Fig. 8.

Impact of the RXR antagonist on p,p′-DDE and o,p′-DDE–induced on caspase-3 activity (a) and LDH release (b) at 7 DIV hippocampal cultures. Primary hippocampal cultures were treated with p,p′-DDE or o,p′-DDE (10, 100 μM) for 6 h. The RXR antagonist HX 531 (0.1 μM) was added into the culture media approximately 45–60 min before DDE was added. The results were normalized to the absorbency in vehicle-treated cells and expressed as a percentage of control. Each bar represents the mean of three to four independent experiments ± SEM. The number of replicates in each experiment ranged from 5 to 8. *p < 0.05, **p < 0.01, ***p < 0.001 versus control cultures, ^# p < 0.05, ^## p < 0.01, and ^### p < 0.001 versus the cultures exposed to DDE