title: High affinity binding sites for epidermal growth factor (EGF) in renal membranes.
abstract: The kidney produces large quantities of EGF but the role of the kidney in binding and degradation of EGF is unknown. We studied 125I-EGF binding and degradation by highly purified cortical luminal and cortical basolateral membranes of rabbit renal cortex, and by medullary plasma membranes. Specific binding for 125I-EGF was found for the first time in cortical basolateral and medullary plasma membranes (60-80% of total binding) but not in cortical luminal membranes. There was little degradation (less than 4%) of EGF by any of the membranes. Scatchard analysis of 125I-EGF binding by cortical basolateral membranes revealed two distinct classes of binding sites: high and low affinity. The existence of high specific binding sites in cortical basolateral and in medullary plasma membranes suggests a physiologic role of EGF in the kidney.
authors.affiliation: Department of Medicine, University of Illinois Hospital, Chicago.
authors.forename: E
authors.initials: E
authors.lastname: Sack
authors.forename: Z
authors.initials: Z
authors.lastname: Talor
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D007672:Kidney Cortex / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism*; D007700:Kinetics; D011817:Rabbits
chemical_list: D004815:Epidermal Growth Factor; D066246:ErbB Receptors