Hypothyroidism, thyroid hormone receptors and inflammation in the heart

CARMONA Y , OLIVEROS L, GIMENEZ MS.

Puerto Madryn

Congreso; SAIB; 2010

SAIB

Hypothyroidism, thyroid hormone receptors and inflammation in the heart Carmona Y, *Gomez-Mejiba SE, *Ramirez DC, Oliveros L,Gimenez MS. UNSL, IMIBIO-SL CONICET. *Oklahoma Medical Research Foundation, OK,USA. E-mail: yami.cv@hotmail.com The superfamily of nuclear receptors includes a number of transcription factors, which activity regulates inflammation, oxidative stress and metabolism. However, the effect of hypothyroidism on heart inflammatory profile is unclear. Herein, we sought to determine whether hypothyroidism affects nuclear receptors’ expression and inflammation in the heart. To accomplish this aim, a hypothyroidism model was produced in female virgin Wistar rats (150-180 g body weight) by treating them with (hypothyroid, HT) or without (euthyroid, ET) 100 mg/L of 6-n-propyl 2-thiouracil in their drinking water. After 30 days of treatment HT and ET rats were sacrificed and their heart excised for the determination of PPARã, TNF-á, TRá, TRâ and â-actin (internal control) mRNA by RT-PCR. The protein level of cyclooxygnease-2 (COX-2), inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) was determined by Western blot. Confocal imaging of the heart tissue and RT-PCR data are consistent with a reduced expression of TRa1 and TRb1, whereas increased COX-2 and iNOS proteins, in the heart of HT with respect to ET rats. However, we observed no changes in eNOS, PPAR-g mRNA and TNF-a. Our results suggest that hypothyroidism affects the inflammatory profile in the heart. These results impact our understanding of hypothyroidism-associated heart diseases.