The measurement of total body water in the sheep

1962 ◽  
Vol 13 (2) ◽  
pp. 335 ◽  
Author(s):  
AR Till ◽  
AM Downes
Keyword(s):  
Total Body Water ◽  
Specific Activity ◽  
Standard Procedure ◽  
Tritiated Water ◽  
Mean Value ◽  
Body Water ◽  
The Body ◽  
True Value ◽  
Two Samples ◽  
Total Body

After intravenous injections of tritiated water (TOH) were given to sheep, about 5 hr was required for the dose to equilibrate with the total body water (TBW). A standard procedure for estimating the TBW of sheep was adopted, in which blood samples were taken 6 and 7 hr after an intravenous injection of tritiated water. The specific activity of the water from the two samples was measured and the mean value used for the calculation of TBW. As a result of a study of the errors in this method, it was concluded that the value obtained for the TBW is about 2% of the body weight higher than the true value, and has an error of about ±3%. The estimate of the errors was based on direct measurements of the losses of TOH from the animal, and on measuring the rate of fall in specific activity of the TBW. This specific activity fell exponentially with time, with turnover half-times ranging from 3.5 to 16.3 days for sheep housed indoors.

Estimation of water content by tritium dilution of animals subjected to rapid live-weight changes

1969 ◽  
Vol 72 (1) ◽  
pp. 31-40 ◽  
Author(s):  
W. R. McManus ◽  
R. K. Prichard ◽  
Carolyn Baker ◽  
M. V. Petruchenia
Keyword(s):  
Body Weight ◽  
Water Content ◽  
Total Body Water ◽  
Compensatory Growth ◽  
Specific Activity ◽  
Tritiated Water ◽  
Body Water ◽  
Under Nutrition ◽  
The Mean ◽  
Total Body

SUMMARYThe use of tritiated water to estimate total body-water content of animals experiencing recovery from under-nutrition was studied.The time for equilibration of tritiated water (TOH), given intraperitoneally, with total body water (TBW) was determined in rabbits and in rats. As judged by the specific activity of blood water, equilibration had occurred by 76–125 min in the rabbit and did not appear to be affected by the plane of nutrition. However, between slaughter groups the specific activity of water obtained from the liver 180 min after injection of TOH was significantly different from the specific activity of water simultaneously obtained from the blood plasma. It is concluded that the liver is not a suitable tissue to use for testing achievement of equilibration.As judged by the specific activity of blood water compared to that of water from the whole body macerate, equilibration in mature rats either in stable body condition or undergoing rapid compensatory growth occurred in less than 60 min.A trial comparing TOH-space (corrected by 3% body weight) and actual TBW (by desiccation) was conducted on thirty rabbits which experienced under-nutrition followed by compensatory growth.Prior to under-nutrition the agreement between actual and estimated TBW was satisfactory and within 2·3%. During compensatory growth the agreement was poor— the TOH values over-estimating actual TBW by about 12%.A trial with mature rats confirmed the findings with rabbits. For rats in stable body weight the mean estimated TOH-space for fourteen animals was within 1·2% of the actual TBW. For fourteen rats undergoing compensatory growth the mean estimated TOH-space (corrected by 3% body weight) overestimated actual TBW by 6·2%.

Estimation of body water and fat in cattle using tritiated water space and live weight with particular reference to the influence of breed

1983 ◽  
Vol 101 (2) ◽  
pp. 257-264 ◽  
Author(s):  
P. R. N. Chigaru ◽  
D. H. Holness
Keyword(s):  
Body Fat ◽  
Total Body Water ◽  
Tritiated Water ◽  
Live Weight ◽  
Close Relation ◽  
Body Water ◽  
The Body ◽  
Metabolizable Energy ◽  
Complete Diet ◽  
Total Body

SUMMARYThe body composition of 18 each of Mashona, Afrikaner and Hereford heifers was measured at the beginning and after 16 and 32 weeks of the experiment. The heifers not slaughtered at the beginning of the experiment were fed a complete diet containing 132 g crude protein and 12·0 MJ metabolizable energy/kg dry matter. Before slaughter, the animals were deprived of food and water for 24 h. Each animal was infused with 1 mCi of tritiated water (TOH) in order to measure total body water (TBW) and to estimate body fat.The growth rate of the three breeds of heifers was similar despite differences in age and initial live weight. Both TBW and fat proportions, however, differed significantly (P < 0·01) between slaughter stages for each breed and between breeds at each slaughter stage. At the first, second and final slaughter stages the proportions of TBW were: 68·0, 59·4 and 54·5% for Mashona; 70·;5, 64·3 and 58·3% for Afrikaner and 65·3, 57·6 and 46·2% for Hereford heifers respectively. The corresponding proportions of body fat were: 10·2, 18·4 and 24·2% for Mashona; 6·6, 12·0 and 20·0% for Afrikaner and 13·7, 20·8 and 25·8% for Hereford heifers respectively.There was a close relation between empty body weight and live weight at slaughter which was not influenced by breed. Both TBW and fat were estimated more accurately when TOH space and live weight were used jointly. However, the slopes of the prediction equations for each breed were significantly different (P < 0·05) in the case of both total body water and fat. It was necessary to use separate equations for each breed in order to predict either body water or fat. The significance of these findings for the estimation of body fat in live cattle is discussed.

