ANTIOXIDANT EFFECT OF ß-ESTRADIOL ON CEREBELLAR GRANULE CELLS IRRADIATED IN VITRO.

PAGOTTO, RML; ZIEHER LM; ZORRILLA ZUBILETE, M.A; GUELMAN LR

New Orléans, LA, USA

Congreso; 33rd. Annual Meeting de la Society for Neuroscience (SFN); 2003

Society for Neuroscience (SFN)

Ionizing radiations are thought to induce developing Central Nervous System (CNS) damage mainly through the generation of reactive oxygen species (ROS). Agents capable of preventing neuronal injury by scavenging ROS or by decreasing their production have been subject of study in several CNS diseases in which oxidative stress is involved. The aim of the present work was to test if ß-estradiol, an agent whose antioxidant activity has been reported in recent studies, was effective in preventing cell death through an oxidative mechanism in an CNS in vitro irradiation model. Cultures of cerebellar granule cells of 8-days-old rats were exposed to 30 cGy of gamma radiation (60Co) within 2 hs after seeding. 1 µM of ß-estradiol (final concentration) was added 30 min prior irradiation. Cell viability and ROS levels were evaluated after 48 hs in vitro. Irradiated cultures show a significative decrease in viable cell number (49.2 ± 2.3 % respect to control) and a significative increase in their ROS level (192.5 ± 12.2 % respect to control). ß-estradiol pretreatment of irradiated cultures was effective in preventing not only cell death (66.8 ± 3.6 % respect to control, + 36 % respect to irradiated cultures) but also radiation-induced ROS increase (124.1 ± 16 % respect to control, - 36 % respect to irradiated cultures). This data suggest that ROS scavenging activity could underlie ß-estradiol neuroprotective mechanism, leading to the increase in cell viabilty.