C57BL/6N female mice (6–7 weeks of age) were purchased from Charles River Laboratories (Raleigh, NC). Half of the mice were adx, and half received sham adrenalectomy operations (sham); surgeries were performed at Charles River Laboratories prior to arrival at the U.S. EPA. Once at the U.S. EPA’s animal facilities (accredited by the Association for Assessment and Accreditation of Laboratory Animal Care), animals were housed in groups of six in polycarbonate cages with hardwood chip bedding (Beta chip; Northeaster Products, Warrensburg, NY). They were provided a 12-h light:dark cycle (light, 0600–1800 h; dark, 1800–0600 h), maintained at 22.3 ± 1.1C and 50 ± 10% humidity, and given ad libitum access to both food (5P00 Prolab RMH 3000; PMI Nutrition International, Richmond, IN) and water. Animals were acclimated for 1 day before dosing began. All procedures employed in this study were approved in advance by the Institutional Animal Care and Use Committee of the National Health and Environmental Effects Research Laboratory, U.S. EPA.