Uptake of 67Cu by isolated human trophoblast cells.
The isolated human trophoblast was used as a system to analyze the effects of different physiological ligands on cellular uptake of copper. The results show that the uptake of copper by these cells follows a similar pattern for the ligands tested (histidine, albumin and ceruloplasmin) as that for copper chloride. The process follows a typical hyperbolic curve at 37 degrees C. The initial phase of uptake follows a linear pattern during 30 min at 37 degrees C and at least 60 min at 4 degrees C from which the uptake rate is calculated. However, a significant decrease in the uptake rate is observed for albumin. The effect of histidine on stimulating copper transport is observed in the presence of serum, a phenomenon which is considered to be due to the release of copper that is bound to albumin. These results support the role of ceruloplasmin as a copper transport protein which releases copper at the cell surface, and a subsequent transport of the released copper in a manner similar to that of copper chloride or copper-histidine complexes.
Mas
A
A
Research institute, Hospital for Sick Children, Toronto, Canada.
Sarkar
B
B
D001692:Biological Transport; D002478:Cells, Cultured; D002570:Ceruloplasmin / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D003301:Copper Radioisotopes; D006639:Histidine / Q000378:metabolism; D006801:Humans; D010920:Placenta / Q000378:metabolism; D013997:Time Factors; D014327:Trophoblasts / Q000378:metabolism*
D003301:Copper Radioisotopes; D006639:Histidine; D003300:Copper; D002570:Ceruloplasmin; C029892:cupric chloride