Oxidative stress markers in a glaucoma model in rat.

FERREIRA S; LERNER F; BRUNZINI R; EVELSON P; LLESUY S

Estados Unidos

Congreso; ARVO; 2007

The Association for Research in vision and ophthalmology

Purpose: The aim of this work was to performance a glaucoma model in rat to evaluate the relationship between the development of glaucoma and oxidative damage. Methods: Wistar rats weighing 250-300 mg were operated under a microscope by cauterized two of the epischeral veins. The animals were anesthetized with ketamine 50 mg/ kg and xylazine 0,5 mg/ kg. In order to assess the occurrence of oxidative stress the following markers were evaluated: in vivo chemiluminescence, the total antioxidant capacity (TRAP), nitrite concentration and markers of lipid peroxidation (TBARS). Results: In vitreous humor of glaucomatous eyes TRAP value was 92 ± 8 µM Trolox (control value 219 ± 24 µM Trolox p < 0.01). In the aqueous humor of glaucomatous eyes TRAP value was 142 ± 7 µM Trolox. (control value 192 ± 4 µM Trolox p < 0.01). In optic nerve head TBARS value 4.2 ± 0.5 nmoles/ mg potein (control value 1.9 ± 0.1 nmoles/ mg protein p < 0.001). Nitrite concentration was 18.0 ± 0.9 M in glaucoma and for control eyes 9.5 ± 0,8 mM p < 0.01). A decrease in chemiluminescence at early stages (7-30) and an increased at later stage (45- 60 days) were observed. Conclusion: Reactive oxygen species were increased in glaucoma, this could be evidenced by the increased in the chemiluminescence and lipid peroxidation. The decrease in the antioxidant levels may be a consecuence of an increase in oxidative process. •The increased chemiluminescence observed at later stage could be due to a decrease in the antioxidant defenses. CR: None Support: University of Buenos Aires (Grant number: B124)