The Porcine Ovarian Follicle. VI. Comparison of Fatty Acid Composition of Serum and Follicular Fluid at Different Developmental Stages

The free and esterified fatty acid composition of pig serum and pig ovarian follicular fluid (POFF) samples were determined at three different developmental stages of the follicle. The most striking difference between pig serum and POFF was that the contents of free arachidonic (20:4 ω6) and free docosatetraenoic (22:4 ω6) acids were ∿4 times higher in POFF than in serum. The high content of 20:4 ω6 in POFF may relate to the synthesis of prostaglandins. Free fatty acid (FFA) concentrations in POFF also decreased with follicular maturation. The concentration of POFF-FFA from large sized follicles was similar to that of pig serum. Variations in the esterified fatty acid profile with respect to follicle development were particularly noticeable in the phosphatidylcholine fraction. The decrease of palmitic (16:0) and oleic (18:1) acids and the increase of stearic (18:0) acid and polyunsaturated fatty acids (mainly 20:4 ω6) in ovarian fluid as follicles increased in size from <2 to >6 mm suggest that fatty acid chain elongation and desaturation increase with follicular maturation.