title: Partial characterisation and subcellular distribution patterns of endothelin-1, -2 and -3 binding sites in human liver.
abstract: For the first time, endothelin-1, -2 and -3 (ET-1, -2, -3) binding sites were characterized in human liver and shown to differ significantly in their respective dissociation constants and densities. In addition, subcellular distribution patterns of these binding sites in biochemically analysed fractions obtained after differential centrifugation were shown to be heterogeneous. Thus, the bulk of ET-1 and ET-3 binding sites seemed to be present in plasma membranes, although their partial presence in a compartment sedimenting together with the endoplasmic reticulum cannot be excluded. In contrast, a major proportion of the ET-2 binding sites appeared to be associated with a compartment sedimenting together with mitochondria, suggesting a special accumulation of ET-2 binding sites in human liver. A significant portion of ET-1, -2 and -3 binding sites seems to be localized also in lysosomes, presumably indicating their participation in the internalisation process.
authors.affiliation: Pharma Division, Preclinical Research, F. Hoffman-La Roche Ltd, Basel, Switzerland.
authors.forename: B M
authors.initials: BM
authors.lastname: Löffler
authors.forename: B
authors.initials: B
authors.lastname: Kalina
authors.forename: H
authors.initials: H
authors.lastname: Kunze
mesh_terms: D001665:Binding Sites; D002458:Cell Fractionation; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D016232:Endothelins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure; D008247:Lysosomes / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017466:Receptors, Endothelin
chemical_list: D016232:Endothelins; D011956:Receptors, Cell Surface; D017466:Receptors, Endothelin