title: Human red blood cells alterations in primary aldosteronism.
abstract: BACKGROUND
  Aldosterone (Aldo) effects include NADPH oxidase activation involved in Aldo-related oxidative stress. Red blood cells (RBCs) are particularly sensitive to oxidative assault, and both the formation of high molecular weight aggregates (HMWAs) and the diamide-induced Tyr phosphorylation (Tyr-P) level of membrane band 3 can be used to monitor their redox status.
  
  
  OBJECTIVE
  The Aldo-related alterations in erythrocytes were evaluated by comparing in vitro evidence.
  
  
  METHODS
  This was a multicenter comparative study.
  
  
  METHODS
  The study included 12 patients affected by primary aldosteronism (PA) and 6 healthy control subjects (HCs), whose RBCs were compared with those of patients with PA. For in vitro experiments, RBCs from HCs were incubated with increasing Aldo concentrations.
  
  
  METHODS
  The Tyr-P level, band 3 HMWA formation, and autologous IgG binding were evaluated.
  
  
  RESULTS
  In patients with PA, both Tyr-P levels and band 3 HMWAs were higher than those in HCs. RBCs from HCs were treated with increasing Aldo concentrations in both platelet-poor plasma (PPP) and charcoal-stripped (CS)-PPP. Results showed that Aldo had dose- and time-dependent effects on band 3 Tyr-P and HMWA formation in CS-PPP more than in PPP. These effects were almost completely prevented by canrenone or cortisol. Aldo-related membrane alterations led to increased autologous IgG binding.
  
  
  CONCLUSIONS
  Erythrocytes from patients with PA show oxidative-like stress evidenced by increased HMWA content and diamide-induced band 3 Tyr-P level. Aldo effects are mediated by the mineralocorticoid receptor, as suggested by the inhibitory effects of canrenone, an antagonist of Aldo. In CS-PPP, in which Aldo induces remarkable membrane alterations leading to IgG binding, Aldo may be responsible for premature RBC removal from circulation.
authors.affiliation: Department of Molecular Medicine-Biological Chemistry, University of Padua, Viale G. Colombo 3, 35131 Padua, Italy. luciana.bordin@unipd.it
authors.forename: Luciana
authors.initials: L
authors.lastname: Bordin
authors.forename: Gabriella
authors.initials: G
authors.lastname: Donà
authors.forename: Chiara
authors.initials: C
authors.lastname: Sabbadin
authors.forename: Eugenio
authors.initials: E
authors.lastname: Ragazzi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Andrisani
authors.forename: Guido
authors.initials: G
authors.lastname: Ambrosini
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Brunati
authors.forename: Giulio
authors.initials: G
authors.lastname: Clari
authors.forename: Decio
authors.initials: D
authors.lastname: Armanini
mesh_terms: D000328:Adult; D000368:Aged; D001457:Anion Exchange Protein 1, Erythrocyte / Q000032:analysis; D003958:Diamide / Q000494:pharmacology; D004903:Erythrocyte Aggregation; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000097:blood*; D007074:Immunoglobulin G / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D007074:Immunoglobulin G; D003958:Diamide