Expression of haemopexin receptors by cultured human cytotrophoblast
The expression of cell-surface haemopexin (Hx) receptors on human cytotrophoblasts was assessed by using four different Hx species purified from plasma: human Hx isolated by wheatgerm-affinity chromatography, human Hx isolated by haem-agarose-affinity chromatography and rabbit and rat Hx, also isolated by haem-agarose-affinity chromatography. About 3500-7000 high-affinity (Kd 0.34-0.85 nM) receptors per cell were measured by Scatchard-type analysis at 4 degrees C using human (species obtained by both methods) or rabbit 125I-labelled haem-Hx. Measured simultaneously, transferrin receptor number and affinity were 40,000/cell and 0.83 nM respectively. In contrast with transferrin receptors, the number of Hx receptors did not increase during 24 h in cytotrophoblast culture. Rat Hx showed no specific binding to human Hx receptors in cytotrophoblast cultures.
|Keywords||Animals, Cells, Cultured, Comparative Study, Female, Hemopexin/metabolism, Humans, Kinetics, Pregnancy, Rabbits, Rats, Receptors, Peptide/metabolism/*physiology, Receptors, Transferrin/metabolism, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S., Species Specificity, Trophoblasts/*metabolism/*ultrastructure|
van Dijk, H.P., Kroos, M.J., Starreveld, J.S., van Eijk, H.G., Tang, S.P., & Song, D.X.. (1995). Expression of haemopexin receptors by cultured human cytotrophoblast. Biochemical Journal. Retrieved from http://hdl.handle.net/1765/8557