title: Plasma substance P levels in patients with liver cirrhosis: relationship to systemic and portal hemodynamics.
abstract: OBJECTIVE
  Nitric oxide has been proposed as being responsible for the hyperdynamic circulation observed in portal hypertensive states. Substance P, a neuropeptide partly cleared by liver, induces vasodilation through the activation of the endothelial nitric oxide pathway. This study investigated the plasma levels of substance P in cirrhotic patients and the relationship of these levels to systemic and portal hemodynamics.
  
  
  METHODS
  Sixty-four patients with cirrhosis and 53 healthy controls had blood samples taken for determining plasma values of substance P by ELISA. Systemic and portal hemodynamics were measured on the same day of blood sampling using a Swan-Ganz catheterization and thermodilution technique.
  
  
  RESULTS
  Plasma levels of substance P were higher in cirrhotic patients than in healthy controls (45.7 +/- 2.0 vs 32.9 +/- 1.0 pg/ml, p < 0.001) and directly correlated with Child-Pugh's score (r = 0.52, p < 0.0001). Compared with compensated cirrhotic patients, decompensated cirrhotic patients had higher plasma levels of substance P accompanied by a lower systemic vascular resistance and higher hepatic venous pressure gradient. There was no significant correlation between plasma levels of substance P and systemic vascular resistance and hepatic venous pressure gradient. In addition, no significant difference in plasma levels of substance P was observed between cirrhotic patients with and cirrhotic patients without a hepatic venous pressure gradient > 12 mm Hg or between patients with and patients without large esophageal varices.
  
  
  CONCLUSIONS
  Plasma levels of substance P are increased in patients with cirrhosis and may contribute to the pathogenesis and/or maintenance of hyperdynamic circulation in decompensated patients. The severity of cirrhosis is more important than portal hypertension and the severity of esophageal varices for the development of increased plasma substance P levels.
authors.affiliation: Department of Medicine, Veterans General Hospital-Taipei, Taiwan, Republic of China.
authors.forename: F Y
authors.initials: FY
authors.lastname: Lee
authors.forename: H C
authors.initials: HC
authors.lastname: Lin
authors.forename: Y T
authors.initials: YT
authors.lastname: Tsai
authors.forename: F Y
authors.initials: FY
authors.lastname: Chang
authors.forename: R H
authors.initials: RH
authors.lastname: Lu
authors.forename: M C
authors.initials: MC
authors.lastname: Hou
authors.forename: C P
authors.initials: CP
authors.lastname: Li
authors.forename: C J
authors.initials: CJ
authors.lastname: Chu
authors.forename: S S
authors.initials: SS
authors.lastname: Wang
authors.forename: S D
authors.initials: SD
authors.lastname: Lee
mesh_terms: D005260:Female; D006439:Hemodynamics; D006801:Humans; D007124:Immunoenzyme Techniques; D008103:Liver Cirrhosis / Q000097:blood* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011168:Portal System / Q000503:physiopathology*; D013373:Substance P / Q000097:blood*; D013815:Thermodilution / Q000295:instrumentation / Q000379:methods
chemical_list: D013373:Substance P