bodily components were compared with those reported for cattle, sheep, and some monogastric species. The relationships found between the components of the whole bodies compared favourably with those derived from the empty bodies. The relationships of the spaces determined in vivo to total body water, fat, and protein were found, and confidence statements were placed on predicted estimates.


1988 ◽  
Vol 59 (1) ◽  
pp. 109-124 ◽  
Author(s):  
R. J. Johnson ◽  
D. J. Farrell

1. Birds (n169) which varied in age, live weight, nutritional history, physiological state and genotype were slaughtered and analysed for total body water. Before slaughter, birds were injected with the water isotopes tritiated water (TOH) or deuterium oxide (D2O), or both, to determine TOH space or D2O space, or both, as estimates of total body water in vivo.2. At the mean total body water of all birds determined by desiccation, of 1096·4 (SD 424·1) g, TOH space and D2O space overestimated total body water by 10·4 and 8·5 % respectively. The difference between the isotopes was significant (P< 0·05).3. Based on recovery of isotope it was postulated that the main reason for the observed overestimation of total body water in vivo was incomplete recovery of isotope due to the vacuum sublimation technique. The mean recovery (%) of added isotope to whole blood after vacuum sublimation was 93·0 (SD 2·6) and 92·4 (SD 5·5) of the theoretical concentrations of TOH and D2O respectively.4. Nevertheless, accurate prediction of total body water was obtained from regression equations which included live weight and isotope-dilution space. Values required logarithmic (base 10) transformation before derivation of linear and multiple linear regression equations, and the precision of prediction was determined by the residual standard deviation (RSD).5. Total body water could be predicted with nearly equal accuracy from live weight or isotope-dilution space (RSD 0·025 and 0·020 respectively). Prediction of carcass protein was more accurate from live weight (RSD 0·033) than from TOH space (RSD 0·036), and inclusion of both variables resulted in only a marginal decrease in RSD to 0·031.6. The prediction of carcass fat and energy was markedly improved by the inclusion of isotope-dilution space in conjunction with live weight compared with live weight alone.7. The relations show the developmental nature of body composition of domestic fowl given diets adequate in nutrients. The prediction equations demonstrate the precision possible for studies in which estimates of body composition in poultry are required without slaughter.


1968 ◽  
Vol 19 (2) ◽  
pp. 267 ◽  
Author(s):  
BA Panaretto

Correlations are described between tritiated water space, total body water, fat, and protein in sheep subjected to 18–21 hr of fasting. These provide a system for estimating the body composition of living ruminants.


1984 ◽  
Vol 56 (6) ◽  
pp. 1647-1649 ◽  
Author(s):  
J. E. Schutte ◽  
E. J. Townsend ◽  
J. Hugg ◽  
R. F. Shoup ◽  
R. M. Malina ◽  
...  

Previous studies have reported that Blacks have 10–20% more bone mineral than Whites of the same height. Theoretically, this should mean that the lean body mass of Blacks is denser than that of Whites, such that formulas for calculating lean body mass from density in Whites will overestimate the lean body mass (and thus underestimate fatness) in Blacks. To determine if the lean body mass of Blacks is indeed denser than that of Whites, we measured density, total body water, and anthropometric dimensions in 19 white and 15 black male college students. The black and white cohorts were nearly identical in height, weight, and total body water. Among the Whites there was no significant difference between the observed density and that predicted from anthropometry, nor were there any significant differences between the dimensions of body composition calculated from total body water and from observed density. Among the Blacks, however, the observed density was significantly greater than that predicted from anthropometry, and the lean body mass calculated from observed density was significantly greater than that calculated from total body water. These results are consistent with the hypothesis that the lean body mass of the Blacks is denser than that of the Whites. Separate formulas should therefore be used for converting density to body composition. Based on our data, the correct formula for Blacks is: %fat = 100 X [(4.374/density) - 3.928]. This formula indicates a lean body density of 1.113 g/cm3 in Blacks compared with 1.100 in Whites.


1995 ◽  
Vol 268 (1) ◽  
pp. E153-E158 ◽  
Author(s):  
P. M. Catalano ◽  
W. W. Wong ◽  
N. M. Drago ◽  
S. B. Amini

Twenty women underwent body density (DB) measurements using underwater weighing with correction of residual lung volume by nitrogen dilution and total body water (TBW) using isotope dilution of 18O to estimate body composition at 30 wk of gestation. DB and TBW were used as independent variables in the same equation. The hydration constant (HC) of fat-free mass (FFM) was estimated as 0.762; based on this HC, new body composition equations for both DB and TBW were derived. These equations were prospectively tested in an additional 20 women at 30 wk of gestation. No significant differences were detected between estimates of percent body fat (%F) using either the newly derived DB or TBW equations and estimates of %F using both DB and TBW. Ten of these forty women were evaluated postpartum. There was no significant difference in %F estimated by either TBW or DB compared with standard equations (hydration of FFM = 0.72) and %F using both DB and TBW. These results highlight the importance of either measuring both DB and TBW or using an appropriate hydration constant for FFM in estimating body composition during pregnancy or conditions associated with increased body water.


