title: Paraoxonase and arylesterase activities in patients with cardiac syndrome X, and their relationship with oxidative stress markers.
abstract: OBJECTIVE
  Paraoxonase-1 is a high-density lipoprotein-associated enzyme with three activities, which are paraoxonase, arylesterase and dyazoxonase. Paraoxonase-1 was shown to decrease in patients with cardiovascular diseases. We aimed to examine serum paraoxonase and arylesterase activities, and their relation with oxidative stress markers such as lipid hydroperoxide and total antioxidant status in patients with cardiac syndrome X.
  
  
  METHODS
  Forty-one consecutive patients with cardiac syndrome X (CSX group), 33 consecutive patients without cardiac syndrome X (non-cardiac syndrome X group) and 20 healthy volunteers as control group were taken into the study. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. Lipid hydroperoxide levels were measured by ferrous oxidation with xylenol orange assay. Total antioxidant status was determined using an automated measurement method.
  
  
  RESULTS
  Basal paraoxonase, salt-stimulated paraoxonase and arylesterase activities were significantly lower in patients with cardiac syndrome X than those of the non-cardiac syndrome X and control groups (P<0.001, for both). Moreover, lipid hydroperoxide was found at high level, and total antioxidant status was found at low level in patients with cardiac syndrome X than control and non-cardiac syndrome X groups (P<0.001, for all). In patients with cardiac syndrome X, in multiple linear regression analysis, both paraoxonase and arylesterase activities were independently correlated with lipid hydroperoxide levels (P=0.001, P=0.003, respectively), and also arylesterase activity was independently correlated with magnitude of ST depression (P=0.002).
  
  
  CONCLUSIONS
  Reduced paraoxonase and arylesterase activities and total antioxidant status levels and enhanced lipid hydroperoxide levels in patients with cardiac syndrome X might indicate increased oxidative stress that can play a role in pathogenesis of cardiac syndrome X.
authors.affiliation: Department of Cardiology, Faculty of Medicine, Harran University, Sanliurfa, Turkey. drmugur@yahoo.com
authors.forename: Mustafa
authors.initials: M
authors.lastname: Gur
authors.forename: Ali
authors.initials: A
authors.lastname: Yildiz
authors.forename: Recep
authors.initials: R
authors.lastname: Demirbag
authors.forename: Remzi
authors.initials: R
authors.lastname: Yilmaz
authors.forename: Mehmet
authors.initials: M
authors.lastname: Aslan
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Ozdogru
authors.forename: Ozcan
authors.initials: O
authors.lastname: Erel
mesh_terms: D000975:Antioxidants / Q000032:analysis; D043303:Aryldialkylphosphatase / Q000097:blood*; D015415:Biomarkers; D002265:Carboxylic Ester Hydrolases / Q000097:blood*; D017023:Coronary Angiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D017566:Microvascular Angina / Q000097:blood* / Q000000981:diagnostic imaging; D008875:Middle Aged; D018384:Oxidative Stress
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase; D043303:Aryldialkylphosphatase