[Basic Research on the Microstructure of Rat Bones in the High-Altitude Environment of Qinghai-Tibet Plateau].

Objective: To establish a hypobaric hypoxia rat model in a real high-altitude environment, to investigate the effects of the real high-altitude environment on rat bone mass and bone microstructure using multiple methods such as Micro CT, blood biochemistry, and pathology, and to explore the potential mechanisms involved. Methods: Sprague Dawley (SD) rats were transported to the Yushu Plateau Laboratory (at 4250 m above sea level) in Qinghai Province and kept there for 4, or 8, or 18 months. These groups were designated as H-4, H-8, and H-18, respectively. Upon completion of the high-altitude exposure, these animals were transported to the Molecular Imaging Laboratory, West China Hospital, Sichuan University (at 500 m above sea level) in Chengdu for relevant testing and comparison with the control animals raised in a low-altitude environment for the same durations (designated L-4, L-8, and L-18). The tests performed included blood biochemistry, Micro CT imaging, and pathological assessments such as ELISA, Western blot, and HE and TRAP staining. Results: Compared with that of the control group, the body mass of rats in the H-4 and H-18 groups decreased significantly (H-4 group vs. L-4 group: [513.75±35.10] g vs. [649.18±60.03] g, Conclusion: The impact of high-altitude environment on rat femurs is characterized primarily by a reduction in trabecular bone mass and damage to bone microstructure.