Studies have been conducted to evaluate the possible "protective" role of PON, and especially the influence of the Arg-->Gln 192 polymorphism, in coronary artery disease.
Ex vivo, the PON1 polymorphisms are important in determining the capacity of HDL to protect LDL against oxidative modification in vitro and this may explain the relationship between the PON1 alleles and coronary heart disease in case-control studies.
PON1 may also confer protection against coronary artery disease by destroying pro-inflammatory oxidized lipids present in oxidized low-density lipoproteins (LDLs).
The PON1 polymorphisms are important in determining the capacity of high-density lipoprotein (HDL) to protect low-density lipoprotein (LDL) against oxidative modification in vitro and this may explain the relationship between the PON1 alleles and coronary heart disease in case-control studies.
Paraoxonase (PON) is a high-density lipoprotein (HDL)-associated enzyme involved in preventing the oxidation of low-density lipoprotein (LDL), and an association has been shown between two genetic polymorphisms in PON1 and the risk of coronary artery disease.
The frequency of the R allele of PON1, which has been related to the risk of coronary heart disease, was significantly higher in Belfast (0.33) than in Toulouse (0.24; chi2 = 7.229, P = 0.0072).
The Q/R192 variants of PON1 are not associated with severity, progression or regression of coronary atherosclerosis, plasma lipid levels, clinical events, or response to treatment with fluvastatin.
A common polymorphism of the PON1 gene, the PON1-192 genetic polymorphism, modulates PON1 activity and has been related in some studies to coronary heart disease.
It is a very important observation, however, because genetic influences are not likely to be confounded by other factors linked with both coronary heart disease and diminished paraoxonase 1 activity.
Relation between butyrylcholinesterase K variant, paraoxonase 1 (PON1) Q and R and apolipoprotein E epsilon 4 genes in early-onset coronary artery disease.
Finally, we suggest directions for the future that might elucidate the role of the PON genetic polymorphisms in this potentially important function of PON(s) and the role in coronary heart disease and other related diseases.