Abstract: This work provides a comprehensive investigation of local (structural-functional) and systemic (metabolic) adaptive alterations in bone tissue, induced by hindlimb unloading of different durations in male Wistar rats. Hindlimb bone and blood samples were obtained from animals following 7- and 21-day hindlimb unloading, as well as from corresponding vivarium control groups. In the femur, the mass fractions of Ca, Mg, P, and Zn were measured using inductively coupled plasma atomic emission spectrometry. The trabecular compartment of the tibia was analyzed histomorphometrically. Serum concentrations of bone metabolism regulators—1,25-dihydroxyvitamin D3, parathyroid hormone (PTH), fibroblast growth factor-23 (FGF23), Dickkopf-related protein 1 (DKK1), sclerostin (SOST), osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL)—were determined using ELISA and multiplexed fluorescent bead-based immunoassay. It was found that the bones of animals after hindlimb unloading of both durations differed from the control groups by their lower mass and reduced Ca and Mg content. Low Zn values were noted after 21 days of exposure. The proportion of trabecular bone substance in the tibia and the parameters of osteocyte viability in animals after both durations of hindlimb unloading were significantly lower than in the control groups. Differences in serum levels of RANKL (after 7-day exposure) and OPG, DKK1 (after 21-day exposure) were found between the groups after hindlimb unloading and the corresponding control groups. Thus, antiorthostatic suspension led to local demineralization and structural alterations in rat bone tissue. Structural-functional changes were observed as early as 7 days of exposure, accompanied by a decrease in serum RANKL levels. After 21 days, changes in trabecular width, a decrease in blood OPG levels, a decrease in osteocyte number, and an increase in the proportion of empty lacunae after hindlimb unloading were noted against the background of low blood DKK1 content.

Cite: Lukicheva N.A. , Gordienko K.V. , Korotkova N.A. , Doronina M.S. , Baranovskaya V.B. , Vassilieva G.Y.
Comprehensive Analysis of Rat Bone Tissue after 7 and 21 Days of Hindlimb Unloading
Journal of Evolutionary Biochemistry and Physiology. 2026. V.62. N3. P.583-595. DOI: 10.1134/s0022093026030014 OpenAlex

Original: Лукичёва Н.А. , Гордиенко К.В. , Короткова Н.А. , Доронина М.С. , Барановская В.Б. , Васильева Г.Ю.
Комплексный анализ костной ткани крыс после 7‑ и 21‑суточной опорной разгрузки
Российский физиологический журнал им. И.М. Сеченова. 2026. Т.112. №6. С.1557–1580. DOI: 10.7868/s2658655X26060097

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W7165486984

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