Synthesis of glycosaminoglycans by cultured rabbit smooth muscle cells

Rabbit aortic smooth muscle cells were evaluated for their ability to synthesize and accumulate glycosaminoglycans (GAGs). Because of the sensitivity of the microtechniques utilized, it is possible to determine the specific radioactivity of the GAGs obtained after radioactive incorporation of [35S]SO4(2-) and [14C]glucosamine. Data obtained at various incubation times indicate that the distribution of the GAGs secreted by the cells into the medium is different from that retained by the cell layer. Hyaluronic acid was shown to be the most abundantly produced GAG, and much of this GAG does not appear to be incorporated into the extracellular matrix. Also, a high percentage of the total chondroitin sulfate B synthesized was secreted into the medium. On the other hand, most of the heparan sulfate and chondroitin sulfate C/A synthesized seems to be associated with the cell layer. These results are consistent with those found in whole rabbit aorta.