title: Cooperation of HDL Receptor and Hepatic Lipase in the Selective Uptake of HDL(2)-CE by Rat Hepatic Sinusoidal Cells.
abstract: The recombined (3)H-CE-HDL(2)(rHDL(2)) keeps the biological activities of the native HDL(2). After rat hepatic sinusoidal cells were incubated with rHDL(2) at 37 degrees for 3 h (normal group), the cell-endocytic cpm was 995-/+147(mean-/+s, n=2). After the cells were further incubated for 2 h, the cell-release TCA-precipitable cpm and the TCA-supernatant cpm were 78-/+32 and 12-/+9 respectively. These values were 339-/+62, 19-/+11 and 9-/+5 respectively in the acetylimidazole-modified group, and 542-/+78, 34-/+14 and 9-/+8 respectively in the heparin-pretreated group. Our results suggested that: (1) Rat hepatic sinusoidal cells internalize HDL(2) and take up HDL(2)-CE by its HDL receptor, and HDL(3) was secreted out of the cells by retroendocytosis. (2) Hepatic lipase (HL) induces directly the selective uptake of HDL(2)-CE by the cells. (3) There is cooperation between the HDL receptor and HL in the selective uptake of HDL(2)-CE by the cells.
authors.affiliation: Department of Biochemistry, School of Pharmacy, Shanghai Medical University, Shanghai 200032, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wei
authors.forename: Man-Ping
authors.initials: MP
authors.lastname: Wu
authors.forename: Pei-Fang
authors.initials: PF
authors.lastname: Chen
authors.forename: Mei-Zhen
authors.initials: MZ
authors.lastname: Mei
authors.forename: Xin-Jian
authors.initials: XJ
authors.lastname: Gao