title: Inhibition of epidermal growth factor binding to Swiss 3T3 cells by human platelet release-products.
abstract: Human platelet ionophore release-products (IRP) inhibit the binding of 125I-labelled epidermal growth factor (125I-EGF) to its receptors on Swiss 3T3 cells. The inhibition appears to be caused by platelet-derived growth factor (PDGF) in the IRP and results from a decrease in the apparent affinity of cellular receptors for 125I-EGF. However, our results indicate that PDGF does not bind directly to EGF receptors, since (1) PDGF does not down-regulate EGF receptors; (2) the PDGF-mediated inhibition of 125I-EGF binding is temperature-dependent; (3) cells which possess EGF receptors but lack PDGF receptors do not exhibit a PDGF-mediated inhibition of 125I-EGF binding.
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004848:Epithelium; D066246:ErbB Receptors; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D051381:Rats; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*
chemical_list: D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface; D004815:Epidermal Growth Factor; D066246:ErbB Receptors