Acinar heterogeneity of the epidermal growth factor receptor in the liver of male rats.
Epidermal growth factor is cleared from the circulation by the liver, forming a very steep portal-to-central sequestration gradient. It was unknown whether this was due to the position within the liver acinus or whether it was due to functional differences in the hepatocytes. Experiments were undertaken to elucidate the lobular distribution and heterogeneity of the epidermal growth factor receptor in rat liver. Immunocytochemistry showed a predominantly higher staining density over periportal localized hepatocytes. Receptor binding studies with isolated, cultured hepatocytes, enriched in periportal or perivenous located cells, were performed. Our data revealed high- and low-affinity binding sites with a kd of 26 pM and 0.87 nM, respectively, for periportal hepatocytes. The high-affinity receptors were restricted to the periportal hepatocytes only, whereas the number of low-affinity receptors showed a 3 to 4-fold concentration gradient between both cell populations.
Institute for Clinical Pharmacology, University of Berne, Switzerland.
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U
Marti
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Gebhardt
D000818:Animals; D001665:Binding Sites; D066246:ErbB Receptors / Q000032:analysis*; D007124:Immunoenzyme Techniques; D008099:Liver / Q000098:blood supply / Q000378:metabolism*; D008297:Male; D010477:Perfusion; D011505:Protein-Tyrosine Kinases; D051381:Rats; D011919:Rats, Inbred Strains
D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases