Binding and internalization of 125I-Bolton-Hunter-substance-P by pancreatic acinar cells.
Binding of 125I-labelled Bolton-Hunter substance P (125I-BH-SP) to dispersed pancreatic acinar cells from guinea pigs was studied. Association of 125I-BH-SP to acinar cells was rapid, specific, and temperature-dependent. Dissociation of bound 125I-BH-SP was slow and 60 min after dilution only 12% of cell-associated radioactivity had dissociated from cells. Various c-terminal fragments of SP as well as structurally related substances inhibited binding. Bound 125I-BH-SP partly resisted acid washes of cells. After lysis of cells, cell-associated radioactivity was chromatographed on a Sephadex G-25 column. Part of radioactivity was eluted as apparently intact 125I-BH-SP. It is suggested that this material has been internalized into acinar cells.
D000818:Animals; D001667:Binding, Competitive; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D006168:Guinea Pigs; D007700:Kinetics; D010179:Pancreas / Q000166:cytology / Q000378:metabolism*; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism*; D013388:Succinimides / Q000378:metabolism*
C043194:Bolton Hunter reagent-substance P conjugate; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; D013388:Succinimides; D013373:Substance P