Related Experiment Video
Updated: Aug 13, 2026

Novel Whole-tissue Quantitative Assay of Nitric Oxide Levels in Drosophila Neuroinflammatory Response
Published on: December 5, 2013
[From organophosphate compound toxicity to atherosclerosis: role of paraoxonase 1]
T Dantoine1, J Debord, L Merle
1Département de gérontologie clinique, CHU de Limoges, 2, avenue Martin-Luther-King, 87042, Limoges, France. tdantoine@wanadoo.fr <tdantoine@wanadoo.fr>
Purpose:
Paraoxonase 1 is an ubiquitous human serum and tissue esterase known to hydrolyse organophosphorous compounds. It seems to be implicated in various vascular diseases.
Current Knowledge And Key Points:
Recently paraoxonase has been located on the surface of High Density Lipoproteins (HDL) which has directed studies towards its involvement in atherosclerosis. An antioxidant effect has been suggested from its structure rich in reducing amino acids (cysteine), which was confirmed on low density lipoproteins (LDL) first in vitro and then in vivo. Paraoxonase 1 hydrolyses an arachidonic acid derivative found on the surface of oxidised LDL known to participate in the essential initial step of atherogenesis. Clinically paraoxonase 1 activity is low when pathological vascular ageing occurs early (myocardial infarction) and when cardiovascular risk is high (diabetes mellitus, chronic renal failure, analphalipoproteinemia).
Future Prospects And Projects:
The genetic polymorphism of this enzyme is one of the determinants of serum paraoxonase 1 activity variations. It could explain sensitivity differences in chronic organophosphate intoxications and has been suspected as a risk factor of vascular injury. A decrease of this enzyme activity with ageing could play a part in the high prevalence of cardiovascular diseases in the aged.
Related Concept Videos
Peroxisomes
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Toxic Reactions: Overview
Toxicity falls into two primary categories: local and systemic.
Local toxicity appears at the exposure site, such as protein denaturation caused by caustic substances.
In contrast, systemic toxicity requires the toxic agent's absorption and distribution,...
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Anticholinesterase Agents: Poisoning and Treatment
Irreversible agents form a strong bond with the cholinesterase enzyme, making it inactive. The breakdown of the phosphorylated enzyme is slower than the...
Phase I Oxidative Reactions: Overview

