Journal of Dental Research, Vol 69, 1560-1563, Copyright © 1990 by International & American Associations for Dental Research Online Journals
Stimulation of proteoglycan and DNA syntheses in chondrocytes by centrifugation
H. Inoue, K. Hiasa, Y. Samma, O. Nakamura, M. Sakuda, M. Iwamoto, F. Suzuki and Y. Kato
Department of Orthodontics and Biochemistry, Faculty of Dentistry, Osaka University, Japan.
So that the effects of biomechanical forces on the proliferation of
chondrocytes and their proteoglycan synthesis could be studied,
growth-plate and articular chondrocytes were maintained separately as
packed masses in centrifuge tubes in the presence of 10% serum. In these
conditions, the cells became re-organized into cartilaginous tissue in
seven days. After ten days, they were centrifuged at gravities (g) of
1.3-27 for 24 h in a CO2 incubator. Control cells were maintained in the
CO2 incubator without centrifugation. Centrifugation of growth-plate
chondrocytes at 3 g resulted in a two-fold increase in incorporation of
[35S]sulfate into proteoglycans, but had little effect on their
[3H]thymidine incorporation into DNA. On the other hand, centrifugation of
articular chondrocytes at 3 g for 24 h caused 1.5-fold increases in both
[35S]sulfate incorporation into proteoglycans and [3H]thymidine
incorporation into DNA. These results suggest that biomechanical forces
have different effects on the growth and differentiation of articular and
growth-plate chondrocytes.
