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Abstract #6191 Published in IGR 2-2
F(2) isoprostanes, potential specific markers of oxidative damage in human retina
Nourooz-Zadeh J; Pereira POphthalmic Research 2000; 32: 133-137
F(2) isoprostanes (F(2)-IPs) are a series of prostaglandin-F(2)(PGF (2))-like compounds produced during peroxidation of arachidonic acid (AA) by a mechanism independent of the cyclo-oxygenase. Of these, 8-epi-PGF(2α) has proved a reliable marker of oxidative stress in studies both in vitro and in vivo. Human retinas (n = 28) were obtained from healthy donors (aged 15-59 years) and analyzed for the content of free (non-esterified) as well as total (sum of free and esterified) F (2)-IPs. Retina tissue was homogenized, total lipids were partitioned with ethyl acetate and isoprostanes were isolated by chromatography on an NH(2) cartridge. After formation of pentafluorobenzyl ester and trimethylsilyl derivatives, F(2)-IPs were analyzed by negative ion-chemical ionisation mass spectrometry using tetradeuterated PGF(2α) as the internal standard. Analysis of retina samples revealed the presence of measurable amounts of esterified 8-epi-PGF(2α) (mean: 81.71 μg/g AA; range: 3.29-187.89 μg/g AA) but not free F(2)-IPs. There was no correlation between age and content of 8-epi-PGF(2α). Detection of esterified F(2)-IPs in human retina provides the first direct evidence for free-radical-catalyzed peroxidation of AA in retinal tissue. Analysis of F(2)-IPs should provide new opportunities for studying the implications of oxidative injury in various diseases of retina, including diabetic retinopathy and age-related macular degeneration.
Dr. J. Nourooz-Zadeh, Department of Medicine, Division of Clinical Pharmacology and Toxicology, University College London, London, UK
Classification:
11.4 Prostaglandins (Part of: 11 Medical treatment)