Effects of simulated microgravity on the cell growth and extracellular matrix of cultured chondrocytes

The effects of simulated microgravity on cell growth and extracellular matr ix of chondrocytes have been examined by a light microscope and a scanning electron microscope using cultured chicken embryonic chondrocytes as the mo del. No notable difference of the cell density between the rotation group a nd the control group has been found. But during the same period, the growth spots of the rotation group were sparser than those of the control group. These results indicated that the lower level of cell development and differ entiation happened in the rotation group. Observation by the scanning elect ron microscope showed that the extracellualr matrix decreased after rotatin g, and the fibres in the extracellular matrix were slighter and blurrier th an those of the control group. It is concluded that the simulated micrograv ity can affect the secreting and assembly of the extracellular matrix. The possible mechanism for them is discussed.