title: Platelet cytosolic calcium concentration in patients with liver cirrhosis. Relationship with hepatic and systemic hemodynamics.
abstract: OBJECTIVE
  Due to structural and functional similarities between platelets and vascular smooth muscle cells, platelet cytosolic calcium concentration ([Ca2+]i) has been suggested to be a useful tool to study regulatory mechanisms of peripheral vascular tone. The aim of the present study was to investigate platelet [Ca2+]i in patients with cirrhosis and whether this parameter is related with the systemic and splanchnic vasodilatation found in these patients.
  
  
  METHODS
  Seventeen patients with cirrhosis and eight age- and sex-matched controls were studied. Mean arterial pressure, cardiac output, femoral blood flow and basal and thrombin-stimulated platelet [Ca2+]i were measured. Cardiac output (thermal dilution), azygos blood flow, hepatic venous pressure gradient and hepatic blood flow were also measured in patients with cirrhosis.
  
  
  RESULTS
  Patients with cirrhosis had severe portal hypertension and a significantly higher cardiac output and femoral blood flow and a significantly lower systemic and femoral vascular resistance than controls. Patients with cirrhosis had a lower basal platelet [Ca2+]i than normal subjects. However, there was no relationship between platelet [Ca2+]i and any of the hemodynamic parameters that evaluate systemic or splanchnic vasodilatation.
  
  
  CONCLUSIONS
  This study shows that cirrhotic patients with portal hypertension have a significant reduction in platelet basal [Ca2+]i. The lack of correlation between platelet [Ca2+]i and hepatic and systemic hemodynamics does not support the use of platelet [Ca2+]i as a model to study mechanisms involved in the pathophysiology of the hyperdynamic circulation associated to portal hypertension.
authors.affiliation: Nephrology Department, Hospital Clìnic i Provincial, University of Barcelona, Spain.
authors.forename: J C
authors.initials: JC
authors.lastname: Bandi
authors.forename: E
authors.initials: E
authors.lastname: Poch
authors.forename: J C
authors.initials: JC
authors.lastname: García-Pagán
authors.forename: A
authors.initials: A
authors.lastname: Luca
authors.forename: W
authors.initials: W
authors.lastname: Jiménez
authors.forename: A
authors.initials: A
authors.lastname: Escorsell
authors.forename: J
authors.initials: J
authors.lastname: Rodés
mesh_terms: D001792:Blood Platelets / Q000737:chemistry*; D002118:Calcium / Q000032:analysis*; D003600:Cytosol / Q000737:chemistry*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006975:Hypertension, Portal / Q000503:physiopathology; D008102:Liver Circulation / Q000502:physiology; D008103:Liver Cirrhosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D014655:Vascular Resistance; D014664:Vasodilation
chemical_list: D002118:Calcium