Effect of atherogenic diet on reverse cholesterol transport in vivo in atherosclerosis susceptible (C57BL/6) and resistant (C3H) mice

Mice susceptible (C57BL/6) or resistant (C3H) to atherosclerosis induced by a high cholesterol-cholate containing diet (A-diet) were used to study rev erse cholesterol transport (RCT) in vivo as measured by loss of cholesterol from a depot created by injection of cationized LDL into the rectus femori s muscle. Plasma total and HDL-cholesterol (HDL-C), total and HDL phospholi pid (HDL-PL) levels in chow fed C3H male and female mice were higher than i n C57BL/6 mice. After one month on A-diet, plasma cholesterol more than dou bled in both strains and genders. The decrease in HDL-C and HDL-PL was twic e as great in C57BL/6 as in C3H female mice, while in male C3H mice there w as no decrease. The loss of exogenous cholesterol mass (ECM) after injectio n of cationized LDL was more rapid in C3H than in C57BL/6 mice. In chow fed mice, ECM retained in muscle on day 12 was 37% in C57BL/6 and 20% in C3H f emales; in males it was 39% and 18% in C57BL/6 and C3H, respectively. On A- diet, 76% were retained in C57BL/6 and 28% in C3H females; these values wer e 59% and 28% in C57BL/6 and C3H males. Thus, the slow clearance of ECM (wh ich represents RCT) in C57BL/6 mice on A-diet, that could be related to a m arked decrease of HDL-PL, might contribute towards their susceptibility to atherosclerosis. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved .