Increased urinary F(2)-isoprostanes levels in the patients with Alzheimer's disease.

Isoprostanes, novel markers of oxidative injury, are generated by the free radical-mediated peroxidation of arachidonic acid (AA). They are thought to be important in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD). Using gas chromatography-mass spectrometry (GC-MS), we investigated the alteration of urinary F(2)-isoprostanes in AD patients compared to that of healthy subjects. Our results show that the levels of urinary F(2)-isoprostanes, sum of the prostaglandin F(2 alpha) isomer; prostaglandin F(2 alpha) (PGF(2 alpha)), prostaglandin F(2 beta) (PGF(2 beta)), and 8-isoprostaglandin F(2 alpha) (8-isoPGF(2 alpha)), significantly increased in AD patients (P < 0.05). The concentration of urinary 8-isoPGF(2 alpha), one of the biomarkers of oxidative stress, was not significantly different between 34 AD patients and 20 age-matched controls (P > 0.05). The PGF(2 alpha), formed by endoperoxide reductase from PGH(2), was significantly increased in AD patients, when compared with the levels of the normal controls (P < 0.05). The PGF(2 alpha), an enzymatic product of arachidonic acid, may affect the pathogenesis of AD. In addition, urinary F(2)-isoprostanes can play an important role as a biomarker in AD.