FIG. 4.

Effects of TSH on the resorption activity of osteoclasts from ES cells cultured with four ODFs. ES cells were cultured on calcium-phosphate apatite-coated plates with or without ODFs in the absence or presence of TSH (1 mU/mL) for 12 days. When TRAP-positive osteoclasts appeared, the cells were removed with a solution of 5% sodium hypochlorite and pits (clear areas) were counted microscopically. (A) Resorbed lacunae (arrows) on the plates were photographed under an inverted microscope ( × 200). Note that compared with ODFs treatment, TSH (1 mU/mL) significantly decreased the resorption activity of osteoclasts. (B) The number of resorption pits in TSH− and TSH+ cultures was determined by light microscopy in five randomly chosen fields. Data are presented as mean ± SEM of triplicate cultures. The p-value, calculated by comparing ODFs treatment versus ODFs treatment in the presence of TSH, was < 0.01.