Lower serum paraoxonase-1 activity in type 2 diabetic patients correlates with nitrated apolipoprotein A-I levels.

摘要

Paraoxonase 1 (PON-1) an enzyme located mainly in HDL, is largely responsible for HDL-antioxidant activity. Low PON-1 activity may contribute to the increased atherosclerosis found in type 2 diabetic patients by reducing the ability of HDL to retard LDL oxidation . Nitrosative stress is also increased in diabetic patients and nitrotyrosine levels are increased in plasma from diabetic patients. We previously showed that the nitrotyrosine-apoA-I is higher in individuals with type 2 diabetes. Very recently it has been shown that PON-1 in type 2 diabetics tends to dissociate from HDL, which could explain hi part the lower activity found. We hypothesized that increased circulating levels of nitrated apoA-I in type 2 diabetic patients correlate with decreased PON-1 activity.