LIVER ENDOTHELIUM AND NOT HEPATOCYTES OR KUPFFER CELLS HAVE TRANSFERRIN RECEPTORS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 63  (2) , 270-276
Abstract
Using a visual probe, consisting of latex minibeads covalently linked to transferrin (TF), in rat liver cell suspensions transferrin receptors were found to be limited to endothelial cells. Neither hepatocytes nor Kupffer cells contained an appreciable number of TF receptors. Specificity of this reaction was demonstrated by preincubation with nonderivatized TF, which inhibited the binding. This was further confirmed by fractionation of liver cell suspensions on metrizamide gradients. The uptake of either the visual probe or 125I-labeled TF was again limited to the endothelium-rich fraction. Transferrin bound to endothelial membrane was internalized at 37.degree. C, but not at 4.degree. C, via a coated pit system. Again, hepatocytes and Kupffer cells did not internalize the probe. Fe may be 1st taken up by liver endothelium and then transmitted to parenchymal cells. The generally unappreciated role of endothelium in the transport across the tissue-blood barrier is emphasized.