The effect of route of dosing and method of estimation of tritiated water space on the determination of total body water and the prediction of body fat in sheep

1974 ◽  
Vol 82 (1) ◽  
pp. 105-112 ◽  
Author(s):  
B. S. W. Smith ◽  
A. R. Sykes
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Total Body Water ◽  
Specific Activity ◽  
Tritiated Water ◽  
Multiple Correlation Coefficient ◽  
Body Water ◽  
Total Body ◽  
Water Space

SUMMARYEight mature female sheep were offered a ration which maintained body weight constant during a 20-week period. During the final 10 weeks a comparison was made in each animal of the pattern of equilibration and urinary losses of tritiated water during 8 h after dosing by four different routes. These were intravenous, intraperitoneal, intraruminal and a combination of the intraperitoneal and intraruminal routes. Tritiated water spaces were calculated from (a) the 8-h plasma specific activity and (b) by extrapolation to zero time of the plasma specific activities during the 7 days after injection. At the end of the experiment the fat and water contents of the bodies of the sheep were determined directly.Complete equilibration of tritiated water between plasma and rumen water was not achieved in all animals 8 h after intravenous or intraperitoneal injection but was when the rumen was primed by the combination of intraperitoneal and intraruminal dosing. After intraruminal dosing equilibration was not achieved in any animal within 8 h of dosing.Urinary losses of marker were lower after intraruminal dosing but otherwise averaged 4–5 % of the dose/1 urine. This was equivalent to 0·3–6·7% of the dose for individual sheep.Errors resulting from incomplete equilibration and urinary loss of marker did not influence the efficiency of prediction of total body water from tritiated water space. The multiple correlation coefficient relating body fat with empty body weight and its water content was very high (r = 0·99). Errors introduced into this relationship by the inclusion of gut water in the prediction equations were apparently of a similar magnitude to those resulting from the errors in the estimation of tritiated water space.The extrapolation method for the determination of tritiated water space was shown to have the same accuracy as equilibration techniques under these controlled dietary conditions.

Body composition in vivo. IX. The relation of body composition to the tritiated water spaces of ewes and wethers fasted for short periods

1968 ◽  
Vol 19 (2) ◽  
pp. 267 ◽  
Author(s):  
BA Panaretto
Keyword(s):  
Body Composition ◽  
Total Body Water ◽  
Tritiated Water ◽  
Body Water ◽  
The Body ◽  
Total Body ◽  
Water Space

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.

Body composition of live cattle and its prediction from fasted liveweight, tritiated water space and age

1982 ◽  
Vol 33 (2) ◽  
pp. 375 ◽  
Author(s):  
PR Bird ◽  
PC Flinn ◽  
JWD Cayley ◽  
MJ Watson
Keyword(s):  
Body Composition ◽  
Total Body Water ◽  
Tritiated Water ◽  
Protein A ◽  
Body Water ◽  
The Body ◽  
Linear Regression Models ◽  
Wide Range ◽  
Total Body ◽  
Water Space

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) =

scholarly journals The Use of Infrared Spectrophotometry for Measuring Body Water Spaces

1999 ◽  
Vol 45 (7) ◽  
pp. 1077-1081 ◽  
Author(s):  
Graham Jennings ◽  
Leslie Bluck ◽  
Antony Wright ◽  
Marinos Elia
Keyword(s):  
Sample Preparation ◽  
Total Body Water ◽  
Biological Fluids ◽  
Deuterium Oxide ◽  
Body Water ◽  
The Body ◽  
Infrared Spectrophotometry ◽  
Significant Difference ◽  
Total Body ◽  
Novel Algorithm

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.

scholarly journals The impact of total body water on breath alcohol calculations

2020 ◽  
Vol 132 (17-18) ◽  
pp. 535-541
Author(s):  
Gregor S. Reiter ◽  
Markus Boeckle ◽  
Christian Reiter ◽  
Monika H. Seltenhammer
Keyword(s):  
Total Body Water ◽  
Elimination Rate ◽  
Test Group ◽  
Body Water ◽  
The Body ◽  
Blood Alcohol ◽  
Individual Parameter ◽  
Breath Alcohol ◽  
Total Body ◽  
The Impact

