Hypercholesterolemia and aortic glycosaminoglycans of rabbits fed semi-purified diets containing sucrose and lactose.

This study was designed to evaluate the role of dietary sucrose and lactose in a semipurified diet as initiating factors for aortic glycosaminoglycan (GAG) and lipid changes. Rabbits were fed sucrose or lactose as 40% by weight of a semi-purified, cholesterol-free diet for 10 weeks. At the end of the feeding period there was no macroscopic evidence of atherosclerosis. Sucrose-fed rabbits had significantly higher plasma cholesterol and phospholipid levels than the lactose-fed rabbits and triglyceride levels were variably elevated in the sucrose group. Analysis of plasma lipoproteins indicated that sucrose elevated VLDL and LDL when compared to lactose. Only the higher molecular weight form of apo B (apo BH) could be demonstrated when apo B components of isolated lipoproteins were analyzed. Sucrose-fed rabbits had significantly more aortic cholesterol, cholesteryl ester and phospholipid and tended to have more GAG/mg dry defatted aorta than the lactose-fed rabbits. Plasma cholesterol levels correlated with aortic lipids and in the sucrose group, aortic cholesteryl ester and cholesterol were strongly correlated with aortic GAG particularly hyaluronic acid. Results suggest that the semi-purified diet alters aortic GAG composition but in order for the initiation of cholesterol accumulation a significant increase in plasma lipoprotein cholesterol is necessary.