Figure 3: Metal-metal interactions in Zn-induced neurotoxicity. A: Effects of various metals on Zn neurotoxicity in GT1-7 cells Various metal ion solutions containing 50 μM of CuCl2 (Cu2+), FeCl2 (Fe2+), FeCl3 (Fe3+), MnCl2 (Mn2+), LiCl3 (Li+), PbCl2 (Pb2+), GdCl3 (Gd3+), AlCl3 (Al3+), or 2 mM of CaCl2 (Ca2+), or MgCl2 (Mg2+) were administered to GT1-7 cells prior to treatment with ZnCl2 (50 μM). After 24 h, cell viability was measured using the WST-1 method. For the compensation of endogenous toxicity of the metal, the difference was calculated between cell viability with the metal alone and viability with Zn and metal, and was described as the relative viability. Data are presented as mean ± S.E.M., n=6. * p<0.01. B: Effects of calcium overload The viability of GT1-7 cells was compared among control (culture media containing 1.8 mM of Ca2+), Zn2+ (50 μM of ZnCl2 was pre-administered), Ca2+ (5 mM of CaCl2 was pre-administered), and Zn2++ Ca2+ (50μM of ZnCl2 and 5 mM of CaCl2 were co-administered) treatments. Both Zn2+ and Ca2+ caused marked death of GT1-7 cells, but co-administration of Zn2+ and Ca2+ protected GT1-7 cells. Data are presented as mean ± S.E.M., n=6. * p<0.01.