1982 ◽  
Vol 33 (2) ◽  
pp. 375 ◽  
Author(s):  
PR Bird ◽  
PC Flinn ◽  
JWD Cayley ◽  
MJ Watson

The body composition of 23 Hereford steers was related to their liveweight after a 24 h fast (W), total body water (TBW), tritiated water space (T) and age in months (A) by using allometric or linear regression models. Fifteen steers, of similar initial age, were taken at intervals from a grazing experiment having a wide range of stocking rates. These steers were 15-22 months of age and 189-461 kg W at slaughter. Six younger and two older steers were also used to expand the range to 3-33 months and 90-517 kg. The steers were taken from pasture 3 h after sunrise and deprived of feed and water thereafter. After 4 h, tritiated water was given intramuscularly and 20 h later blood was collected and the animals were weighed and slaughtered. Models having the least residual standard deviation (r.s.d.) and the predictors which contributed significantly in the stepwise regression analysis (P i 0.05) are given for each range of W. T greatly improved the estimation of fat and slightly improved the prediction of protein. A only slightly improved the prediction of TBW and fat. Equations applicable to the narrow range of W were: total body water (kg) =


1993 ◽  
Vol 75 (4) ◽  
pp. 1776-1780 ◽  
Author(s):  
M. I. Goran ◽  
M. C. Kaskoun ◽  
W. H. Carpenter ◽  
E. T. Poehlman ◽  
E. Ravussin ◽  
...  

It is currently unclear whether age-specific equations should be used for assessing body composition from bioelectrical resistance. Kushner et al. (Am. J. Clin. Nutr. 56: 835#x2013;839, 1992) showed that the relationship between height2/resistance and total body water (TBW) is robust across a wide age range, although uncertainty remained over the relationship in preschool children. We therefore cross-validated the Kushner equation for predicting total body water in 4- to 6-yr-old children in two independent laboratories. TBW was measured from H2 18O dilution, and bioelectrical resistance and reactance were measured using an RJL 101A analyzer in 31 children (15 females, 16 males; 5 +/- 0.8 yr) studied in Burlington, Vermont, and 30 children (14 females, 16 males; 5 +/- 0.2 yr) studied in Phoenix, Arizona. There was no significant difference between TBW predicted from the Kushner equation and that measured in children in Burlington (11.76 +/- 2.00 vs. 11.91 +/- 2.46 kg; r = 0.94) or in Phoenix (11.53 +/- 1.64 vs. 11.66 +/- 1.90 kg; r = 0.94). The Kushner equation for TBW can be transformed into an equation for fat-free mass (FFM) by using published age- and gender-specific constants for the hydration of FFM: hydration of FFM = 76.9 - 0.25 age (yr) - 1.9 gender where female equals 0 and male equals 1. The intraclass reliability for estimates of fat mass and FFM with the use of bioelectrical resistance in an independent group of 26 children (5.0 +/- 0.8 yr, 20.2 +/- 3.0 kg) was > 0.99 for duplicate observations performed 2 wk apart.(ABSTRACT TRUNCATED AT 250 WORDS)


1980 ◽  
Vol 28 (3) ◽  
pp. 395 ◽  
Author(s):  
HR Bakker ◽  
AR Main

In order to compare the welfare of different populations of the quokka on Rottnest I., the tammar Macropus eugenii on Garden I., and the hare-wallaby Lagorchestes conspicillatus on Barrow I., a condition index is developed, based on the relationship between body weight and leg length (from the bottom of the lateral calcaneal ridge of the calcaneum to the tibia1 tuberosity at the top of the tibia). Its validity was tested by determining body composition of 12 quokkas. There is a high correlation between the values predicted for sheep and those found in the quokka, but the quokka tends to have less fat and protein for a given weight and total body water content (TBW). In the quokka, tammar and hare-wallaby, there is a significant negative correlation between the condition index and corrected total body water content. The condition index of field animals of all three species is given. A significant difference was found between the condition of quokkas on Rottnest in April 1976 and April 1977. No significant differences existed between the hare-wallaby samples, either between locations or between seasons. The general application of the condition index is discussed.


PEDIATRICS ◽  
1962 ◽  
Vol 29 (6) ◽  
pp. 883-889
Author(s):  
Wesley M. Clapp ◽  
L. Joseph Butterfield ◽  
Donough O'Brien

Normal values for both total body water and extracellular water have been determined in 86 premature infants aged 1 to 90 days and weighing 940 to 2,435 gm, with use of the techniques of deuterium oxide and bromide dilution. Nine full-term infants aged 1 to 6 days and weighing 2,590 to 4,985 gm were similarly studied. Nine infants with the respiratory distress syndrome and eight infants of toxemic mothers studied in the first 24 hours of life showed no significant difference in their body water compartments in comparison to a control group of normal infants matched for age and weight. Seven infants of diabetic mothers studied in the first 24 hours of life showed a significant decrease in total body water, expressed as percentage of body weight, with a normal intracellular to extracellular water ratio. These data indirectly support other evidence that there is an increase in body fat in these infants at birth. See Table in the PDF file


1999 ◽  
Vol 45 (7) ◽  
pp. 1077-1081 ◽  
Author(s):  
Graham Jennings ◽  
Leslie Bluck ◽  
Antony Wright ◽  
Marinos Elia

Abstract Background: The conventional method of measuring total body water by the deuterium isotope dilution method uses gas isotope ratio mass spectrometry (IRMS), which is both expensive and time-consuming. We investigated an alternative method, using Fourier transform infrared spectrophotometry (FTIR), which uses less expensive instrumentation and requires little sample preparation. Method: Total body water measurements in human subjects were made by obtaining plasma, saliva, and urine samples before and after oral dosing with 1.5 mol of deuterium oxide. The enrichments of the body fluids were determined from the FTIR spectra in the range 1800–2800 cm−1, using a novel algorithm for estimation of instrumental response, and by IRMS for comparison. Results: The CV (n = 5) for repeat determinations of deuterium oxide in biological fluids and calibrator solutions (400–1000 μmol/mol) was found to be in the range 0.1–0.9%. The use of the novel algorithm instead of the integration routines supplied with the instrument gave at least a threefold increase in precision, and there was no significant difference between the results obtained with FTIR and those obtained with IRMS. Conclusion: This improved infrared method for measuring deuterium enrichment in plasma and saliva requires no sample preparation, is rapid, and has potential value to the clinician.


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