HDL levels are inversely related to the risk of developing atherosclerosis. In serum, paraoxonase (PON) is associated with HDL, and was shown to inhibit LDL oxidation. Whether PON also protects HDL from oxidation is unknown, and was determined in the present study. In humans, we found serum HDL PON activity and HDL susceptibility to oxidation to be inversely correlated (r2 = 0.77, n = 15). Supp...

This study revealed and characterised the presence of the antioxidant enzymes paraoxonase (PON) type 1 (PON-1, extracellular) and type 2 (PON-2, intracellular) in boar semen. To evaluate PON-1, an entire ejaculate from each of ten boars was collected and the seminal plasma was harvested after double centrifugation (1,500g for 10 min). Seminal plasma was analysed for concentration as well as enz...

Human serum paraoxonase (PON 1) exists in 2 major polymorphic forms (Q and R), which differ in the amino acid at position 191 (glutamine and arginine, respectively). These PON allozymes hydrolyze organophosphates and aromatic esters, and both also protect LDL from copper ion-induced oxidation. We have compared purified serum PONs of both forms and evaluated their effects on LDL oxidation, in re...

References Advantages of FTTx and PON Components of a PON System PON Installation PON Specifications PON Measurement Parameters PON Troubleshooting Selecting the Right Testing Instrument Conclusion Testing fiber-to-the-X (FTTx) networks that include passive optical network (PON) architectures presents unique challenges to service providers. During installation, the network must meet certain sta...

Genetic variations of paraoxonase (PON) correlate with HDL cholesterol and apolipoprotein A-I (apoA-I), suggesting antiatherogenic properties. Atherosclerosis occurs naturally in humans and rabbits but not in mice. We compared variations of PON arylesterase activity (PON AEase, phenylacetate substrate) in humans, rabbits, and mice. In humans and rabbits, >95% of PON AEase is HDL associated. In ...

OBJECTIVE Paraoxonase (PON) exhibits esterase activity (PON-AREase) and lactonase activity (PON-HCTLase), which prevent LDL oxidation and detoxify homocysteine thiolactone (HCTL). The role of HCTL and PON-HCTLase as a risk factor for the microvascular complication in diabetic retinopathy at the level of vitreous has not been investigated. RESEARCH DESIGN AND METHODS Undiluted vitreous from pa...

BACKGROUND & OBJECTIVES The enzyme paraoxonase (PON), an antioxidant enzyme that has both arylesterase and thiolactonase activity, is well studied in cardiovascular diseases. Although a few studies have shown altered PON activity in ocular diseases such as age-related macular degeneration and diabetic retinopathy, but the tissue-wise expression of PON in its three gene forms has not been studie...

In the absence of insulin, regular physical activity facilitates the glucose entry into the cell via affecting several signaling pathways. Moreover, regular exercise improves the lipid profile and increases the paraoxonase-1 (PON-1) activity. PON-1 interacts with High-density lipoprotein (HDL) and, in the presence of calcium, hydrolyzes free radicals, prevents low-density lipoprotein (LDL) oxid...

In Japan, FTTH users will soon overtake ADSL users [1], [2]. This means that the main technology of broadband access systems has moved from metallic systems such as ADSL to optical systems. PON (Passive Optical Network) is the most popular technology for optical broadband access systems because PON can provide optical access services at low cost by sharing transmission equipment [3]. However, P...

BACKGROUND Cardiovascular risk largely depends on diet, antioxidant status, and gene polymorphisms. Low-fat meat (CM) and walnut-enriched meat (WM) products may exert potential beneficial health effects with respect to conventional meat products. OBJECTIVE To compare the effects of consuming WM vs CM on reduced and oxidized glutathione, lipoperoxides, α- and γ-tocopherol levels, and paraoxona...