Tuncay O C, Ho D, Barker M K
University of Mississippi Medical Center, Department of Orthodontics, Jackson.
Am J Orthod Dentofacial Orthop. 1994 May;105(5):457-63. doi: 10.1016/S0889-5406(94)70006-0.
Abrupt changes in oxygen availability within the periodontium have been suggested to have a regulatory role in alveolar bone remodeling during tooth movement; arguably, similar to that seen in bone growth or fracture healing. The purpose of this investigation was therefore to study the effects of ambient hypoxia and hyperoxia on osteoblast function in vitro. Osteoblast-enriched cultures from fetal rat calvariae were exposed to atmospheres of hyperoxia (90% O2) and hypoxia (10% O2) and assayed for media pH, pO2, pCO2, cellular proliferation, alkaline phosphatase (AP) activity, and collagen synthesis. Results of this study show that in low ambient oxygen tension cellular proliferation increases, whereas the AP activity, collagen synthesis, media pO2, PCO2 decreases. In contrast, in hyperoxic conditions cellular proliferation is suppressed with concomitant increases in: AP activity, collagen synthesis, and partial pressures for oxygen and carbon dioxide. Media pH remained unaffected. In crossover experiments, where cells were initially grown in hypoxic conditions and were switched to hyperoxic conditions, their metabolic activities were abruptly reversed. These findings in conjunction with earlier reports, suggest a triggering role for oxygen tension (an environmental factor) in bone remodeling.
牙周组织内氧气供应的突然变化被认为在牙齿移动过程中对牙槽骨重塑具有调节作用；可以说，类似于在骨骼生长或骨折愈合中所见到的情况。因此，本研究的目的是在体外研究环境性低氧和高氧对成骨细胞功能的影响。将来自胎鼠颅骨的富含成骨细胞的培养物暴露于高氧（90% O₂）和低氧（10% O₂）环境中，并检测培养基的pH值、pO₂、pCO₂、细胞增殖、碱性磷酸酶（AP）活性和胶原蛋白合成。本研究结果表明，在低环境氧张力下细胞增殖增加，而AP活性、胶原蛋白合成、培养基pO₂、PCO₂降低。相反，在高氧条件下细胞增殖受到抑制，同时AP活性、胶原蛋白合成以及氧气和二氧化碳的分压增加。培养基pH值保持不变。在交叉实验中，细胞最初在低氧条件下生长，然后切换到高氧条件，其代谢活性会突然逆转。这些发现与早期报告一起，表明氧张力（一种环境因素）在骨重塑中具有触发作用。
