Prostaglandin E1 binding protein on the surface of primary cultured hepatocytes.
Prostaglandin E1 (PGE1) was bound to primary cultured rat hepatocytes in a receptor-dependent manner in serum-free medium at 4 degrees C. When added at a concentration of 2 X 10(-9) M, maximal specific binding occurred within 60-90 min. Trypsin treatment of the cells reduced the binding capacity to about 50% of that of untreated cells. Scatchard-analysis of the binding data showed that the cells had an apparent dissociation constant of 1.2 X 10(-8) M and a binding capacity of 580 fmol (approximately 3.5 X 10(11) PGE1 receptors)/mg of protein. In experiments at 37 degrees C, maximal specific binding occurred within 5 min and was 6-7 times that at 4 degrees C, but the amount of bound PGE1 decreased rapidly after 5 min due to metabolism of PGE1 in the hepatocytes. Thin-layer chromatographic analysis showed that the material bound to the cell surface consisted of intact PGE1 and its metabolites at 37 degrees C, but PGE1 only at 4 degrees C.
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D011458:Prostaglandins E / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011982:Receptors, Prostaglandin / Q000378:metabolism*; D018078:Receptors, Prostaglandin E
D011458:Prostaglandins E; D011982:Receptors, Prostaglandin; D018078:Receptors, Prostaglandin E