Abstract
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 stress.
Methods::
Wistar rats (n=9) weighing 250-300 mg were operated under a microscope and two of the epischeral veins were cauterized. 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). In vivo chemiluminiscence was performed with a Johnson Foundation photon counter. TRAP was measured by chemiluminiscence. Nitrite concentration and TBARS were measured spectrophotometrically
Results::
A 35% of decrease in chemiluminescence at early stages (7-30 days) and a 22% of increased at later stage (45- 60 days) were observed in the glaucomatous eyes. 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). 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). Nitrite concentration was 18.0 ± 0.9 µM para los ojos control fue de 9.5 ± 0.8 µM p < 0.01).
Conclusions::
Reactive oxygen species were increased in glaucoma, this could be evidenced by the increased in the chemiluminescence and lipid peroxidation. Organ chemiluminiscence seems to afford a non invasive assay that integratively measures the rate of formation of excited species. The increased chemiluminescence observed at later stage could be due to a decrease in the antioxidant defenses. The decrease in the antioxidant levels may be a consecuence of an increase in oxidative processes
Keywords: oxidation/oxidative or free radical damage • optic nerve • antioxidants