Influence of hypothyroidism on lipid contents and mRNA levels of antioxidant enzymes in rat heart.

CARMONA Y, VAZQUEZ M, CORIA M, OLIVEROS L, GIMENEZ MS.

Buenos Aires

Congreso; Reunion Anaual de la Sociedad Argentina de Biologia; 2008

Sociedad Argentina de Biologia

Influence of hypothyroidism on lipid contents and mRNA levels of antioxidant enzymes in rat heart. Carmona Y, Vazquez M, Coria M, Oliveros L, Gimenez MS. Dpto. Bqca y Cs. Biol¨®gicas. Univ. Nac. de San Luis. IMIBIO-SL CONICET.5700 San Luis. E-mail: yami.cv@hotmail.com   Various studies on the effects of thyroid status on heart lipid metabolism and oxidative stress have produced conflicting results. The aim of this work was to determinate the effects of hypothyroidism on the lipid contents and gene expression of antioxidant enzymes in heart ventricles. The hypothyroid state was induced in female virgin Wistar rats weighing 150-180 g by administration of  6-n-propyl 2-thiouracil (100 mg/L) in their drinking water for 30 days. Age-matched euthyroid rats were used as controls. Serum lipids were measured by Wiener kits and heart lipids by spectrophotometric assays after extraction by the method of Folch and separation of the different fractions by thin-layer chromatography. The mRNA of heart catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and NADPH oxidase (NOX 1) were determined by RT-PCR. The bands were quantified using the software program Scion Image from NIH and normalized by the values obtained for ¦Â-actin.  Hypothyroid state induced an increase of serum cholesterol and LDLc, and a decrease of serum and heart triglycerides (TG) (p<0.01). Heart mRNA levels of SOD (p<0.01) and NOX (p<0.001) were increased without changes in CAT and GPx, in relation to control. This suggests a prooxidant state in the heart of hypothyroid rats, which could lead to lipoperoxidation and to affect the TG content.