title: Uptake of fractionated heparin by two types of scavenger receptors in isolated rat Kupffer cells.
abstract: The uptake of fractionated heparin was examined in the absence and presence of anionic proteins such as acetylated low density lipoprotein (Ac-LDL) and maleylated bovine serum albumin (Mal-BSA) to characterize the scavenger receptors involved in the uptake of fractionated heparin in isolated rat Kupffer cells. The uptake of fractionated heparin was completely inhibited by Ac-LDL and dextran sulfate, but only partially by Mal-BSA. Kinetic analysis revealed that the binding capacity (Bmax) of the Mal-BSA-insensitive receptor was significantly larger than that of the Mal-BSA-sensitive one, though their dissociation constants (Kd) were not significantly different. The apparent internalization rate constant (kint,app) was significantly larger for the Mal-BSA-sensitive receptor than for the Mal-BSA-insensitive one. Thus, the scavenger receptors involved in the uptake of fractionated heparin in Kupffer cells can be classified into two types, in terms of sensitivity to Mal-BSA. Mal-BSA-sensitive receptors have been characterized in macrophages and classified as class A. The Mal-BSA-sensitive one found in Kupffer cells in this study may belong to class A, while the Mal-BSA-insensitive one has been little characterized elsewhere.
authors.affiliation: Department of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Nagoya City University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: H
authors.initials: H
authors.lastname: Yuasa
authors.forename: J
authors.initials: J
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D002417:Cattle; D006493:Heparin / Q000378:metabolism*; D007700:Kinetics; D007728:Kupffer Cells / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D051381:Rats; D017208:Rats, Wistar; D011971:Receptors, Immunologic / Q000378:metabolism*; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B
chemical_list: D008565:Membrane Proteins; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B; D006493:Heparin