title: Paraoxonase phenotype distribution in a healthy Iranian population.
abstract: Human serum paraoxonase (PON1) is a high-density lipoprotein-associated esterase that protects against organophosphate neurotoxicity, and is proposed to play a role in lipid metabolism and the onset of cardiovascular disease. In the present study, paraoxonase activities and phenotype distribution in serum of 132 healthy Iranian individuals aged 17-68 years were assessed using dual substrate method. In the study population, a wide interindividual variability (up to 15-fold) of paraoxonase activity was found. The mean of basal, salt-stimulated paraoxonase and arylesterase activities were 81.8 +/- 57 U/ml, 153.1 +/- 117.5 U/ml and 80.7 +/- 12.8 kU/l, respectively. The ratio of salt-stimulated paraoxonase activity to arylesterase activity was used for definition of phenotypes. Based on the observed ratios, three distinct phenotypes AA (low activity), AB (intermediate activity) and BB (high activity) were determined. The PON1 ratio varied from 0.5 to 6.8. The paraoxonase phenotype frequencies were approximately 48% (AA), 41% (AB) and 11% (BB). In this work, serum triglycerides had significant positive correlation (r = 0.334, P < 0.05) with paraoxonase activity, whereas high-density lipoprotein did not. No significant decrease in paraoxonase activity by smoking was observed. Age and sex had no influences on PON1 activities. In conclusion, the distribution of paraoxonase phenotypes in this Iranian population was trimodal and comparable to that of Caucasians from North America; however, overall enzyme activity was lower than that reported for Caucasians.
authors.affiliation: Institute of Biochemistry and Biophysics, Tehran University, Tehran, Iran.
authors.forename: Farideh
authors.initials: F
authors.lastname: Sepahvand
authors.forename: Massoumeh
authors.initials: M
authors.lastname: Shafiei
authors.forename: Seyed Mahmood
authors.initials: SM
authors.lastname: Ghaffari
authors.forename: Parvaneh
authors.initials: P
authors.lastname: Rahimi-Moghaddam
authors.forename: Massoud
authors.initials: M
authors.lastname: Mahmoudian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D043303:Aryldialkylphosphatase / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D005260:Female; D005828:Genetics, Population; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012907:Smoking / Q000378:metabolism; D014280:Triglycerides / Q000097:blood
chemical_list: D014280:Triglycerides; D002784:Cholesterol; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase; D043303:Aryldialkylphosphatase