Measurement of total body water content in horses, using deuterium oxide dilution.
Abstract: To measure total body water (TBW) content in horses, using deuterium oxide (D2O) dilution. Methods: Six 8- to 10-year-old healthy untrained mixed-breed horses, weighing (mean +/-SD) 503.4 +/- 64.0 kg. Methods: After a 12-hour nonfeeding period, 6 horses were given D2O (0.14 g/kg of body weight) via nasogastric tube. Blood samples were collected from a preplaced indwelling jugular vein catheter prior to and 1 to 8, 10, 12, 14, and 24 hours after administration of D2O. Blood samples were centrifuged immediately, and plasma was collected and stored at -70 C until analysis. The D2O content in plasma was measured by zinc reduction to deuterium gas. The resulting gas was measured, using an isotope ratio mass spectrometer. Results: Deuterium oxide was rapidly absorbed from the gastrointestinal tract of all horses, and reached peak (mean +/- SD) plasma concentration (1,454.4 +/- 163 delta D/ml or parts/thousand) 1 hour after administration. Plasma concentration decreased slowly during the next 2 to 3 hours, then remained statistically constant from 2 to 5 hours (early plateau phase) and 3 to 7 hours (late plateau phase) after administration. Mean +/- SEM TBW content was 623.0 +/- 2.2 ml/kg (62.3% of body weight) for the early plateau phase and 630.3 +/- 2.2 ml/kg (63.0% of body weight) for the late plateau phase. Conclusions: Deuterium oxide dilution appears to be of value for measurement of TBW content in horses, and has a 4-hour plateau effect. Equilibration of D2O with large intestinal water may be the reason for the prolonged equilibrium time and plateau effect seen in these horses. Conclusions: Deuterium oxide appears safe and efficacious for determining TBW content in horses and may be helpful for determining changes in TBW content during exercise and disease.
Publication Date: 1997-11-05 PubMed ID: 9328654
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- Journal Article
Summary
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The research article discusses a study aimed at measuring total body water content in horses by utilizing a technique known as deuterium oxide dilution.
Study Design and Experimental Procedure
- The study was conducted on six healthy, untrained mixed-breed horses aged between 8 to 10 years, averaging around 503.4 kilograms.
- The horses were first submitted to a 12-hour fasting period before deuterium oxide (or heavy water) was introduced into their bodies via a nasogastric tube at a dose of 0.14 grams per kilogram of body mass.
- Blood samples were collected at several time intervals (pre-administration and 1 to 24 hours post-administration) using an indwelling jugular vein catheter.
- The samples were immediately centrifuged, leading to the collection of plasma that was stored at -70°C for later analysis.
- The deuterium oxide content in the plasma was determined through a process involving zinc reduction to deuterium gas. The deuterium gas generated was then measured with an isotope ratio mass spectrometer, a tool designed to analyze the composition of isotopes within a sample.
Results
- The deuterium oxide was quickly taken up by the horse’s gastrointestinal tract, reaching its highest plasma concentration one hour after administration.
- The plasma concentration then experienced a slow dip over the next two to three hours, after which it maintained a relatively constant level ranging from two to five hours (the early plateau phase) and three to seven hours (the late plateau phase) post-administration.
- The total body water content was determined to be 62.3% of body weight in the early plateau phase and 63.0% of body weight in the late plateau phase.
Conclusions
- The use of deuterium oxide dilution was found to be a valuable way of assessing total body water content in horses. The method demonstrated a four-hour plateau effect, which might be due to the equilibration of the deuterium oxide with water in the horse’s large intestine.
- The technique was deemed safe and effective not only for determining a horse’s total body water content, but also has the potential of being used to track changes in this metric during instances of exercise or disease.
Cite This Article
APA
Andrews FM, Nadeau JA, Saabye L, Saxton AM.
(1997).
Measurement of total body water content in horses, using deuterium oxide dilution.
Am J Vet Res, 58(10), 1060-1064.
Publication
Researcher Affiliations
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville 37901-1071, USA.
MeSH Terms
- Animals
- Body Composition / physiology
- Body Water
- Body Weight / physiology
- Deuterium Oxide / analysis
- Deuterium Oxide / blood
- Female
- Horses / blood
- Horses / physiology
- Male
- Radioisotope Dilution Technique / veterinary
- Reference Values
- Regression Analysis
- Time Factors
- Zinc
Citations
This article has been cited 2 times.- Greco-Otto P, Léguillette R. Assessment of body fluids and blood parameters associated with rapid weight change in heavy horses. Can Vet J 2019 Jul;60(7):721-724.
- Riek A, Gerken M. Estimating total body water content in suckling and lactating llamas (Lama glama) by isotope dilution. Trop Anim Health Prod 2010 Aug;42(6):1189-93.
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