Summary Due to a legislative amendment in Austria to determine breath alcohol (BrAC) instead of blood alcohol (BAC) in connection with traffic offences, many results of blood alcohol calculations were simply converted using distinct conversion factors. In Austria, the transformation of BAC to BrAC was carried out by using a factor of 1:2000, which, however, is commonly known to be too low. Noticing the great demand for a calculation method that is not exclusively based on blood alcohol, a formula for calculating breath alcohol based on blood alcohol was published in 1989, but in which the body surface area (BSA) was considered the most important influencing variable. In order to refine this new method, a liquor intake experiment was conducted combined with measurements of total body water (TBW) as an additional variable, using hand to foot bioelectrical impedance assessment (BIA). The test group comprised 37 men and 40 women to evaluate the accuracy of TBW and BSA as an individual parameter for alcohol concentration. The correlation coefficient of BrAC with TBW was constantly higher than with BSA (maximum = 0.921 at 1 h and 45 min after cessation of alcohol intake). These results are valid for both men and women as well as in a gender independent calculation. Hence, for an accurate back calculation of BrAC adjusted values of eliminations rates had to be found. This study describes mean elimination rates of BrAC for both men (0.065 ± 0.011 mg/L h−1) and women (0.074 ± 0.017 mg/L h−1). As previously shown women displayed a significantly higher elimination rate than men (p = 0.006).

Body composition in vivo. VII. Relation between red cell volume and total body water in ewes

1965 ◽  
Vol 16 (4) ◽  
pp. 661 ◽  
Author(s):  
BA Panaretto ◽  
DA Little
Keyword(s):  
Body Composition ◽  
Cell Volume ◽  
Total Body Water ◽  
Mean Value ◽  
Body Water ◽  
Red Cell ◽  
Red Cell Volume ◽  
Total Body ◽  
Body Parameters

The relationship between total body water and red cell volume was determined in a group of non-pregnant crossbred ewes, in an endeavour to obtain a method which did not necessitate the use of radioisotopes for determining body composition. Total body water could be predicted from red cell volume. The 95% confidence interval for a mean value for total body water, predicted from the red cell volume, was ±18.8% of the mean. All other relations which can be derived between the red cell volume and other body parameters depended on this relation. The calculation of body composition from measurements of the red cell volume is discussed.

Total body water and the exchangeable hydrogen. I. Theoretical calculation of nonaqueous exchangeable hydrogen in man

1977 ◽  
Vol 232 (1) ◽  
pp. R54-R59 ◽  
Author(s):  
J. M. Culebras ◽  
F. D. Moore
Keyword(s):  
Theoretical Calculation ◽  
Total Body Water ◽  
Body Water ◽  
The Body ◽  
Protein Conformations ◽  
Molecular Conformations ◽  
Exchangeable Hydrogen ◽  
Short Period ◽  
Total Body ◽  
Short Time

A theoretical calculation of the total nonaqueous exchangeable hydrogen in protein, carbohydrates, and fat in man has been made. It shows that of the total exchangeable hydrogen in the body 5.22% is located in biochemical components, soluble in body water, containing hydrogen that is exchangeable with the isotope. This value represents a maximum upward distortion of total body water measurements by isotope dilution, due to the maximum possible exchangeability in these molecular conformations. From comparative measurements reported in the literature it is clear that this maximum is not achieved during the short period of time during which tritium-dilution studies are performed. It is the authors' belief that the hard-to-exchange amide hydrogens described by Blout in the protein conformations account for this failure of the isotope to achieve complete exchange in the short time allowed.

Accuracy of the tritium water dilution method for determining water flux in reindeer (Rangifer tarandus)

1976 ◽  
Vol 54 (6) ◽  
pp. 857-862 ◽  
Author(s):  
R. D. Cameron ◽  
R. G. White ◽  
J. R. Luick
Keyword(s):  
Total Body Water ◽  
Crude Protein ◽  
Tritiated Water ◽  
Water Flux ◽  
Body Water ◽  
Water Volume ◽  
Dilution Method ◽  
Wide Range ◽  
Total Body ◽  
Water Dilution

The accuracy of the tritium water dilution method in estimating water flux was evaluated in reindeer under various conditions of temperature and diet. Two non-pregnant female reindeer were restrained in metabolism stalls, within controlled-environment chambers, at temperatures of + 10, −5, and −20 °C; varying amounts of a commercial pelleted ration (crude protein, 13%) or mixed lichens (crude protein, 3%) were offered, and water was provided ad libitum either as snow or in liquid form. Total body water volume and water turnover were estimated using tritiated water, and the daily outputs of feces and urine were measured for each of 12 different combinations of diet and temperature. Statistical analysis of the data showed that the tritium water dilution technique gives accurate determinations of total body water flux over a wide range of environmental and nutritional conditions.

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