Objective: Magnetic resonance (MR) relaxometry has recently been introduced for noninvasive body composition analysis in awake mice. The purpose of the present study was to extend the method to rats and to introduce calibration procedures that render MR relaxometry fully quantitative.
Research Methods And Procedures: Proton T(2) MR relaxometry at 4.7 Tesla was used for body composition analyses in 700 awake mice and 400 rats of different strains and conditions. Relaxograms calculated from the signal decays observed with multi-spin-echo acquisition provided well-separated contributions of tissue water and fat. Analysis of fat composition was carried out in vivo using (13)C-MR spectroscopy. Evolution of body composition in rats was assessed during drug treatment.
Results: MR relaxometry for noninvasive body composition analysis in laboratory rodents was implemented on a standard MR scanner, and a throughput of >30 animals per hour was achieved. Excellent linearity and reproducibility with coefficients of variance as low as 2.5% and 1.7% were obtained in mice and rats, respectively. The lean mass-to-water ratio (mice, 1.35 +/- 0.03; rats, 1.39 +/- 0.04) and the proton density of fat (mice, 8.1 +/- 0.2; rats, 8.9 +/- 0.2 g/mol) were determined from cross-sectional data. Fat composition analysis by (13)C-MR spectroscopy corroborated these findings and yielded information on the average acyl chain length (16.3 +/- 1.6) and contributions of saturated (27 +/- 3%), monounsaturated (22 +/- 2%), and polyunsaturated (51 +/- 3%) fatty acids. Longitudinal assessments in rats treated with sibutramine and dexfenfluramine showed dose-related changes in body composition.
Discussion: T(2) MR relaxometry backed by solid calibration provides a powerful means for rapid quantitative body composition analysis in awake mice and rats that is suitable for serial investigations in pharmaceutical research.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1038/oby.2004.200 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Updates on Methods for Body Composition Analysis: Implications for Clinical Practice.
Curr Obes Rep
January 2025
Metabolism and Body Composition, Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.
Background: Recent technological advances have introduced novel methods for measuring body composition, each with unique benefits and limitations. The choice of method often depends on the trade-offs between accuracy, cost, participant burden, and the ability to measure specific body composition compartments.
Objective: To review the considerations of cost, accuracy, portability, and participant burden in reference and emerging body composition assessment methods, and to evaluate their clinical applicability.
Serum and urinary uromodulin concentration in children and young adults with chronic kidney disease.
Pediatr Nephrol
January 2025
Department of Paediatrics, University Medical Centre Maribor, Ljubljanska ulica 5, 2000, Maribor, Slovenia.
Background: Serum and urinary uromodulin are emerging as potential cardiovascular risk factors. The aim of our study was to determine uromodulin in both serum and urine to evaluate their potential as early cardiovascular risk markers and markers of kidney function in children and young adults.
Methods: This case-control study included 72 participants - 42 children and young adults with chronic kidney disease stages 1-2 and 30 healthy controls.
Growth Differentiation Factor-15 Is Associated With Congestion-Related Anorexia and Weight Loss in Advanced Heart Failure.
JACC Heart Fail
January 2025
Institute for Clinical and Experimental Medicine (IKEM), Prague, Czech Republic. Electronic address:
Background: Growth differentiation factor (GDF)-15 is a pleiotropic cytokine that is associated with appetite-suppressing effects and weight loss in patients with malignancy.
Objectives: This study aims to investigate the relationships between GDF-15 levels, anorexia, cachexia, and clinical outcomes in patients with advanced heart failure with reduced ejection fraction (HFrEF).
Methods: In this observational, retrospective analysis, a total of 344 patients with advanced HFrEF (age 58 ± 10 years, 85% male, 67% NYHA functional class III), underwent clinical and echocardiographic examination, body composition evaluation by skinfolds and dual-energy x-ray absorptiometry, circulating metabolite assessment, Minnesota Living with Heart Failure Questionnaire, and right heart catheterization.
Potential of flaxseed oil blends to modulate tissue fatty acid composition and determination of safety parameters in Wistar rats.
Lipids
January 2025
Centre for Innovation in Nutrition Health Disease, Interactive Research School for Health Affairs, Bharati Vidyapeeth (Deemed to be University), Pune, India.
Non-communicable diseases (NCD) are associated with inflammation and oxidative stress which is further associated with omega-6 (ω6) and omega-3 (ω3) fatty acid (FA) imbalance favoring ω6 FA. By improving ω3 FA consumption, this imbalance can be altered to control NCD. Previously we have reported blends of flaxseed oil (FSO, ω3 FA) with palm olein (PO) or coconut oil (CO) were thermo-oxidatively stable with good storage stability and could improve ω6:ω3 ratio in cell lines.
View Article and Find Full Text PDFPosttraumatic Stress Disorder and Weight Loss in Male and Female Active-duty Service Members: A Weight Management Study.
Mil Med
January 2025
Mental Health Care Line, VA San Diego Healthcare System, San Diego, CA 92161, USA.
Background: Overweight and obesity are critical public health concerns with relevance to U.S. military personnel, as active duty service members must meet physical fitness and body composition standards.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!