title: Influence of thyroid disorders on the kidney expression and plasma activity of aminopeptidase A.
abstract: OBJECTIVE
  Thyroid disorders may affect blood pressure and renal function modifying factors of the plasmatic and kidney renin-angiotensin system such as aminopeptidase A (AP A) that metabolizes angiotensin II to angiotensin III. We investigated the expression of AP A in the kidney, as well as its enzymatic activity in the plasma of euthyroid, hyperthyroid, and hypothyroid adult male rats.
  
  
  METHODS
  Hyperthyroidism was induced by daily subcutaneous injections of tetraiodothyronine. Hypothyroid rats were obtained by administration of methimazole in drinking water. Expression of AP A was determined by Western blot analysis. Plasma AP A activity was measured fluorometrically using glutamyl-β-naphthylamide as substrate.
  
  
  RESULTS
  While hyperthyroid rats exhibited lower levels of plasma AP A activity than controls, the kidney of hyperthyroid animals expressed significantly higher AP A than controls and hypothyroid animals.
  
  
  CONCLUSIONS
  A discrepancy between the high expression of AP A in kidney of hyperthyroid rats and the low activity of AP A measured in plasma and kidney of hyperthyroid animals was found. The posttranslational influence of environmental biochemical factors may be in part responsible for that divergence.
authors.forename: R
authors.initials: R
authors.lastname: Wangensteen
authors.forename: A B
authors.initials: AB
authors.lastname: Segarra
authors.forename: M
authors.initials: M
authors.lastname: Ramirez-Sanchez
authors.forename: M De
authors.initials: MD
authors.lastname: Gasparo
authors.forename: G
authors.initials: G
authors.lastname: Dominguez
authors.forename: I
authors.initials: I
authors.lastname: Banegas
authors.forename: F
authors.initials: F
authors.lastname: Vargas
authors.forename: F
authors.initials: F
authors.lastname: Vives
authors.forename: I
authors.initials: I
authors.lastname: Prieto
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004789:Enzyme Activation; D043384:Glutamyl Aminopeptidase / Q000097:blood / Q000378:metabolism*; D006044:Goiter, Nodular / Q000097:blood / Q000201:enzymology*; D006980:Hyperthyroidism / Q000097:blood / Q000201:enzymology*; D007037:Hypothyroidism / Q000097:blood / Q000201:enzymology*; D007668:Kidney / Q000201:enzymology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D043384:Glutamyl Aminopeptidase
keywords: aminopeptidases; arylamides.; hyperthyroidism; hypothyroidism