In this study we assessed the impact of high-frequency whole body vibration with acceleration of 0,3 g on the structure of the femur in in conditions of obesity and limited mobility. It is known that mechanical loads stimulate bone remodeling by reducing the apoptosis of osteoblasts and osteocytes, increasing their proliferation and differentiation. Reducing the functional load inhibits osteogenesis and activates bone resorption. Aim. To study the effect of nonphysiological whole body vibration (acceleration 0,3 g) on bone remodeling and the condition of bone nanocomposite in conditions of obesity and limited mobility Materials and methods. The experimental study was performed on 54 male Wistar rats weighing 180-200 g in accordance with bioethical principles. Experimental rats were divided into 3 groups of 18 individuals: control – standard vivarium conditions, I experimental group – high-calorie diet and sedentary lifestyle, II experimental group – high-calorie diet and sedentary lifestyle + whole body vibration. Obesity model realized using high-calorie diet C 11024, (Research Diets, New Brunswick, NJ); and limited mobility – using cages with partitions that limit the mobility of rats. Vertical vibration oscillations were simulated using a vibrating table with a frequency of 50 Hz, 0,3 g. X-ray diffraction analysis of the prepared bone powder was used to characterize the crystalline organization of bone nanocomposites. The mineral mass of the femur was determined quantitatively by atomic adsorption analysis. Results. Using this experimental model, we proved that the mineral mass of the femur decreases from the 8th week. The decrease in the relative amount of crystalline phase lasted throughout the experiment, up to the 24th week of the study (p <0.05), and was not accompanied by violations of the nanostructure of the crystal lattice of hydroxyapatite. These structural changes were accompanied by a change in the quantitative indicators of calcium in the fragments of the femur. Obese and sedentary rats had lower bone mineral mass (p <0.05) compared to animals fed a normal diet and additionally affected by whole body vibration. Mechanical stimuli improved the structural and functional condition of the bones and prevented the accumulation of adipose tissue, as evidenced by changes in the weight of experimental rats. Conclusions. Whole body vibration with acceleration of 0,3 g, has a positive effect on body weight, has an antiresorptive effect, prevents bone loss during obesity, and did not destabilize the crystal lattice of the bone mineral composites at the end of the experiment. Therefore, exercises are an effective method to improve bone condition and should be used as an adjunct to pharmacological therapy for osteoporosis.
/ Added: 18.05.2020
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