Measurement of /sup 2/H/sub 2/O by IR absorbance in doubly labeled H/sub 2/O studies of energy expenditure
The energy expenditure of animals in their natural surroundings can be determined by measuring the turnover in body water of isotopes of oxygen and hydrogen. We evaluated the use of infrared spectrophotometry for measuring /sup 2/H/sub 2/O in small (20-microliters) water samples also labeled with 18O. For /sup 2/H/sub 2/O over the enrichment range of 0.1-1 atom%, there was a linear relationship between infrared absorbance and /sup 2/H/sub 2/O enrichment. /sup 2/H/sub 2/O enrichments could be measured with a precision and accuracy of less than or equal to 1%, using this relationship. The presence of /sup 18/O in water samples in enrichments of up to 1 atom% had no significant effect on measurement of /sup 2/H/sub 2/O by infrared absorbance. We measured the simultaneous turnover rates of /sup 2/H/sub 2/O and /sup 3/H in mice and turtles also labeled with 18O. Our results validated the use of infrared absorbance in doubly labeled water measures of energy expenditure and indicated that the fractionation factors in vivo for /sup 2/H/sub 2/O and /sup 3/H do not differ.
- Research Organization:
- Univ. of Wisconsin, Madison (USA)
- OSTI ID:
- 6902005
- Journal Information:
- Am. J. Physiol.; (United States), Vol. 255
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BODY FLUIDS
INFRARED SPECTRA
METABOLISM
MEASURING METHODS
ACCURACY
ALGORITHMS
DEUTERIUM
DOUBLE LABELLING
MICE
OXYGEN 18
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TURTLES
WATER
ANIMALS
BIOLOGICAL MATERIALS
EVEN-EVEN NUCLEI
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LABELLING
LIGHT NUCLEI
MAMMALS
MATERIALS
MATHEMATICAL LOGIC
NUCLEI
ODD-ODD NUCLEI
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
REPTILES
RODENTS
SPECTRA
STABLE ISOTOPES
VERTEBRATES
550501* - Metabolism- Tracer Techniques