Paraoxonase-1 (PON1) (EC or EC is a high-density lipoprotein (HDL)-associated serum enzyme whose primary physiological role is to protect low-density lipoproteins (LDLs) from oxidative modifications. PON1 can also hydrolyze organophosphorus (OP) compounds, including commonly used insecticides, and its name derives from one of its most commonly used in vitro substrates—paraoxon. More recently, in addition to its role in lipid metabolism and, hence, in cardiovascular disease and arteriosclerosis, PON1 has also been shown to be involved in the metabolism of lactones and cyclic carbonates. Early studies of enzymatic activity in serum indicated a bimodal or trimodal distribution in Caucasian populations. Two main polymorphisms in the coding region, as well as five in the 5' regulating region, have been characterized. The Q192R polymorphism determines the catalytic efficiency of hydrolysis of some substrates, and certain promoter polymorphisms, in particular C-108T, contribute to the level of expression of PON1. Recently, additional polymorphisms in the coding region, 5' regulatory region, and PON1 introns have been reported.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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