FREQUENCY OF (N-3) POLYUNSATURATED FATTY-ACID CONSUMPTION INDUCES ALTERATIONS IN TISSUE LIPID-COMPOSITION AND EICOSANOID SYNTHESIS IN CD-1 MICE

This study assessed the effect of frequency of consumption of a diet containing 10 g fat/100 g, with a (n-3):(n-6) polyunsaturated fatty acid (PUFA) ratio of 0.5, on tissue fatty acid composition and eicosanoid synthesis in CD-1 mice. With greater (n-3) PUFA consumption frequency, hepatic and peritoneal cell (n-3) PUFA levels changed to 14.4 +/- 1.3 and 12.4 +/- 0.9 mol/100 mol, respectively, from 2.4 +/- 0.3 and 1.9 +/- 0.3 mol/100 mol in control animals consuming a diet without (n-3) PUFA. Hepatic and peritoneal cell (n-6) PUFA levels were reduced to 6.4 +/- 0.5 and 7.6 +/- 0.5 mol/100 mol, respectively, with daily (n-3) PUFA consumption, compared with 23.6 +/- 0.7 and 17.9 +/- 0.7 mol/100 mol in control animals. Prostaglandin E, 6-keto-prostaglandin F-1 alpha, and 4-series sulfidopeptide leukotriene biosyntheses reflected frequency of (n-3) PUFA consumption, with daily (n-3) PUFA consumption reducing prostaglandin E, consumption of (n-3) PUFA every other day reducing 6-keto-prostaglandin F-1 alpha, and (n-3) PUFA consumption every 3 d reducing leukotriene C-4 and leukotriene E(4). Leukotriene C-5 and leukotriene E(5) changed from undetectable in animals consuming the control diet to >40% of total leukotriene production in animals consuming (n-3) PUFA daily. Daily to biweekly consumption of fish or fish oil [1.26-0.63 g/wk of (n-3) PUFA, 6-3% of energy] may be a means for changing eicosanoid production. Consumption of (n-3) PUFA less often than twice a week may not change eicosanoid synthesis.