Effect of sera from hyperlipidemic subjects and high-density lipoproteinemic runners on the synthesis of DNA and glycosaminoglycans by cultured human aortic smooth muscle cells.

Effects of hyperlipidemic, normolipidemic and high-density-lipoproteinemic (HD lipoproteinemic) sera from active runners were studied on cultured human aortic smooth muscle cells. The synthesis of DNA, hyaluronic acid and sulphated glycosaminoglycans (GAGs) in the presence of the various sera was measured by the incorporation of [3H]-thymidine and [3H]-glucosamine. The HD lipoproteinemic sera from runners stimulated the synthesis of DNA and sulphated GAGs less than normolipidemic and hyperlipidemic sera. The hyperlipidemic sera stimulated the synthesis of DNA slightly more than the other sera, but only after a 24 h preincubation. Accordingly, the concentration of HDL-cholesterol in serum was negatively correlated with the synthesis of DNA (r = -0.77, P less than 0.01) and sulphated glycosaminoglycans (r = -0.81, P less than 0.01). The sulphated GAGs/hyaluronate ratio was smaller in the presence of HD lipoproteinemic serum as compared with the other sera. The proliferation of aortic smooth muscle cells and the rate at which they synthesize sulphated GAGs have been considered important during the initiation of atherosclerosis in vivo. The present results suggest that sera having differences in the relative amounts of various lipoprotein fractions differ significantly in their influence on both of these arterial smooth muscle cell functions in vitro.