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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adipocytes, Alkaline Phosphatase, Animals, Apoptosis, Bone Density Conservation Agents, Cell Differentiation, Cell Proliferation, Cells, Cultured, Cytoprotection, Dose-Response Relationship, Drug, Estrogens, Etidronic Acid, Female, Gene Expression, Humans, Mesenchymal Stem Cells, Osteoblasts, Osteoclasts, Osteocytes, Osteoporosis, Postmenopausal, Ovariectomy, Rats, Rats, Sprague-Dawley, Risedronic Acid.
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Does low-dose risedronate sodium protect bone cells after abrupt oestrogen withdrawal? Context: To investigate the effects of low-dose risedronate sodium on the in vitro cellular profile of osteoblasts, adipocytes, osteocytes and osteoclasts in a rat model of abrupt oestrogen deficiency. Oestrogen deficiency was induced by ovariectomy in 24 female rats.  The rats were treated with low-dose (0.24 μg/kg) or high-dose (2.4 μg/kg) risedronate sodium for 4 days presurgery, continuing every 3 days until 15 days postsurgery. Osteogenic and adipogenic differentiation were determined in cultured bone marrow cells by alkaline phosphatase and Oil  Red O staining, respectively, and by osteogenic and adipogenic gene expression. Osteoclast formation was measured in bone marrow cells stimulated with macrophage colony-stimulating factor and receptor activator of nuclear factor κB ligand, and stained with tartrate-resistant acid phosphatase.  Osteocyte apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling assay and B-cell lymphoma-2 (Bcl-2) immunohistochemistry. Low-dose risedronate sodium enhanced osteoblast differentiation, suppressed adipocyte differentiation  and osteoclast formation, and reduced osteocyte apoptosis through regulation of Bcl-2 and Bcl-2-associated X protein.
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Low-dose risedronate sodium may have clinical benefit in protecting against bone loss after abrupt oestrogen deficiency. Final Decision: yes