title: Hyperlipidemia and atherosclerotic lesion development in LDL receptor-deficient mice fed defined semipurified diets with and without cholate.
abstract: Past studies of atherosclerosis in mice have used chow-based diets supplemented with cholesterol, lipid, and sodium cholate to overcome species resistance to lesion formation. Similar diets have been routinely used in studies with LDL receptor-deficient (LDLR(-/-)) mice. The nonphysiological nature and potential toxicity of cholate-containing diets have led to speculation that atherogenesis in these mice may not accurately reflect the human disease process. We have designed a semipurified AIN-76A-based diet that can be fed in powdered, pelleted, or liquid form and manipulated for the precise evaluation of diet-genetic interactions in murine atherosclerosis. LDLR(-/-) mice were randomly assigned among 4 diets (n=6/diet) as follows: 1, control, 10% kcal lipid; 2, high fat (40% kcal), moderate cholesterol (0.5% by weight); 3, high fat, high cholesterol (1.25% by weight); and 4, high fat, high cholesterol, and 0.5% (wt/wt) sodium cholate. Fasting serum cholesterol was increased in all cholesterol-supplemented mice compared with controls after 6 or 12 weeks of feeding (P<0.01). The total area of oil red O-stained atherosclerotic lesions was determined from digitally scanned photographs. In contrast to the control group, all mice in cholesterol-supplemented dietary groups 2 to 4 had lesions involving 7.01% to 12.79% area of the thoracic and abdominal aorta at 12 weeks (P<0.002, for each group versus control). The distribution pattern of atherosclerotic lesions was highly reproducible and comparable. The histological features of lesions in mice fed cholate-free or cholate-containing diets were similar. This study shows that sodium cholate is not necessary for the formation of atherosclerosis in LDLR(-/-) mice and that precisely defined semipurified diets are a valuable tool for the examination of diet-gene interactions.
authors.affiliation: Vascular Research Division, Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Lichtman
authors.forename: S K
authors.initials: SK
authors.lastname: Clinton
authors.forename: K
authors.initials: K
authors.lastname: Iiyama
authors.forename: P W
authors.initials: PW
authors.lastname: Connelly
authors.forename: P
authors.initials: P
authors.lastname: Libby
authors.forename: M I
authors.initials: MI
authors.lastname: Cybulsky
mesh_terms: D000821:Animal Feed; D000818:Animals; D001011:Aorta / Q000473:pathology; D001161:Arteriosclerosis / Q000209:etiology*; D001835:Body Weight; D020355:Cholates / Q000008:administration & dosage*; D004032:Diet; D006949:Hyperlipidemias / Q000209:etiology*; D008055:Lipids / Q000097:blood; D008099:Liver / Q000033:anatomy & histology / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D011973:Receptors, LDL / Q000172:deficiency*
chemical_list: D020355:Cholates; D008055:Lipids; D011973:Receptors, LDL