Dimethyl sulfoxide alterations of macromolecular synthesis by chick limb mesenchymal cells in vitro

Earlier the authors reported that dimethyl sulfoxide (DMSO) inhibited the chondrogenesis of chick limb cells in vitro at concentrations of 30 mg/ml or greater. The present study was undertaken to determine if inhibition by DMSO might be due to an alteration in protein and/or DNA synthesis by the treated cells. Micromass cultures were prepared from stage 23-25 chick limb mesenchyme. The cells were treated with either 30 or 40 mg of DMSO/ml of culture medium for 24, 48, and 72 hr. After each treatment, protein and DNA synthesis were analyzed by the incorporation of (/sup 3/H)-leucine and (/sup 3/H)-thymidine, respectively. Cell cultures exposed to 40 mg DMSO/ml for 24 hr showed a significant decrease in protein synthesis, while there was no decrease in protein synthesis for cells treated with 30 mg DMSO/ml. At both 48 and 72 hr treatment with 30 mg of DMSO, there was a decrease in (/sup 3/H)-leucine incorporation. The thymidine studies indicated that there was a significant decrease in DNA synthesis as early as 24 hr for both DMSO concentrations. These findings suggest that the inhibition of chondrogenesis following DMSO treatment may be related to alterations in macromolecular synthesis possibly including extracellular cartilage matrix production.