[Isoprostanes--new possibility of the oxidative stress estimation]

Isoprostanes are new markers of the oxidative stress estimation. They are chemically stable prostaglandin isomers that are produced by free radical-catalyzed peroxidation of polyunsaturated fatty acids, among other things arachidonic acid. Isoprostanes, in contrast to prostaglandins, are synthesized in cell membrane or in lipoproteins phospholipid, and are released into circulation by the action of phospholipases. Isoprostanes circulate in plasma, and are uptaken and metabolised by the tissues. Isoprostane metabolites and their non-metabolised forms are excreted in urine. Isoprostanes, especially 8-iPF2alpha-III, possess potent biological activity. They cause vasoconstriction, induce mitogenesis and may modulate platelet functions. Clinical data indicate an increased level of isoprostanes biosynthesis in certain diseases related to oxidative stress. These compounds have longer half life than other of lipid peroxides, and methods for measurement of isoprostanes are more sensitive and specific than methods for measurement of other peroxidation products.