The Factor Affecting the Spreading of Chondrocytes upon Inorganic Substrate
The effect of conditioned medium (CM) prepared from mass-cultures of chick embryonic cells was studied on the spreading behaviour of chondrocyte derived from sterna of 16-day-old chick embryos. Freshly dissociated chondrocytes exhibited a quite rounded form, and this shape did not change when they were cultured with fresh medium (Eagle's MEM + 6% foetal calf serum) in vitro for several days. Non-dialysable material(s) in CM added into the fresh medium stimulated the formation of pseudopods of chondrocytes, without primarily affecting the synthesis of chondroitin sulphates. Such an activity of CM was not lost after boiling, but it was lost following treatment with proteases. The chondrocytes covered with newly deposited acidmucopoly-saccharides were insensitive to the effect of CM, but they became sensitive to form pseudopods after treatment of the cells with chondroitinase. These results suggest that CM contains a macromolecular material(s) to enhance the motility or adhesiveness of chondrocytes.