Figure 3

AT2R mediates zinc toxicity as well as the toxicity-potentiating effect of angiotensin II. A) Western blots for AT1R and AT2R in astrocytic, mixed, and near-pure neuronal cultures showing that both neurons and astrocytes express substantial levels of both receptors. B) LDH release (mean ± SEM, n = 6) in cortical cell cultures after 15 min exposure to 300 μM zinc alone or with addition of the selective AT1R inhibitor losartan (500 nM) or selective AT2R inhibitor PD123319 (1 μM) (*p < 0.05 versus zinc alone; two-tailed t-test). C) LDH release (mean ± SEM, n = 5) in cortical cell cultures after 15 min exposure to 300 μM zinc alone, zinc plus 1 μM angiotensin II, zinc plus angiotensin II and losartan, or zinc plus angiotensin II and PD123319 (*p < 0.05 for differences between indicated values; two-tailed t-test). D) LDH release (mean ± SEM, n = 4) in cortical cell cultures after 15 min exposure to 300 μM zinc or zinc plus CGP42112 (0.5 μM – 10 μM). CGP42112 potentiated zinc-triggered cell death in a concentration-dependent manner (*p < 0.05 versus zinc alone; two-tailed t-test). E) LDH release (mean ± SEM, n = 9) in near-pure neuronal cultures after 15 min exposure to 300 μM zinc or zinc plus 1 μM CGP42112 (*p < 0.05 versus zinc alone; two-tailed t-test). F) LDH release (mean ± SEM, n = 6) in astrocytic cultures after 15 min exposure to 300 μM zinc or zinc plus the indicated concentrations of CGP42112. G) LDH release (mean ± SEM, n = 10) in cortical cell cultures after 15 min exposure to 300 μM zinc alone, zinc plus 1 μM CGP42112, zinc plus CGP42112 and losartan, or zinc plus CGP42112 and PD123319 (*p < 0.05 for differences between indicated values; two-tailed t-test).