The expression of NADPH oxidase in cultured mouse embryos, which were exposed to H2O2 of 30 min and then treated with pioglitazone, with untreated embryos as a control. A, PCR results of NADPH oxidase RNA in mouse embryos; B, relative expression of NADPH oxidase RNA normalized with the internal marker GAPDH. Different letters in the same picture mean the significant difference between the treatments (P < 0.05).