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Quantification of body fluid compartmentalization by combined time-domain nuclear magnetic resonance and bioimpedance spectroscopy. Am J Physiol Regul Integr Comp Physiol 2021 01 01;320(1):R44-R54



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Pubmed Central ID




Scopus ID

2-s2.0-85099721279   3 Citations


The measurement of fluid compartmentalization, or the distribution of fluid volume between extracellular (ECF) and intracellular (ICF) spaces, historically requires complicated, burdensome, and often terminal methodologies that do not permit repeated or longitudinal experiments. New technologies including time-domain nuclear magnetic resonance (TD-NMR)-based methods allow for highly accurate measurements of total body water (TBW) within minutes in a noninvasive manner, but do not permit dissection of ECF versus ICF reservoirs. In contrast, methods such as bioimpedance spectroscopy (BIS) allow dissection of ECF versus ICF reservoirs but are hampered by dependence on many nuanced details in data collection that undermine confidence in experimental results. Here, we present a novel combinatorial use of these two technologies (NMR/BIS) to improve the accuracy of BIS-based assessments of ECF and ICF, while maintaining the advantages of these minimally invasive methods. Briefly, mice undergo TD-NMR and BIS-based measures, and then fat masses as derived by TD-NMR are used to correct BIS outputs. Mice of the C57BL/6J background were studied using NMR/BIS methods to assess the effects of acute furosemide injection and diet-induced obesity on fluid compartmentalization, and to examine the influence of sex, body mass and composition, and diet on TBW, ECF, and ICF. We discovered that in mice, sex and body size/composition have substantial and interactive effects on fluid compartmentalization. We propose that the combinatorial use of NMR/BIS methods will enable a revisioning of the types of longitudinal, kinetic studies that can be performed to understand the impact of various interventions on body fluid homeostasis.

Author List

Segar JL, Balapattabi K, Reho JJ, Grobe CC, Burnett CML, Grobe JL


Justin L. Grobe PhD Associate Professor in the Physiology department at Medical College of Wisconsin
John J. Reho Research Scientist II in the Physiology department at Medical College of Wisconsin
Jeffrey L. Segar MD Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Body Composition
Body Fluid Compartments
Body Size
Electric Impedance
Fluid Shifts
Magnetic Resonance Spectroscopy
Mice, Inbred C57BL
Reproducibility of Results
Sex Factors