Hepatic lipogenesis and lipid droplets in the sucrose fed rats: effect of n-3 polyunsaturated fatty acids

RODOLFO R. BRENNER; ANA BERNASCONI; GUSTAVO HEIN; ADRIANA CHICCO; YOLANDA B. LOMBARDO

Regensburg - Alemania

Conferencia; 50 th International Conference on the Bioscince of Lipids; 2009

ICBL

The metabolic effect of the sucrose rich (62.5) diet (SRD), than mimiks the disorders of non insulin dependent diabetes type-2 was investigated to reveal dependence of liver triacylglycerols (TG) and cholesterol esters (CE) levels with lipidogenic liver X receptor (LXR) and antilipidogenic and peroxisome proliferator activated recptor (PPARalpha) and dietary polyunsaturated fatty acids (PUFA) of n-3 series. Eight months of SRD feeding produced hyperglycemia, hypertriglyceridemia and NEFA increases but nomoinsulinemia in fasted and non fasted rats correlated with hepatic increases of TG and free FAs. Correlated decreases were found of hepatic PPARalpha and its RE dependent enzymes acyl-Coa oxidase (ACO) and carnitine palmitoyl transferase-1 (CPT-1) and increases of lipogenic LXRalpha, and FA synthase (FS). Hepatic TG and CE were mainly compartmentalized in lipid droplets. Administration of cod liver oil (7%) for 2 months reverted the outnormal increases of plasmatic parameters, hepatic levels of TG and CE, and normalized PPARalpha and its RE dependent enzymes ACO and CPT-1, as well as depressing LXRalpha, FS, and glucose-6-phosphate dehydrogenase. In total liver lipids and microsomal phospholipids, biosynthetized 20:4 n-6 was depressed whereas n-3 PUFA, 20:5, 22:5 and 22:6 were enhanced increasing 16:0-22:6 n-3 PC molecular species at expense of 16:0-20:4 n-6 and 18:0-20:4 n-6 species without variation of 18:1 n-9/18:0 ratio. In hepatic lipid droplets of SRD fed rats the high levels (aprox. 33%) of 16:0 and 18:1 n-9 of TG were unmodified while 18:2 n-6 was depressed to half (aprox. 9%) and low 20:4 n-6 was replaced by similar proportion of n-3 PUFAs. In CE the low 20:4 n-6 was little decreased and n-3 PUFA appear. Therefore neutral lipids of lipid droplets do not change remarkably and behave rather as selective dynamic storage reservoir of monoenoic and saturated FAs but not of PUFA.