Metabolic Effects of Cholesterol-Rich Diet in Mice

This study was approved by the German Animal Studies Committee of Schleswig-Holstein and was conducted in compliance with international guidelines. Two groups of female mice, with genotypes Cyp17a1(d/d) × ApoE(d/d) and ApoE(d/d), were studied. The symbol “d” stands for deletion and is similar to KO or “−”. From the age of 10 weeks, mice were fed either a standard chow diet (chow) or a Western-type diet (WTD) containing 0.2% cholesterol and 21.2% fat (TD.88137; ssniff Spezialdiäten GmbH, Soest, Germany) for 8 weeks. The mice were maintained under controlled conditions of temperature (23 °C), humidity (40–60%), and lighting (12 h/12 h light/dark cycle). After 8 weeks of diet-feeding, the mice were euthanized using an overdose of isoflurane inhalation, followed by cervical dislocation, and then perfused with phosphate-buffered saline, pH 7.4 (Lonza, Cologne, Germany). Blood samples were collected to study the lipid profiles of the mice, as described previously [16 (link)]. The body mass and visceral fat mass were determined as previously described [16 (link)]. Finally, the caeca of the mice containing feces were collected, and tail biopsies were obtained for re-genotyping. All the samples collected were stored at −80 °C until further analysis.