Net en

All procedures were approved by the Ohio State University Institutional Animal Care and Use Committee and the Stanford University Administrative Panel on Laboratory Animal Care. As indicated, 6– to 8–wk-old C57BL/6J (wild-type) and NOD-scid IL-2Rg^null (NSG) female mice were purchased from Jackson Laboratory (Bar Harbor, ME). As indicated, mice were s.c. injected for five consecutive days with 100 μl of PBS alone or a PBS solution containing 1 mg of NET-EN (Sigma-Aldrich, Laramie, WY) (prepared by glass-to-glass homogenization and sonication), whereas other mice were s.c. administered a single dose of 1 mg of DMPA (Depo-Provera) or 2 mg of methylprednisolone (MePRDL) (Depo-Medrol) (both Pfizer, New York, NY). Where indicated, cells collected by vaginal lavage were stained with crystal violet to identify wild-type and NSG mice in the estrus stage of the estrous cycle (26 ). Also as indicated, mice were euthanized 24 h after the fifth NET-EN treatment, and the serum was sent to the Endocrine Technologies Support Core at the Oregon National Primate Research Center to quantify norethisterone (NET) levels by liquid chromatography–tandem triple quadrupole mass spectrometry (27 (link)).