Characterization of the beta-adrenergic receptor of the rat peritoneal macrophage.
The beta-adrenergic receptor was characterized on BCG-activated rat peritoneal macrophage membranes by radio-ligand binding studies. Saturable binding with [125I]iodocyanopindolol (125I-ICYP) was demonstrated. With Scatchard analysis, rat macrophages demonstrate approximately 1000 receptors per cell with a Kd of 5 X 10(-11) M for 125I-ICYP. Competition curves with (-) and (+) propranolol at concentrations below 10(-6) M confirmed stereospecificity. The potency of various ligands to compete for 125I-ICYP binding sites followed the order: propranolol greater than isoproterenol greater than epinephrine greater than norepinephrine with apparent Kd of 2.0 X 10(-9), 3.9 X 10(-7), 1.0 X 10(-5), and 2.5 X 10(-5) M, respectively. Isoproterenol-stimulated adenylate cyclase activity was two-fold above basal activity. The potential physiologic significance of a beta-adrenergic receptor on rat peritoneal macrophages was suggested by a dose-dependent decrease in phagocytosis of soluble, model immune complexes (aggregated gamma-globulin) by macrophages incubated with metaproterenol. We conclude that the rat macrophage has a beta-adrenergic receptor and that catecholamines may thereby modulate macrophage function.
Abrass
C K
CK
O'Connor
S W
SW
Scarpace
P J
PJ
Abrass
I B
IB
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D020120:Iodocyanopindolol; D008264:Macrophages / Q000378:metabolism* / Q000502:physiology; D008297:Male; D009921:Metaproterenol / Q000494:pharmacology; D010529:Peritoneal Cavity / Q000166:cytology; D010587:Phagocytosis / Q000187:drug effects; D010869:Pindolol / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000032:analysis* / Q000187:drug effects
D011943:Receptors, Adrenergic, beta; D009921:Metaproterenol; D020120:Iodocyanopindolol; D010869:Pindolol; D000242:Cyclic AMP; D015056:1-Methyl-3-isobutylxanthine