Effect of serum and liver extracts from hypercholesterolemic rats on the synthesis of collagen by isolated aortas and cultured aortic smooth muscle cells.

Rats were made hypercholesterolemic by feeding them a high-cholesterol, olive oil diet for one week. The effect of sera and 35,000 X g supernatants of liver homogenates on collagen synthesis was studied in isolated aortas, cultured arterial smooth muscle cells and the same cells in suspension. Compared to the preparations from normal rats, the liver preparations from hyperlipidemic rats stimulated collagen synthesis in both isolated aortas and cultured smooth muscle cells by about 25%. In these test systems hyperlipidemic serum was without effect but when added to smooth muscle cells incubated in suspension, produced a significant increase in the amount of collagen secreted. Hyperlipidemic serum caused an increase of about 50% in the incorporation of [3H]-thymidine by cultured smooth muscle cells.