Effects of hypothyroidism on oxidative stress in heart of pregnant rats.

CARMONA Y., OLIVEROS L, GIMENEZ MS

Congreso; SOBIO 2010; 2010

Sociedad de Biología de Cuyo

Effects of hypothyroidism on oxidative stress in heart of pregnant rats. Carmona Y, Oliveros L, Gimenez MS. Univ. Nac. de San Luis IMIBIO-SL-CONICET.5700 San Luis. E-mail: yami.cv@hotmail.com Hypothyroidism is associated to alterations in physiological functioning of heart muscle. Various studies on the effects of thyroid status on heart oxidative stress have produced conflicting results. In this work we studied the effect of hypothyroidism on oxidative stress in ventricles of heart from pregnant rats. The hypothyroid state was induced by  6-n-propyl-2-thiouracil (100mg/g body wt) in drinking water given to female Wistar rats (150-180 g body wt) starting 8 days before mating until day 21 of pregnancy (HP group) or for 30 days in virgin rats (HV group). The mRNA expressions (by RT-PCR, using â-actin as internal control) and activities of NADPHoxidase (Nox2), superoxide dismutase (SOD), catalase (CAT) and gluthathione peroxidase (GPx) were measured in the heart. Also, TBARs (as MDA) and carbonyl groups content were determined. In HP rats, the hypothyroidism did not have an effect on all these parameters, while in HV rats the hypothyroidism increased carbonyl content and GPx activity (p<0.05), compared with control. The pregnancy induced an increase of TBARS content (p<0.001), SOD and CAT activities (p<0.001) and mRNA levels of Nox2, CAT and SOD, and a decrease of carbonyl content, compared with virgin rats. In our experimental model the redox changes induced by pregnancy in the heart are not affected by the hypothyroidism.