title: Effect of vitamin D3 on thyroid function and de-iodinase 2 expression in diabetic rats.
abstract: OBJECTIVE
  This study aimed to assess the effect of vitamin D3 administration to diabetic rats on thyroid profile and deiodinase 2 (D2).
  
  
  METHODS
  Thirty male Wistar rats were included into three groups; control, streptozotocin-induced diabetic and diabetic supplemented with vitamin D3 groups. Ten weeks later, serum levels of free T4, free T3 and TSH were measured. Tissue homogenates from liver, kidney, muscle, femur bone, heart and brain were obtained and assessed for D2 mRNA.
  
  
  RESULTS
  Diabetic rats demonstrated significant increase in free T4 and significant decrease in free T3. These changes were ameliorated by vitamin D3 administration. D2 mRNA was significantly reduced in all tissue homogenates obtained from diabetic rats, while vitamin D3 treatment significantly enhanced D2 in liver and brain homogenates.
  
  
  CONCLUSIONS
  Diabetes mellitus inhibited peripheral conversion of T4 into T3 secondary to reduction in D2 expression. Vitamin D3 greatly corrected the alterations in thyroid profile and D2 expression.
authors.affiliation: a Physiology Department, Faculty of Medicine , King Abdulaziz University , Jeddah , Saudi Arabia .|b Physiology Department, Faculty of Medicine , Cairo University , Giza , Egypt , and.
authors.forename: Zienab
authors.initials: Z
authors.lastname: Alrefaie
authors.affiliation: a Physiology Department, Faculty of Medicine , King Abdulaziz University , Jeddah , Saudi Arabia .|c Physiology Department, Faculty of Medicine , Ain Shams University , Cairo , Egypt.
authors.forename: Hossam
authors.initials: H
authors.lastname: Awad
mesh_terms: D000818:Animals; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D002762:Cholecalciferol / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D007453:Iodide Peroxidase / Q000235:genetics / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013961:Thyroid Gland / Q000187:drug effects / Q000502:physiology*; D000097564:Iodothyronine Deiodinase Type II
chemical_list: D050071:Bone Density Conservation Agents; D002762:Cholecalciferol; D007453:Iodide Peroxidase; D012333:RNA, Messenger; D000097564:Iodothyronine Deiodinase Type II
keywords: Deiodinase 2; diabetes mellitus; thyroid hormones; vitamin D3