ارتباط بین فعالیت آنزیم پارااکسوناز/ آریل استراز با سطوح لیپیدی سرم

Background and Aim: Human serum paraoxonase (PON) / aryl esterase (ARE) is synthesized by the liver and its roles are hydrolysis of organophosphate compounds in mammals and resistance against atherosclerosis. This enzyme has tree model phenotypes-distribution, including AA (homozygous with low activity), AB (heterozygous with Average activity), or BB (homozygous with high activity). This study was aimed to measure the level of PON/ARE activity and determine the relationship between activity of this enzyme and serum lipid levels & non- lipid indices in 25-50 year-old healthy men. Materials and Methods: Our research was a sectional and observational study. Fifty healthy men from Tarbiat Moddares University were volunteered for this research. PNO activity was measured by a spectrophotometric method using 1 ml serum; adding 1 mmol Tris/HCL buffer including 2 mmol/L calcium chloride and 5.5 mmol/L HCL. Paranitrophenol production was measured at 405 nm wave length. ARE was determined by adding serum to 20 ml buffer including 1 mmol/L calcium chloride and 1 mmol/L phenyl acetate. Phenotype distribution was estimated by two substrates method. The correlation between PON/ARE activities and lipid & non-lipid indices were evaluated by Pearson correlation analysis. We used 2-tailed Pvalues. The P<0.05 was accepted as the level of significance. Results: The average activities of PON and ARE were 89.14±40.62 and 100.15±36.16 U/L, respectively. This means that our participants had lower enzyme activity and all of them classified as AA phenotype. There were no significant correlations between PON/ARE activity and demographic characteristics (age, body mass index, waist to hip ratio or blood pressure). In addition, there were no significant correlations between PON/ARE activity and lipid indices (triglyceride, total cholesterol, LDL & HDL). However, LDL/PON ratio had a significant relationship with HDL/LDL ratio(r=-0.45, P<0.002), HDL/total cholesterol ratio (r=-0.37, P<0.01), total cholesterol concentration (r=0.34, P<0.02), and LDL concentration (r=0.46,P<0.001). Conclusion: Existence of weak correlation between serum PON/ARE activities and lipid indices along with low PON activity in studied group suggest that PON/ARE enzyme activities are under influence of genetic and racial factors.