ECMR knockout (KO) (ECMR−/−) mice were kindly provided by Drs. Iris Z. Jaffe and Katelee Barrett Mueller from Tufts University Medical Center who also contributed to the design of this investigation.33 In these mice, Exon 5 and Exon 6 of the MR gene are flanked by loxP sites via homologous recombination (MRf/f), as previously described.33 ECMR KO was generated by crossing MRf/f mice with Cad-Cre+ mice.33 , 34 MRf/f Cad-Cre littermates were used as controls.35 (link) All animal procedures were performed in accordance with the Animal Use and Care Committee at the University of Missouri-Columbia, the Subcommittee for Animal Safety at the Harry S. Truman Memorial Veterans’ Hospital and National Institutes of Health Guide for the Care and Use of Laboratory Animals. Groups of four-week-old female mice were fed a WD36 (link) consisting of high fat (46%) and a high carbohydrate component as constituted with sucrose (17.5%) and high fructose corn syrup (17.5%) for 16 weeks. Parallel groups of age-matched female controls (ECMR+/+) were fed regular control diet (CD) for the same period of time.
For detailed description of procedures, see methods in the online-only Data Supplement.