In vivo animal models of body composition in aging

• Published in: The Journal of nutrition Vol. 123; no. 2; pp. 459 - 464
• Main Authors: Yasumura, S. (State University of New York, Brooklyn.), Jones, K, Spanne, P, Schidlovsky, G, Wielopolski, L, Ren, X, Glaros, D, Xatzikonstantinou, Y
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Bethesda, MD American Society for Nutritional Sciences 01.02.1993; American Institute of Nutrition
• Subjects: Aging & longevity; Aging - physiology; ANALISIS POR ACTIVACION NEUTRONICA; ANALYSE PAR ACTIVATION NEUTRONIQUE; Anatomy & physiology; Animals; AZOTE; Biological and medical sciences; Body Composition - physiology; Bones; CALCIO; CALCIUM; CHLORURE; CLORUROS; CONTENIDO DE CENIZA; DENSIDAD; DENSITE; ENVEJECIMIENTO; EVALUACION; EVALUATION; FORMACION OSEA; FORMATION DES OS; Fundamental and applied biological sciences. Psychology; General aspects. Body compartment; HUESOS; Humans; Metabolisms and neurohumoral controls; MODELE ANIMAL; MODELOS ANIMALES; Models, Biological; Neutron Activation Analysis; NITROGENO; NUTRICION HUMANA; NUTRITION HUMAINE; RADIOGRAFIA; RADIOGRAPHIE; Rats; RAYON X; RAYOS-X; Rodents; SODIO; SODIUM; TECHNIQUE ANALYTIQUE; TECNICAS ANALITICAS; TENEUR EN CENDRES; Tomography, X-Ray Computed; Vertebrates: anatomy and physiology, studies on body, several organs or systems; VIEILLISSEMENT; Congress; Animal model; Neutron activation analysis; Senescence; Adipose tissue; Rat; Photon activation; Rodentia; Review; Inorganic element; Body composition; Proteins; In vivo; Vertebrata; Mammalia; Tomography; X ray fluorescence spectrometry; Chemical composition; Skeleton; Morphometry; Age
• ISSN: 0022-3166; 1541-6100
• DOI: 10.1093/jn/123.suppl_2.459

We developed several techniques that provide data on body elemental composition from in vivo measurements in rats. These methods include total body potassium by whole-body counting of endogenous 40K; total body calcium (TBCa), sodium and chloride by in vivo neutron activation analysis and total body phosphorus (TBP) and nitrogen (TBN) by photon activation analysis. These elements provide information on total body fat, total body protein and skeletal mass. Measurements were made in 6-, 12- and 24-month-old rats. TBN increased slightly between 6 and 12 months but was significantly lower by 24 months, indicating a substantial loss in total body protein. Working at the National Synchrotron Light Source, we studied rat femurs by computed microtomography (CMT), and the elemental profile of the femur cortex by synchrotron-radiation induced X-ray emission (SRIXE). Although there were no significant changes in TBCa and TBP, indices of skeletal mass, CMT revealed a marked increase in the size and number of cavities in the endosteal region of the femur cortex with increasing age. The SRIXE analysis of this cortical bone revealed a parallel decrease in the endosteal Ca/P ratio. Thus, there are major alterations in bone morphology and regional elemental composition despite only modest changes in total skeletal mass