Original Contribution SERUM PARAOXONASE AND ARYLESTERASE ACTIVITY OF PON1 IN ACUTE CORONARY SYNDROME

Serum paraoxonase (PON 1) is a HDL-associated enzyme that is believed to be a protective factor against cardiovascular disease, inhibiting oxidation of LDL complexes. PON1 is Ca ²+ dependent hydrolase with two activities: lactonase and 3-esterase, which are probably based on the properties of the enzyme to protect against oxidative changes in both LDL and HDL and thereby reduces the risk of cardiovascular disease. Objective: To determine serum paraoxonase and arylesterase activities of PON1 in patients with acute coronary syndrome and to compared them with those in healthy subjects. Material and methods: Present study includes 42 patients with acute coronary syndrome, 36 with acute myocardial infarction with ST-segment elevation (STEMI), 6 with unstable angina (NAP) and 26 healthy subjects. Results: Serum paraoxonase activity of PON 1 in acute myocardial infarction and unstable angina was significantly lower compared with healthy controls (p<0.005, p<0.008). There was a weak trend (R=0.273) of positive correlation between serum paraoxonase activity of PON1 and -cholesterol in patients (p=0.080) and lack of that in controls (p=0.89). There was a weak trend (R=0.199) of negative correlation between serum paraoxonase activity of PON1 and b-cholesterol in patients (p=0.213). Normalized levels of paraoxonase and arylesterase activities of PON1 compared to levels of HDL-C were significantly lower in the group with acute myocardial infarction and unstable angina compared to controls (p<0.001, p=0.026). PON-activity of PON1 in subjects with hypertension, with three-branch and multi-branch coronary artery disease and those patients who experienced a previous cardiovascular events was significantly lower (p=0.03, p=0.07, p=0.018). Conclusion: Serum paraoxonase and arylesterase activities in STEMI and NAP were significantly lower compared with controls.