Modifying oxygen tension affects bone marrow stromal cell osteogenesis for regenerative medicine

Figure 1 Osteocalcin secretion. In cells exposed to hypoxia (5% O₂) for 7 d followed by normoxia (21% O₂) for 7 d (HN), the level of osteocalcin increased rapidly from day 10, peaking at day 12, as compared with cells in the other groups. NN, normoxia for 14 d; NH, normoxia for 7 d followed by hypoxia for 7 d; and HH, hypoxia for 14 d. ^aP < 0.05.