title: Regulation of macrophage-mediated tumor cell killing by prostaglandins: comparison of the effects of PGE2 and PGI2.
abstract: Mouse resident peritoneal macrophages stimulated in vitro by purified bacterial lipopolysaccharide (LPS) produced both prostaglandin E2 (PGE2) and prostaglandin I2 (PGI2), the latter detected as its stable metabolite, 6-keto PGF1 alpha. Maximum production, induced in each case by 1 ng/ml purified LPS, was in the range of 10(-7)M for PGI2 and 3 x 10(-8)M for PGE2. A quantitatively similar increase in intracellular levels of macrophage cyclic AMP (measured on a whole cell basis), with a similar duration of effect, was stimulated by PGE2 and PGI2; however, only PGE2 had a negative regulatory effect on macrophage activation for tumor cell killing. These data confirm that more than a whole cell increase in the concentration of cyclic AMP is needed to shut off nonspecific tumor cell killing mediated by LPS-activated resident peritoneal macrophages.
mesh_terms: D000818:Animals; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D015232:Dinoprostone; D011464:Epoprostenol / Q000096:biosynthesis / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D008297:Male; D012515:Mast-Cell Sarcoma / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D011453:Prostaglandins / Q000494:pharmacology*; D011458:Prostaglandins E / Q000096:biosynthesis / Q000494:pharmacology*
chemical_list: D008070:Lipopolysaccharides; D011453:Prostaglandins; D011458:Prostaglandins E; D011464:Epoprostenol; D000242:Cyclic AMP; D015232:Dinoprostone