title: Differences in the uptake of transferrin bound 239Pu and 59Fe into multicellular spheroids of hepatocytes from adult male rats.
abstract: Hepatocytes were cultured as monolayers and multicellular spheroids, respectively. The uptake of both transferrin-bound metals, iron and plutonium, differed significantly between these two culture systems. The uptake into the multicellular spheroids for plutonium was about 30 times greater, and for iron about 4 times greater, than in monolayer-cultured hepatocytes, which is not a consequence of proliferation and/or de-differentiation of the hepatocytes in the multicellular spheroid culture system. A comparison of the iron and plutonium uptake showed that plutonium was delivered to the cells to an 8-fold greater extent than iron if the hepatocytes were cultured as spheroids. Additionally, the binding of plutonium was not inhibited by preincubation of the spheroids with the iron-transferrin complex. Therefore, we propose that there are two different binding sites for iron and plutonium on hepatocyte membranes.
mesh_terms: D000818:Animals; D002449:Cell Aggregation; D002478:Cells, Cultured; D007501:Iron / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D011005:Plutonium / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D014168:Transferrin / Q000378:metabolism*
chemical_list: D014168:Transferrin; D011005:Plutonium; D007501:Iron