First Author | Johnson J | Year | 2005 |
Journal | Circulation | Volume | 111 |
Issue | 11 | Pages | 1422-30 |
PubMed ID | 15781753 | Mgi Jnum | J:108994 |
Mgi Id | MGI:3625566 | Doi | 10.1161/01.CIR.0000158435.98035.8D |
Citation | Johnson J, et al. (2005) Plaque rupture after short periods of fat feeding in the apolipoprotein E-knockout mouse: model characterization and effects of pravastatin treatment. Circulation 111(11):1422-30 |
abstractText | BACKGROUND: These studies examined the early time course of plaque development and destabilization in the brachiocephalic artery of the apolipoprotein E-knockout mouse, the effects of pravastatin thereon, and the effects of pravastatin on established unstable plaques. METHODS AND RESULTS: Male apolipoprotein E-knockout mice were fed a high-fat, cholesterol-enriched diet from the age of 8 weeks. Animals were euthanized at 1-week intervals between 4 and 9 weeks of fat feeding. Acutely ruptured plaques were observed in the brachiocephalic arteries of 3% of animals up to and including 7 weeks of fat feeding but in 62% of animals after 8 weeks, which suggests that there is a sharp increase in the number of plaque ruptures at 8 weeks. These acute plaque ruptures then appear to heal and form buried fibrous caps; after 9 weeks of fat feeding, mice had 1.05+/-0.15 buried fibrous caps at a single site in the brachiocephalic artery. Pravastatin (40 mg/kg of body weight per day for 9 weeks; resultant plasma concentration 16+/-4 nmol/L) had no effect on plasma cholesterol concentration in fat-fed apolipoprotein E-knockout mice but reduced the number of buried fibrous caps by 43% (P<0.0001). In longer-term experiments, the delay of pravastatin treatment until unstable plaques had developed reduced the incidence of acute plaque rupture by 36% (P<0.0001). CONCLUSIONS: Plaque rupture occurs at high frequency in the brachiocephalic arteries of male apolipoprotein E-knockout mice after 8 weeks of fat feeding. Pravastatin treatment inhibits early plaque rupture and is also effective when begun after unstable plaques have developed. |