Docosahexaenoic acid and eicosapentaenoic acid affect ovarian prostaglandin levels differently in rats

Prostaglandins (PGs) play a key role in the regulation of ovulation. Typically, ingestion of the long-chain n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) has been found to decrease, whereas arachidonic acid (ARA) increases PG biosynthesis in most systems. We hypothesized that DHA and EPA would decrease ovarian PGE₂, enhancing ovulation, with combined EPA and DHA having the greatest effect, whereas ARA would increase PGE₂, suppressing ovulation. Our objective was to determine how 0.3-g/100-g diet DHA and EPA alone or combined, or ARA would affect tissue composition, ovulation, and PG synthesis in rats. After 27 days on diet and ovulation induction, ovaries were isolated and analyzed from 22 pups per diet. Eicosapentaenoic acid alone reduced ovarian n-6 PUFA attributable to reduced ARA incorporation. Arachidonic acid ingestion reduced and EPA enhanced ovarian n-3 PUFA to levels above what was seen with DHA or DHA/EPA combinations. Docosahexaenoic acid alone increased total PGE 1.5-fold over control, whereas neither differed from the remaining treatments. Increased total PGE with DHA was attributable to elevated PGE₃ with PGE₂ unchanged by diet, and PGE₃ only increased with DHA ingestion alone. Total PGF differed from control with the highest DHA intake, alone or combined with EPA, or with ARA ingestion (P < .05). Increased PGF with DHA was attributable to increased PGF_3α. Experimental diets did not alter ovulation from control. Results indicate that DHA and EPA consumption at human achievable doses differently alters ovarian phospholipids and PGs associated with ovulation with potential for significant 3-series PG without significantly perturbing ovulation.