EFFECT OF FISH OIL ON THE UNSATURATED FATTY ACID METABOLISM IN DYSLIPEMIC SUCROSE FED RATS

RODOLFO R. BRENNER; ANA BERNASCONI; MAURO MONTANARO; MAGALÍ PELLON-MAISON; GABRIELA FINARELLI; GUSTAVO HEIN; ADRIANA CHICCO; YOLANDA B. LOMBARDO

Maastricht, Netherlands

Conferencia; 49TH INTERNATIONAL CONFERENCE ON THE BIOSCIENCE OF LIPIDS; 2008

ICBL

A sucrose-rich diet (SRD) compared to a starch diet induces in therat time-dependentmetabolic disorders and insulin resistance similarto the metabolic syndrome and like those found in diabetestype 2 with hypertriglyceridemia, evolving after 8 months to a normoinsulinemia.In this study we examined how dietary n-3 FAmodify hepatic nuclear receptors LXR, PPAR-alpha, transcription factorSREBP-1c, desaturases delta-9, delta-6 and delta-5 mRNA and activity andthe composition of FA and phospholipids molecular species in ratsfeeding the SRD for a long term. SRD, in animals feeding 8% cornoil, enhanced the delta6 desaturase and less significantly the delta-5. Thereplacement of 8% corn oil by 1% corn oil plus 7% cod oil for twomonths decreased the SCD-1 parameters, but did not modify thedelta6 and delta5 desaturases in control animals. It did not modify theseparameters and the insulinemia in rats feeding the SRD. In totalliver and microsomal lipids the SRD evoked no significant variationof monoenoic acid percentage, but increased 20:4 n-6 anddecreased 22:6 n-3. The incorporation of fish oil in both dietsevoked similarly no variation of monoenoic acids, a decrease of20:4 n-6 and increases of all the n-3 acids. These results suggestthat the changes evoked by the fish oil are mainly produced bycompetition between dietary n-6 and n-3 acids and not throughdesaturases activity modification. The function of LXR, PPAR-alpha andSREBP-1c is discussed.