THE EFFECT OF AURINTRICARBOXYLIC ACID, AN ENDONUCLEASE INHIBITOR, ON ISCHEMIA-REPERFUSION DAMAGE IN RAT RETINA

Apoptosis is a form of cell death distinct from necrosis showing disti nctive morphologic features and may require energy. It is under variou s control mechanisms and may involve an endonuclease, which cleavages genomic DNA in the internucleosomal linker regions. Previously, we rep orted that ischemic/reperfusion injury to rat retina induced endonucle ase mediated apoptosis of retinal neurons. In this study, we examined the effect of aurintricarboxylic acid (ATA), an endonuclease inhibitor , on ischemia/reperfusion damage in rat retina in our established rat model. A single intraperitoneal injection of ATA at 2 mg/kg given imme diately after 60 minutes of ischemia to the retina showed no observabl e effect. At 10 mg/kg, there was notable beneficial effect morphologic ally but not morphometrically. ATA at 100 mg/kg showed significant eff ect both morphologically and morphometrically. This observation is con sistent with the hypothesis that endonuclease mediated apoptosis may b e involved in retinal cell loss after ischemia/reperfusion insult.