[Effect of interleukin-6 on the chondrocytes in the cartilage endplate of rabbits in vitro].

OBJECTIVE

To evaluate the effect of interleukin-6 (IL-6) on the biological behaviors of the chondrocytes in the cartilage endplate of rabbits.

METHODS

Chondrocytes isolated from the cartilage endplate of New Zealand rabbits, verified for their biological characteristics by such means as toluidine blue staining for type II collagen, were treated with IL-6 at different concentrations. The proliferation of the chondrocytes was evaluated by MTT assay at different time points following the treatment, the cell cycle changes were determined by flow cytometry and the changes of aggrecan and type II collagen mRNAs detected by RT-PCR.

RESULTS

At the concentrations of 10, 50 and 100 ng/ml, IL-6 did not obviously affect the rate of chondrocyte proliferation. IL-6 at 50 ng/ml resulted in no obvious changes of the cell cycle of the chondrocytes, but significantly decreased the expression of collagen IIa mRNA.

CONCLUSION

IL-6 has no effect on the proliferation and cell cycle of the chondrocytes, but at higher concentrations, it inhibits matrix synthesis of the chondrocytes to promote intervertebral disc degeneration.