BACKGROUND & AIMS: Vascular adhesion protein 1 (VAP-1) is an endothelial glycoprotein that supports adhesion of lymphocytes to hepatic endothelium and has sequence homology with semicarbazide-sensitive amine oxidases (SSAOs). We investigated whether soluble VAP-1 (sVAP-1) displays SSAO activity and thereby accounts for increased monoamine oxidase activity in the serum of patients with liver diseases. METHODS: sVAP-1 concentration and SSAO activity were measured in peripheral, hepatic, and portal blood and in bile from patients with liver disease and in peripheral blood of control subjects, using enzyme-linked immunosorbent assay and enzymatic assays. RESULTS: sVAP-1 concentration (mean [+/-SE], 143. 67 [34.97-92.67] ng/mL) and SSAO activity (18.8 [12.0-24.6] nmol. mL(-1). h(-1)) were significantly increased in chronic liver diseases compared with healthy controls (87.1 [53.5-127] ng/mL [P<0.001] and 10.7 [6.5-12.7] nmol. mL(-1) x h(-1) [P<0.05]) but not in massive necrosis caused by paracetamol poisoning (109 [80.3-140] ng/mL and 8.9 [5.7-12.3] nmol. mL(-1) x h(-1)). sVAP-1 correlated with serum transaminase and bilirubin but not with creatinine. In 5 paired samples, sVAP-1 concentration was higher in hepatic (median, 113 [range, 53-122]) than in portal vein (102 [42-109]; 2P<0.05), and was not detected in bile. There was a highly significant correlation between serum sVAP-1 and SSAO activity in normal subjects, patients with acute liver failure, and those with chronic liver disease (r = 0.895; P<0.001). When serum was depleted of sVAP-1 by immunoaffinity chromatography, SSAO activity was eliminated. CONCLUSIONS: sVAP-1 levels are increased in chronic liver disease, and sVAP-1 is likely derived from the liver. Serum sVAP-1 displays SSAO activity and accounts for most of the monoamine oxidase activity in human serum.
BACKGROUND & AIMS:Vascular adhesion protein 1 (VAP-1) is an endothelial glycoprotein that supports adhesion of lymphocytes to hepatic endothelium and has sequence homology with semicarbazide-sensitive amine oxidases (SSAOs). We investigated whether soluble VAP-1 (sVAP-1) displays SSAO activity and thereby accounts for increased monoamine oxidase activity in the serum of patients with liver diseases. METHODS: sVAP-1 concentration and SSAO activity were measured in peripheral, hepatic, and portal blood and in bile from patients with liver disease and in peripheral blood of control subjects, using enzyme-linked immunosorbent assay and enzymatic assays. RESULTS: sVAP-1 concentration (mean [+/-SE], 143. 67 [34.97-92.67] ng/mL) and SSAO activity (18.8 [12.0-24.6] nmol. mL(-1). h(-1)) were significantly increased in chronic liver diseases compared with healthy controls (87.1 [53.5-127] ng/mL [P<0.001] and 10.7 [6.5-12.7] nmol. mL(-1) x h(-1) [P<0.05]) but not in massive necrosis caused by paracetamolpoisoning (109 [80.3-140] ng/mL and 8.9 [5.7-12.3] nmol. mL(-1) x h(-1)). sVAP-1 correlated with serum transaminase and bilirubin but not with creatinine. In 5 paired samples, sVAP-1 concentration was higher in hepatic (median, 113 [range, 53-122]) than in portal vein (102 [42-109]; 2P<0.05), and was not detected in bile. There was a highly significant correlation between serum sVAP-1 and SSAO activity in normal subjects, patients with acute liver failure, and those with chronic liver disease (r = 0.895; P<0.001). When serum was depleted of sVAP-1 by immunoaffinity chromatography, SSAO activity was eliminated. CONCLUSIONS: sVAP-1 levels are increased in chronic liver disease, and sVAP-1 is likely derived from the liver. Serum sVAP-1 displays SSAO activity and accounts for most of the monoamine oxidase activity in human serum.
Authors: Marko Salmi; Craig Stolen; Pekka Jousilahti; Gennady G Yegutkin; Päivi Tapanainen; Tuula Janatuinen; Mikael Knip; Sirpa Jalkanen; Veikko Salomaa Journal: Am J Pathol Date: 2002-12 Impact factor: 4.307
Authors: A Abella; S García-Vicente; N Viguerie; A Ros-Baró; M Camps; M Palacín; A Zorzano; L Marti Journal: Diabetologia Date: 2004-02-13 Impact factor: 10.122