Propagation processes and lipid hydroperoxide formation

Radicals (R ) formed from conjugated lipid dienes react spontaneously with oxygen to form peroxy radicals  

Peroxy radicals are either quenched by antioxidants or react with adjacent polyunsaturated lipids by abstraction of hydrogen, thus forming lipid hydroperoxides (ROOH)  

The measurement of lipid hydroperoxides in biological samples is frequently used as an index of lipid peroxidation. In practice such measurements are complicated by the lability of these compounds in the presence of metal ions, and thiols and by the metabolism of hydroperoxides by peroxidases such as glutathione peroxidase and the glutathione 5-transferases. 

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