title: Nitric oxide (NO) and asymmetric dimethylarginine (ADMA): their pathophysiological role and involvement in intracerebral hemorrhage.
abstract: OBJECTIVE
  Nitric oxide (NO) has a variety of functions in physiological systems, particularly in the vasculature and the central nervous system. Currently, the imbalance of the pathway involving nitric oxide, nitric oxide synthase, and asymmetric dimethylarginine (NO-NOS-ADMA) is increasingly discussed in connection with endothelial dysfunction. Knowledge about the role of this pathway in intracerebral hemorrhage (ICH), which represents the most devastating stroke subtype, is increasing but still sparse. This article aims to review the current knowledge about the role and metabolism of NO and ADMA. It will also address the role of the NO-NOS-ADMA pathway in ICH and delineate some questions that should be addressed by future studies.
  
  
  METHODS
  A literature search regarding the data about NO, NOS, and ADMA and its role in ICH was conducted in PubMed.
  
  
  RESULTS
  Experimental data from cell culture and animal models indicate that, after the occurrence of ICH, neuronal and inducible nitric oxide synthases (nNOS and iNOS) are both overexpressed and uncoupled through the induction of blood compound metabolites, including thrombin and inflammatory mediators. ADMA, the most potent endogenous inhibitor of NOS, is also overproduced following dysregulation of its metabolizing enzymes. Dysfunction of the NO-NOS-ADMA pathway results in cell death, blood-brain barrier (BBB) disruption, and brain edema via different pathological mechanisms. However, the available data from clinical studies are still rare and partially contradictory.
  
  
  CONCLUSIONS
  Experimental data suggest an important role for the NO-NOS-ADMA pathway for secondary injury after ICH. Since the literature shows contradictory results, further studies are needed to address current confusion.
authors.affiliation: Department of Neurology, Hannover Medical School, Germany. selina1808@gmail.com
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Hans
authors.initials: H
authors.lastname: Worthmann
authors.forename: Milani
authors.initials: M
authors.lastname: Deb
authors.forename: Shufen
authors.initials: S
authors.lastname: Chen
authors.forename: Karin
authors.initials: K
authors.lastname: Weissenborn
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000502:physiology; D002543:Cerebral Hemorrhage / Q000201:enzymology / Q000503:physiopathology*; D006801:Humans; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000502:physiology
chemical_list: D009569:Nitric Oxide; C018524:N,N-dimethylarginine; D001120:Arginine; D019001:Nitric Oxide Synthase