Zucker obese fa fa zo and lean zl rats

All animal procedures used in this study were approved by the Harry S. Truman Veterans Memorial Hospital (HSTVMH) Subcommittee for Animal Safety and University of Missouri IACUC before commencing. All animals were cared for in accordance with the Guidelines for the Care and Use of Laboratory Animals (National Institutes of Health publication 85-23). Zucker obese (fa/fa) (ZO) and lean (ZL) rats (Charles River Laboratories) were used in this study. Rats were maintained on ad libitum food and water and housed singly at the HSTVMH animal housing facility under standard laboratory conditions (room temperature: 21– 22°C; light and dark cycles: 12h). Food intake was monitored by placing a pre-weighed amount of food in the cage and determining the weight of leftover food after 24 hrs. At 8-weeks of age, rapamycin pellets designed to deliver Rap at a concentration of 750µg/kg/day for 21 days (from Innovative Research of America, Inc, Sarasota, FL) or placebo pellets were placed surgically under the skin behind the shoulder blades under brief isoflurane anesthesia and this procedure was repeated 3 times to achieve a 12-week treatment. Body composition was determined using the EchoMRI 4in1/1100 as described previously (18 (link)). Hearts were harvested at time of sacrifice as described before (18 (link)), flash frozen in liquid nitrogen, and stored at -80°C for future use.