The uptake of immune complexes by macrophages (MP) may be important in disease states in which circulating immune complexes are increased. We undertook the present study to determine the effects of prostaglandin E2 (PGE2) and adenosine 3',5'-cyclic monophosphate (cAMP) on the uptake of immunoglobulin G complexes (IgG complexes) by MP. The uptake of 125I-IgG-gold particles (IgG-gold) was measured in the established MP cell line J774.16 following pretreatment with PGE2, the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), PGE2 plus IBMX, the cyclooxygenase inhibitor indomethacin (IM), and dibutyryladenosine 3',5'-cyclic monophosphate (DBcAMP). Preincubation with PGE2 at concentrations from (10(-12)) to (10(-5) M) revealed significantly diminished uptake of IgG-gold at (10(-6)) and (10(-5) M) (in counts per min per well, PGE2 [10(-6) M], 5,401 +/- 140; control, 17,150 +/- 493, p less than 0.001); (PGE2 [10(-5) M], 3,835 +/- 172; control, 17,150 +/- 493, p less than 0.001). IBMX (10(-3) M) alone did not significantly alter IgG-gold uptake (IBMX, 14,450 +/- 1938; control, 14,840 +/- 995, p less than 1.0). PGE2 (10(-6) M) plus IBMX (10(-3) M) significantly suppressed IgG-gold uptake (in counts per min per well, PGE2 plus IBMX, 3,659 +/- 129; control 18,296 +/- 486, p less than 0.001). PGE2 (10(-6) M) alone also suppressed IgG-gold uptake versus control (PGE2, 4,578 +/- 105; control, 18,296 +/- 486, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)