title: Circulating nitric oxide products do not solely reflect nitric oxide release in cirrhosis and portal hypertension.
abstract: BACKGROUND
  Patients with cirrhosis often develop a systemic vasodilatation and a hyperdynamic circulation with activation of vasoconstrictor systems such as the renin-angiotensin-aldosterone system (RAAS), and vasopressin. Increased nitric oxide (NO) synthesis has been implicated in the development of this state of vasodilation and pulmonary dysfunction including increased exhaled NO concentrations. Circulating metabolites (NO(x)) may affect the systemic and pulmonary NO-generation. However, the relations of these abnormalities to the haemodynamic changes remain unclear.
  
  
  OBJECTIVE
  The aims of the present study were to measure changes in exhaled NO in relation to circulating NO(x), RAAS, and haemodynamics.
  
  
  METHODS
  Twenty patients (eight child class A and 12 class B patients) underwent a liver vein catheterization with determination of splanchnic and systemic haemodynamics. Circulating NO(x) and exhaled NO were determined in the supine and sitting positions and related to haemodynamics, RAAS and lung diffusing capacity (D(L)CO). Eight matched healthy individuals served as controls.
  
  
  RESULTS
  All patients with cirrhosis had portal hypertension. We found no significant difference in exhaled NO between patients and controls and no changes from the supine to the sitting position. Exhaled NO in the patients correlated significantly with plasma volume, heart rate and D(L)CO. NO(x) concentrations were not significantly increased in the patients. NO(x) correlated with portal pressure and haemodynamic indicators of vasodilatation, but not with exhaled NO concentrations.
  
  
  CONCLUSIONS
  In patients with moderate cirrhosis, exhaled NO is normal. Circulating NO(x) do not seem to reflect pulmonary and systemic NO release, but NO(x) seems to reflect systemic and splanchnic haemodynamic changes in cirrhosis.
authors: Department of Clinical Physiology and Nuclear Medicine, Hvidovre Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors: Pia
authors: P
authors: Afzelius
authors: Nassim
authors: N
authors: Bazeghi
authors: Peter
authors: P
authors: Bie
authors: Flemming
authors: F
authors: Bendtsen
authors: Jørgen
authors: J
authors: Vestbo
authors: Søren
authors: S
authors: Møller
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001944:Breath Tests; D016022:Case-Control Studies; D003718:Denmark; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D006975:Hypertension, Portal / Q000097:blood* / Q000209:etiology / Q000503:physiopathology; D008103:Liver Cirrhosis / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood*; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000097:blood*; D017082:Portal Pressure; D011653:Pulmonary Diffusing Capacity; D012084:Renin-Angiotensin System; D012129:Respiratory Function Tests; D013152:Splanchnic Circulation; D016683:Supine Position; D014664:Vasodilation
chemical_list: D015415:Biomarkers; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide