title: The endothelial-erectile dysfunction connection: an essential update.
abstract: BACKGROUND
  The endothelial monolayer plays a crucial role in the vasodilation and hemodynamic events involved in erection physiology. Due to its relevant functions, a close link has been established between endothelial integrity and erectile dysfunction (ED). Endothelial dysfunction is induced by the detrimental actions of vascular risk factors (VRFs), identified as common correlates for the development of cardiovascular disease and ED. It is currently recognized that ED is the early harbinger of a more generalized vascular systemic disorder, and, therefore, an evaluation of endothelial health in ED patients should be of prime relevance. Several noninvasive methods for endothelial function assessment have been proposed, including the Penile Nitric Oxide Release Test (PNORT).
  
  
  OBJECTIVE
  To highlight the most recent gathered knowledge on basic and clinical mechanisms underlying loss of cavernosal endothelial function promoted by VRFs and to discuss local and systemic methods for endothelial function assessment in ED individuals, focusing on the PNORT.
  
  
  METHODS
  A complete revision on the novel basic and clinical links between endothelial and ED.
  
  
  METHODS
  A systematic review of the literature regarding the aforementioned issues.
  
  
  RESULTS
  Risk factor-associated cavernosal endothelial dysfunction is mostly induced by unifying mechanisms, including oxidative stress and impaired endothelial nitric oxide functional activities, which present clinically as ED. Several techniques to evaluate endothelial dysfunction were revised, with advantages and limitations debated, focusing on our detailed expertise using the PNORT method.
  
  
  CONCLUSIONS
  The established endothelial-erectile dysfunction connection was thoroughly revised, from basic mechanisms to the clinical importance of endothelial dysfunction assessment as diagnosis for generalized vascular disease. Further studies are required to disclose efficient approaches to repair disabled endothelium and both restore and prevent endothelial dysfunction.
authors.affiliation: Faculty of Medicine of the University of Porto, Department of Biochemistry (U38-FCT), Porto, Portugal. carcosta@med.up.pt
authors.forename: Carla
authors.initials: C
authors.lastname: Costa
authors.forename: Ronald
authors.initials: R
authors.lastname: Virag
mesh_terms: D000375:Aging; D006152:Cyclic GMP; D004730:Endothelium, Vascular / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D018783:Impotence, Vasculogenic / Q000503:physiopathology*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D010410:Penile Erection; D010413:Penis / Q000098:blood supply*; D010991:Plethysmography; D012307:Risk Factors; D015398:Signal Transduction; D013223:Statistics as Topic
chemical_list: D009569:Nitric Oxide; D006152:Cyclic GMP