OBJECTIVEAlkaline phosphatase (ALP) and osteocalcin (OC) are the markers of new bone formation. Quantitative study of ALP and OC in the process of new bone formation helps to understand the ongoing of this cascade and contributes to make diagnosis in clinical treatment.

METHODS8-week-old male C57BL/6J mice and primary osteoblasts from neonatal C57BL/6J mice calvaria were used in this experiment. HE staining, Northern blot and Real Time PCR methods were employed to detect the histological changes and the expression pattern of ALP and OC.

RESULTSIn vivo study showed that after fracture the expressions of both ALP and OC kept on increasing which were peaked on the 10 day, then started decreasing gradually. In vitro study on primary osteoblasts showed that the expressions of ALP and OC reached peak on the 14th day in differentiation culture medium and started decreasing from this time point till the 21st day.

CONCLUSIONThe expression of ALP and OC in the process of new bone formation parallels with the development of osteoblasts, it increases with the differentiation of osteoblasts and becomes decreasing with the maturation of osteoblasts. The reciprocal relationship between the expression pattern of ALP and OC and development of osteoblast helps to maintain homeostasis.