NES metabolism in plasma and brain of female mice after NES administration at 10 and 200 µg/mouse. NES metabolites were measured by GC/MS/MS. Steroid concentrations are measured in plasma after administration of NES at 200 µg (A) and 10 µg (B) and in brain at 200 µg (C) and 10 µg (D) at different postadministration time points. Steroid concentrations are expressed as ng/mL ± SEM or ng/g ± SEM.