Abstract
Purpose: :
To investigate the effect of hyperbaric oxygen (HBO) chamber treatment of anterior ischemic optic neuropathy (AION) in mice.
Methods: :
AION was induced in one eye of 55 mice by laser activation of intravenously injected rose-Bengal. The fellow eye was untreated and served as an internal control. Twenty-eight mice were exposed to 100% oxygen (2 Atm) for 90 minutes immediately following injury and daily thereafter for up to 14 days. Retinas were harvested at 1, 3 and 21 days after AION induction, and mRNA levels of SOD-1, HO-1, eNOS and Thy-1 were analyzed using quantitative real-time polymerase chain reaction. Histological analysis of retinal sections was performed as well.
Results: :
At 1 day following AION induction, expression of the oxidative-stress-induced gene, SOD-1, decreased to 82% of control levels. At 3 days, expression of the ischemia-related genes, HO-1 and eNOS, decreased to 74% of control levels. At 21 days, HO-1 rose to 2.2-fold of control levels, whereas eNOS decreased to 48% of controls. Treatment with HBO prevented the decrease in SOD-1 expression on 1 day and was associated with an increase in HO-1 and eNOS on day 3. At 21 days after treatment, SOD-1 decreased whereas eNOS increased. HO-1 increased to a lower level than without treatment. The HBO-treated animals did not show retinal ganglion cell loss or a decrease in Thy-1 expression compared to the untreated mice.
Conclusions: :
HBO treatment after AION induction in mice influences the expression levels of oxidative-stress and ischemia-related genes and may exert a neuroprotective effect in this setting.
Keywords: retina • gene/expression