OBJECTIVETo establish a more stable method to isolate osteocytes in vitro, and then to find the differences with osteoblast biological characteristics.

METHODSOsteocytes and osteoblasts were isolated from the bone tissue of 3-day-old rats using sequential collagenase digestion. The cells were identified through cell morphology after 24 hours later. Alkaline phosphatase (ALP) kit was used to stain the first generation cells by Kaplow-way, the bone gla protein (BGP) of the cells were stained by immunocytochemitry. Measured ALP and computed its activity.

RESULTSOsteocytes and osteoblasts showed obviously differences in cell morphology. Osteocytes were star-shaped or dendrite-shaped within more dendrites, while osteoblasts were spindle-shaped with short dendrites. Osteocytes were negative for ALP, but osteoblasts were positive; Osteocytes were more positive for BGP, and osteoblasts were less positive. The secretion of ALP in osteocytes was lower than that of osteoblasts.

CONCLUSIONOsteocytes can be isolated and cultured in vitro. These characteristics of osteocytes are apparently difference with those of osteoblasts.