Vitamin A regulates the expression of genes involved in the fatty acid beta oxidation in rat liver.

VEGA V.; ANZULOVICH A.C.; VARAS S.M.; BONOMI M.R.; GIMÉNEZ MS; OLIVEROS L

Rosario, Santa Fe

Congreso; XLII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2006

SAIB

We have previously showed in the rat heart that vit A deficiency alters the mitochondrial lipid contents, decreases the Acetil CoA Carboxilasa (ACC) activity, and increases the Carnitina Palmitoiltransferasa I (CPT I) activity, key enzyme in the fatty acid beta-oxidación. Here, we determined by RT-PCR in heart the mRNA expression of ACC2, isoform associated to the mitochondria, CPT I and retinoic acid receptors (RAR). Male Wistar rats at 21 d age were weaned onto either a vit A deficient diet (-A) or the same diet with 8 mg retinol/kg diet (control). They were fed for 3 months. Also, a ?A group was refeed by 15 days with control diet (-A refeed). Serum and liver Vit A levels were measured by HPLC.  Statistical analysis by ANOVA. In ?A rats the mRNA expression of CPT I increased (p< 0.01), while that of ACC2 decreased (p< 0.002), compared to control. These results were related with the enzyme activities previously determined. The RAR mRNA levels decreased (p< 0.01) in ?A heart. Vit A restitution to the diet reversed the CPT I and RAR mRNA levels, whitout change in the ACC2 mRNA. In addition to the effects of vit A deficiency on those genes, the possibility that a lower availability of the endogenous inhibitor of CPT I, malonyl-CoA, can be involved in the regulation of the beta-oxidation process could be considered since we have previously determined a decrease of the ACC activity.