[Oxidative damage and photoreceptor cell apoptosis in contusion injury of the rabbit retina].

ABSTRACT

OBJECTIVE: To study the mechanism of retina injury and photoreceptor apoptosis after contusion as well as their triggering factor. METHODS: The rabbit retina was injured by a 3 J energy contusion caused by a free falling iron bar hitting the cornea. The morphologic changes of the retina were observed by light and electron microscopes. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) technique was used to assess apoptosis. The amount of the malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the retina were assayed and analyzed statistically. RESULTS: Apoptosis of photoreceptors was present in retina contusion caused by a 3 J energy injury. After contusion, the MDA level increased gradually. The activity of SOD increased reflectively at first, then decreased markedly 3 days after the contusion, which was parallel with the appearance of apoptotic photoreceptors. CONCLUSIONS: Apoptosis is an important mechanism of retina contusion. Free oxygen radicals are the important triggering factors for the apoptosis of photoreceptors in the retina contusion of the rabbits.