title: Thyroid hormones are involved in 5'-nucleotidase modulation in soluble fraction of cardiac tissue.
abstract: OBJECTIVE
  To investigate the role of TH (thyroid hormones) in 5'-nucleotidase activity and expression in cardiac soluble fraction (SF).
  
  
  METHODS
  Male Wistar rats received daily injections of T4 (10, 25 or 50 μg T4/100g body weight) for 14 days to develop a hyperthyroidism condition. Thyroidectomy was performed in other animals to mimic hypothyroidism, and 14 days after surgery they were submitted to TH replacement therapy.
  
  
  RESULTS
  T4 reduced the 5'-nucleotidase activity (T4-25, P<0.05 and T4-50, P<0.01) in the SF. Conversely, hypothyroidism significantly increased the 5'-nucleotidase activity in this fraction (P<0.001) and TH replacement therapy reversed the latter result (P<0.001 compared to hypothyroid group). The analysis of protein expression in the SF showed that 5'-nucleotidase was more expressed in hypothyroid than in the control group and that the phosphorylated state of PKC observed in this condition may contribute to a possible mechanism of 5'-nucleotidase modulation by thyroid status.
  
  
  CONCLUSIONS
  Taken together, these data reveal that TH can influence adenosine production by modulating 5'-nucleotidase activity and expression, which may contribute to the cardioprotective effect and the maintenance of cardiac function under TH privation.
authors: Department of Anatomy, Laboratory of Cell Biology and Functional Anatomy (LBCAF), Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
authors: Guilherme
authors: G
authors: Cotomacci
authors: João J F
authors: JJ
authors: Sarkis
authors: Cristina R
authors: CR
authors: Fürstenau
authors: Maria Luiza M
authors: ML
authors: Barreto-Chaves
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure; D001835:Body Weight; D005786:Gene Expression Regulation; D006439:Hemodynamics; D006980:Hyperthyroidism / Q000378:metabolism; D007037:Hypothyroidism / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D009206:Myocardium / Q000378:metabolism; D009711:Nucleotides / Q000737:chemistry; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D013347:Subcellular Fractions / Q000378:metabolism; D013963:Thyroid Hormones / Q000378:metabolism*
chemical_list: D009711:Nucleotides; D013963:Thyroid Hormones; D011493:Protein Kinase C; D015720:5'-Nucleotidase