Composition and concentration of lipoproteins in the serum of normal rats and rats deficient in essential fatty acids

A comparison is made of the concentration and chemical composition of serum lipoproteins of normal rats and rats deficient in essential fatty acids. The concentration of very low density lipoproteins (VLDL) and of low density lipoproteins (LDL) in serum of deficient rats is about half that found in normal rats, but the concentration of high density lipoproteins (HDL) is higher than normal and they contain an increased amount of cholesterol esters. The proportion of cholesterol that is esterified is much greater than normal in the serum of deficient rats. The deficiency of essential fatty acids also appears to result in compensating changes occurring in the composition of serum lipoproteins. In both VLDL and LDL of deficient rats the proportion of protein is raised and that of phospholipid lowered compared to normal, while the proportions of trigly ceride and cholesterol esters are unchanged.