OBJECTIVETo study the biological features and osteoblast/adipocyte phenotypes of bone marrow stromal cells (BMSCs) of Sprague-Dawley (SD) rats with Type I osteoporosis by induced culture.

METHODSSix-month-old SD rats were used in this study. 16 female rats were randomly divided into two groups. Eight rats were ovariectomied as experimental group to establish the modle of Type I osteoporosis, while other rats received sham-operation. Three month later BMSCs of 16 rats were isolated by discontinueous gradient centrifugation and then plated in alpha-MEM medium as primary culture. Secondary harvested cells were cultured for 14 days in alpha-MEM medium supplemented with dexamethasone, ascorbic acid, vitamin D3, beta-glycerophosphate or dexamethasone, 3-isobutyl-1-methylxanthine, insuline, and indomethine. The cells were screened by inverted microscope each day and cell growth was studied with cell counting. The osteoblast and adipocyte phenotypes were verified by cytochemistry staining, counted the percentage of positive stained cells.

RESULTSThe weight and bone mineral density of rats were statistically different between experimental group and control group. Gomori and Von Kossa's staining demonstrated positive osteoblast phenotypes of alkaline phosphatase and mineralized nods by osteogenic inducer, while Oil Red O staining identified BMSCs treated with adipogenic medium resulted in adipocyte formation and there was no significant difference in the percentage of positive stained cells between two groups.

CONCLUSIONThe model of Type I osteoporosis has been established successfully. BMSCs from SD rats with osteoporosis maintain their differentiation potential.