Theses and Dissertations

Issuing Body

Mississippi State University


Chambers, Janice E.

Committee Member

Crow, John A.

Committee Member

Wills, Robert W.

Date of Degree


Document Type

Graduate Thesis - Open Access


Veterinary Medical Science

Degree Name

Master of Science (M.S.)


College of Veterinary Medicine


Veterinary Medical Science Program


Paraoxonase-1 (PON1) is a high density lipoprotein (HDL)-associated enzyme displaying esterase and lactonase activity. PON1 hydrolyzes the oxons of several organophosphorous insecticides (e.g. paraoxon, diazoxon and chlorpyrifos-oxon) and metabolizes lipid peroxides of low density lipoproteins (LDL) and HDL. As such, PON1 plays a relevant role in determining susceptibility of organophosphate toxicity and cardiovascular disease. The objective of this study was to determine associations of PON1 status (i.e. genotype and activity levels) with atherosclerosis (ATH) in individuals from the Southeastern United States. An additional objective was to determine whether PON1 genotype and/or PON1 activity levels influence the capacity of PON1 to metabolize chlorpyrifos-oxon (CPO) at a relatively low concentration. Data indicated increasing PON1 activity assessed by hydrolysis of phenyl acetate is associated with decreased odds of ATH. Furthermore, neither PON1 genotype nor PON1 activity levels influence capacity of PON1 to metabolize CPO at a relatively low concentration.