Ingestion of n-3 polyunsaturated fatty acids and ovulation in rats

The effects of different ratios of dietary (n-3):(n-6) polyunsaturated fatty acids on prostaglandin E, prostaglandin F2 alpha and ovulation in rats were assessed. Dietary (n-3) polyunsaturated fatty acids were incorporated, by ovarian phospholipids with ovarian tissue enrichment, with (n-3) polyunsaturated fatty acids enhancing, and (n-6) polyunsaturated fatty acids reducing, the number of ova released in immature rats primed with pregnant mares' serum gonadotrophin and human chorionic gonadotrophin. Incorporation of (n-3) polyunsaturated fatty acids appeared to enhance ovulation by altering total prostaglandin E production. This effect may be induced by changes in the prostaglandin E3:E2 ratio and the synthesis of less biologically active prostaglandin E3, or by dilution of the anti-ovulatory properties attributable to prostaglandin E2. High incorporation of dietary (n-6) polyunsaturated fatty acids may lead to reduced ovulation through excessive production of prostaglandin E2. Prostaglandin E or F2 alpha and alterations in tissue phospholipid composition inhibited progesterone release, and inhibition was independent of the series of prostaglandin produced. This study provides evidence that dietary lipids affect ovulation in rats with possible implications for reproduction in other vertebrates.