title: Reduced circulating levels of angiotensin-(1--7) in systemic sclerosis: a new pathway in the dysregulation of endothelial-dependent vascular tone control.
abstract: OBJECTIVE
  Systemic sclerosis (SSc) impairs endothelium-dependent vasodilatation. Among angiotensin I (Ang I)-derived compounds, vasoconstrictor angiotensin II (Ang II) and vasodilator angiotensin-(1-7) (Ang-(1-7)), cleaved from ACE and neutral endopeptidase (NEP) 24.11, respectively, play an important role in vascular tone regulation. Ang-(1-7) may act independently or by activating other vasodilating molecules, such as nitric oxide (NO) or prostaglandin I2 (PGI2). Our aim was to assess, in patients with SSc, circulating levels of Ang I, Ang II and Ang-(1-7), with their metabolising enzymes ACE and NEP, and levels of NO and PGI2, and to correlate them to the main characteristics of SSc.
  
  
  METHODS
  Levels of Ang I, Ang II, Ang-(1-7), NEP, ACE, NO and PGI2 were measured in 32 patients with SSc, who were also assessed for humoral and clinical characteristics, and 55 controls.
  
  
  RESULTS
  Plasma Ang I, Ang II and Ang-(1-7) levels were lower in patients with SSc than in controls (p<0.001in all cases). When Ang II and Ang-(1-7) levels were expressed as a function of the available Ang I, lower Ang-(1-7) levels in patients with SSc than in controls were confirmed (p<0.001), while no difference was found for Ang II levels. In patients with SSc, the Ang II/Ang-(1-7) ratio indicated a prevalence of Ang II over Ang-(1-7), while in controls Ang-(1-7) was prevalent (p<0.001). Levels of ACE, NEP, NO and PGI2 were lower in patients with SSc than in controls (p<0.05 in all cases).
  
  
  CONCLUSIONS
  In patients with SSc, prevalence of the vasoconstricting Ang II over the vasodilator Ang-(1-7) suggests a dysfunction of the angiotensin-derived cascade that may contribute to dysregulation of vascular tone.
authors.affiliation: Department of Medicine and Surgery, Division of Medicine I and II and Rheumatology, Villa Monna Tessa, University of Florence, Florence, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Pignone
authors.forename: Angela Del
authors.initials: AD
authors.lastname: Rosso
authors.forename: K Bridget
authors.initials: KB
authors.lastname: Brosnihan
authors.forename: Federico
authors.initials: F
authors.lastname: Perfetto
authors.forename: Riccardo
authors.initials: R
authors.lastname: Livi
authors.forename: Ginevra
authors.initials: G
authors.lastname: Fiori
authors.forename: Serena
authors.initials: S
authors.lastname: Guiducci
authors.forename: Marina
authors.initials: M
authors.lastname: Cinelli
authors.forename: Veronica
authors.initials: V
authors.lastname: Rogai
authors.forename: Alessio
authors.initials: A
authors.lastname: Tempestini
authors.forename: Francesca
authors.initials: F
authors.lastname: Bartoli
authors.forename: Sergio
authors.initials: S
authors.lastname: Generini
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Ferrario
authors.forename: Marco Matucci
authors.initials: MM
authors.lastname: Cerinic
mesh_terms: D000803:Angiotensin I / Q000097:blood*; D000804:Angiotensin II / Q000097:blood*; D000959:Antihypertensive Agents / Q000097:blood; D011464:Epoprostenol / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000097:blood; D009569:Nitric Oxide / Q000097:blood; D010446:Peptide Fragments / Q000097:blood*; D007703:Peptidyl-Dipeptidase A / Q000097:blood; D012595:Scleroderma, Systemic / Q000097:blood*; D014662:Vasoconstrictor Agents / Q000097:blood
chemical_list: D000959:Antihypertensive Agents; D010446:Peptide Fragments; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D009569:Nitric Oxide; D000803:Angiotensin I; D011464:Epoprostenol; D007703:Peptidyl-Dipeptidase A; D015260:Neprilysin; C118790:angiotensin I (1-7)