A comparison of the lipid classes and essential fatty acid content of rat plasma lipoproteins and ovary.

Plasma lipoproteins, prepared from the blood of superovulated rats by precipitation with phosphotungstate/Mg2+, were similar to HDL and LDL prepared by 24 hr centrifugation. Analyses of the fatty acid compositions of the major lipid classes in HDL, LDL and ovary revealed that the esterified fatty acids of plasma were markedly shorter and more saturated than those of the ovary. Elongation of essential fatty acids by ovary may be important in disposing of carbon fragments generated by the incomplete oxidation of fatty acids during steroidogenesis. The function of HDL and/or LDL in supplying polyunsaturated fatty acids to ovary may be more important than their role in delivering cholesterol, which the ovary can make.