| First Author | Stein O | Year | 1997 |
| Journal | Proc Natl Acad Sci U S A | Volume | 94 |
| Issue | 18 | Pages | 9820-4 |
| PubMed ID | 9275209 | Mgi Jnum | J:42816 |
| Mgi Id | MGI:1096304 | Doi | 10.1073/pnas.94.18.9820 |
| Citation | Stein O, et al. (1997) Delayed loss of cholesterol from a localized lipoprotein depot in apolipoprotein A-I-deficient mice. Proc Natl Acad Sci U S A 94(18):9820-4 |
| abstractText | The anti-atherogenic role of high density lipoprotein is well known even though the mechanism has not been established. In this study, we have used a novel model system to test whether removal of lipoprotein cholesterol from a localized depot will be affected by apolipoprotein A-I (apo A-I) deficiency. We compared the egress of cholesterol injected in the form of cationized low density lipoprotein into the rectus femoris muscle of apo A-I K-O and control mice. When the injected lipoprotein had been labeled with [3H]cholesterol, the t1/2 of labeled cholesterol loss from the muscle was about 4 days in controls and more than 7 days in apo A-I K-O mice. The loss of cholesterol mass had an initial slow (about 4 days) and a later more rapid component; after day 4, the disappearance curves for apo A-I K-O and controls began to diverge, and by day 7, the loss of injected cholesterol was significantly slower in apo A-I K-O than in controls. The injected lipoprotein cholesterol is about 70% in esterified form and undergoes hydrolysis, which by day 4 was similar in control and apo A-I K-O mice. The efflux potential of serum from control and apo A-I K-O mice was studied using media containing 2% native or delipidated serum. A significantly lower efflux of [3H]cholesterol from macrophages was found with native and delipidated serum from apo A-I K-O mice. In conclusion, these findings show that lack of apo A-I results in a delay in cholesterol loss from a localized depot in vivo and from macrophages in culture. These results provide support for the thesis that anti-atherogenicity of high density lipoprotein is related in part to its role in cholesterol removal. |
