title: Role of the renin-angiotensin system on abdominal aortic aneurysms.
abstract: BACKGROUND
  Abdominal aortic aneurysm (AAA) is a complex degenerative disease, which leads to morbidity and mortality in a large portion of the elderly population. Current treatment options for AAA are quite limited as there is no proven indication for pharmacological therapy and surgery is recommended for AAA larger than 5·5 cm in luminal diameter. Thus, there is a great need to elucidate the underlying pathophysiological cellular and molecular mechanisms to develop effective therapies. In this narrative review, we will discuss recent findings concerning some potential molecular and clinical aspects of the renin-angiotensin system (RAS) in AAA pathophysiology.
  
  
  METHODS
  This narrative review is based on the material found on MEDLINE and PubMed up to April 2013. We looked for the terms 'angiotensin, AT1 receptor, ACE inhibitors' in combination with 'abdominal aortic aneurysm, pathophysiology, pathways'.
  
  
  RESULTS
  Several basic research and clinical studies have recently investigated the role of the RAS in AAA. In particular, the subcutaneous infusion of Angiotensin II has been shown to induce AAA in Apo56 knockout mice. On the other hand, the pharmacological treatments targeting this system have been shown as beneficial in AAA patients.
  
  
  CONCLUSIONS
  Emerging evidence suggests that RAS may act as a molecular and therapeutic target for treating AAA. However, several issues on the role of RAS and the protective activities of angiotensin-converting enzyme (ACE) inhibitors and Angiotensin 1 receptors blockers against AAA require further clarifications.
authors.affiliation: Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Sonaz
authors.initials: S
authors.lastname: Malekzadeh
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Fraga-Silva
authors.forename: Bram
authors.initials: B
authors.lastname: Trachet
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Montecucco
authors.forename: François
authors.initials: F
authors.lastname: Mach
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Stergiopulos
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000188:drug therapy / Q000209:etiology*; D004195:Disease Models, Animal; D005544:Forecasting; D006801:Humans; D051379:Mice; D044140:Receptor, Angiotensin, Type 1 / Q000502:physiology; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology*
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D044140:Receptor, Angiotensin, Type 1
keywords: Abdominal aortic aneurysm; angiotensin-converting enzyme; renin-angiotensin system