Western Diet and Phthalate Effects on Atherosclerosis

Apoe^−/− mice, which were on the C57BL/6 genetic background, were generated from breeding pairs purchased from the Jackson Laboratory, Bar Harbor, ME. At 6 weeks of age, female mice were switched onto a Western diet containing 21% fat, 0.15% cholesterol, 34.1% sucrose, 19.5% casein, and 15% starch (TD88137, Harlan Laboratories) and maintained on the diet for 12 weeks. Female mice were chosen because they are more susceptible to atherosclerosis than male counterparts [21 (link)] and also they were used in our previous studies [22 (link)-25 (link)]. One group of mice received bis-(2-ethylhexyl) phthalate (Sigma) during Western diet consumption, and the control group received no phthalate. The phthalates were administered in drinking water at a daily dosage of 100 mg/kg of body weight for each mouse, as reported [26 (link)]. This dose has been shown to be effective in inducing estrogenic effects in mice [26 (link)]. All procedures were carried out in accordance with current National Institutes of Health guidelines and approved by the Institutional Animal Care and Use Committee.