A noninvasive method to study the evolution of extracellular fluid volume in mice using time-domain nuclear magnetic resonance.
Am J Physiol Renal Physiol
; 319(1): F115-F124, 2020 07 01.
Article
em En
| MEDLINE
| ID: mdl-32475134
ABSTRACT
Maintaining water homeostasis is fundamental for cellular function. Many diseases and drugs affect water balance and plasma osmolality. Water homeostasis studies in small animals require the use of invasive or terminal methods that make intracellular fluid volume and extracellular fluid volume (ECF) monitoring over time stressful and time consuming. We examined the feasibility of monitoring mouse ECF by a noninvasive method using time-domain nuclear magnetic resonance (TD-NMR). This technique allows differentiation of protons in a liquid environment (free fluid) from protons in soft tissues containing a majority of either small molecules (lean) or large molecules (fat). Moreover, this apparatus enables rapid, noninvasive, and repeated measurements on the same animal. We assessed the feasibility of coupling TD-NMR analysis to a longitudinal metabolic cage study by monitoring mice daily. We determined the effect of 24-h water deprivation on mouse body parameters and detected a sequential and overlapping decrease in free fluid and lean mass during water deprivation. Finally, we studied the effect of mineralocorticoids that are known to induce a transient increase in ECF but for which no direct measurements have been performed in mice. We showed, for the first time, that mineralocorticoids induced a transient ~15% increase in free fluid in conscious mice. TD-NMR is, therefore, the first method to allow direct measurement of discrete changes in ECF in conscious small animals. This method allows analysis of kinetic changes to stimuli before investigating with terminal methods and will allow further understanding of fluid disorders.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Espectroscopia de Ressonância Magnética
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Desidratação
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Líquido Extracelular
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol Renal Physiol
Assunto da revista:
FISIOLOGIA
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NEFROLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
França