Phenylarsine oxide-induced increase in alveolar macrophage surface receptors: evidence for fusion of internal receptor pools with the cell surface.
Rabbit alveolar macrophages which were treated at 0 degrees C with phenylarsine oxide and then incubated at 37 degrees C for 10 min exhibited a two- to threefold increase in surface receptor activity for macroglobulin.protease complexes, diferric transferrin, and mannose-terminal glycoproteins. Analysis of the concentration-dependence of ligand binding indicated that changes in ligand-binding activity were due to changes in receptor number rather than alterations in ligand-receptor affinity. Surface receptor number could also be increased by treatment of cells with three other sulfhydryl reagents, N-ethylmaleimide, p-chloromercurobenzoate, and iodoacetic acid. The increase in receptor activity was maximal after 10 min and decreased over the next hour. This decrease in cell-associated receptor activity was due to the release of large membrane vesicles which demonstrated a uniform buoyant density by isopycnic sucrose gradient centrifugation. Treatment of cells with phenylarsine oxide did not decrease the cellular content of lactate dehydrogenase or beta-galactosidase, indicating that cell integrity was maintained and lysosomal enzyme release did not occur. Our studies indicate that phenylarsine oxide treatment in the presence of extracellular Ca2+ results in the fusion of receptor-containing vesicles with the cell surface.
J
J
Kaplan
D M
DM
Ward
H S
HS
Wiley
D000818:Animals; D001152:Arsenicals / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects; D007425:Intracellular Membranes / Q000378:metabolism; D037181:Lectins, C-Type; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology; D008274:Magnesium / Q000494:pharmacology; D008358:Mannose / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008561:Membrane Fusion / Q000187:drug effects; D008744:Methylamines / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000166:cytology; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D011952:Receptors, Concanavalin A / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism; D011990:Receptors, Transferrin; D012709:Serum Albumin; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D014357:Trypsin / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000378:metabolism
D001152:Arsenicals; D037181:Lectins, C-Type; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008744:Methylamines; D011956:Receptors, Cell Surface; D011952:Receptors, Concanavalin A; D011971:Receptors, Immunologic; D011990:Receptors, Transferrin; D012709:Serum Albumin; D013439:Sulfhydryl Reagents; C028939:alpha-2-macroglobulin-trypsin complex; D000511:alpha-Macroglobulins; C023840:mannose-bovine serum albumin conjugate; C029341:oxophenylarsine; D012710:Serum Albumin, Bovine; C027451:methylamine; D014357:Trypsin; D008274:Magnesium; D008358:Mannose; D002118:Calcium