Figure 2.
Dose-response studies. Cells were pretreated with CuE concentrations ranging from 10−6 to 10−10 M for 3 h and then exposed to 5 mM MPP+. Cytotoxicity was measured using the colorimetric LDH release assay. The absorbance value obtained for the untreated control was subtracted from all other values, as described in Materials and Methods. Administration of CuE alone induced minimal cellular death. Values are the average of 6 samples from 4 independent experiments for a total of 24 measurements. Data are expressed as means ± S.E.M. n = 4. ◊◊◊ P < 0.001 versus MPP+.