title: Metabolism of Oxidized High Density Lipoprotein-2(ox-HDL(2)) in Rat Hepatic Sinusoidal Cells.
abstract: Incubation of rat hepatic sinusoidal cells with FITC-HDL(2), FITC-ox-HDL(2) and [(3)H]CE-HDL(2)(rHDL(2)), ox-rHDL(2) showed that binding of FITC-HDL(2) to the cells was competitive to ox-HDL(2), but not to HDL(2). The cell-endocytic fluorescence strength (FS) of FITC-HDL(2) and radioactivity of ox-rHDL(2) were 45.5% of that of FITC-HDL(2) and 61.4% of that of rHDL(2), respectively. Endocytic FS and radioactivity were mainly in TCA-precipitable and supernatant part, respectively. The cell-released FS and radioactivity were 67.7% and 10.9% of the cell-endocytic FS and the radioactivity, respectively, and both of them were mainly TCA-precipitable. These results suggest that: (1) There is probably an ox-HDL receptor on the surface of rat hepatic sinusoidal cells, which is different from HDL receptor. (2) The metabolic behaviour of ox-rHDL(2) in the cells is similar to HDL(2). Both of them do not take a lysosomal pathway. Apoproteins and CE components dissociate from endocytic lipoprotein in the cells. After the cells have taken up most of CE, the residual CE recombines with apolipoprotein to form a lipoprotein and is released from the cells by retroendocytosis. (3) Oxidative modification of HDL(2) weakens its ability to cholesterol reverse transport.
authors.affiliation: Department of Biochemistry, School of Pharmacy, Shanghai Medical University, Shanghai 200032, China. qqzhuang@shmu.edu.cn
authors.forename: An
authors.initials: A
authors.lastname: Cheng
authors.forename: Man-Ping
authors.initials: MP
authors.lastname: Wu
authors.forename: Bin
authors.initials: B
authors.lastname: Lou
authors.forename: Pei-Fang
authors.initials: PF
authors.lastname: Chen
authors.forename: Xiao-Qi
authors.initials: XQ
authors.lastname: Yang
authors.forename: Mei-Zhen
authors.initials: MZ
authors.lastname: Mei