The Neuroprotective Effect of alpha-phenyl-N-tert-butyl-nitrone (PBN) in the Argon Laser Induced Retinal Ischemia

ABSTRACT

PURPOSE: We examined the ability of alpha-phenyl-tert-butyl-nitrone (PBN), an electron spin trapper, to determine the neuroprotective effect in the argon laser induced ischemic rat retina model. METHODS: After ischemic condition of rat retina was induced by argon green laser, PBN was given intraperitoneally at 50 or 100 mg/kg and normal saline was injected to control group. After 24 hours, 48 hours, and 7 days, the neuroprotective effect of PBN was examined by electroretinogram (ERG) and after 7 days, the enucleation of eyes was performed and histologic findings were compared by light microscopy and transmission electron microscopy. RESULTS: We found relatively reduced amplitude of ERG wave in the PBN injected group but not so greatly reduced as in normal saline control group. The retinal ganglion cell (RGC) layer and the number of RGCs were affected by acute ischemic changes but in the group of PBN treatment, the cell membrane was well preserved and vecuoles formation, cytoplasmic destructions, nuclear chromatin condensation were reduced. CONCLUSIONS: Systemic administration of PBN can ameliorate an argon laser induced retinal ischemia. Further investigations are necessary to decide effective dose without toxicity and to find more convenient methods of administrations.