Long-term effect of hyperlipidemic serum on the synthesis of glycosaminoglycans and on the rate of growth of rabbit aortic smooth muscle cells in culture.

Rabbit aortic smooth muscle cells (SMCs) were successfully subcultured in 10% hyperlipidemic rabbit serum (HLS) for at least 9 passages. SMCs grown in HLS grew into higher cell densities than SMCs cultured in normolipidemic rabbit serum (NLS) for at least 4-5 passages in NLS and HLS, respectively. However, cells cultured in NLS and HLS for up to 7 passages had similar growth characteristics when they were trypsinised and seeded to grow in 10% fetal calf serum (FCS). Incorporation of [3H]glucosamine into GAGs was taken to represent their rate of synthesis. As compared with cultures incubated in 10% NLS, incubation of rabbit aortic SMCs in the presence of 10% HLS increased the synthesis of sulphated GAGs secreted into the pericellular space by 35% during the first 24 h of contact with HLS. After preincubation for one week in the presence of HLS the synthesis of sulphated GAGs secreted into the incubation medium and into the pericellular space was stimulated by 95% and 34%, respectively. The stimulation of the synthesis of sulphated GAGs by HLS continued for up to 4 weeks at least if the contact of the cells with HLS was maintained. When the cells were subcultured in the presence of NLS and HLS and seeded to grow in FCS after the 1st, 3rd and 7th trypsinisations, the synthesis of sulphated GAGs in cultures of cells from both sources was similar.