title: Suppressive effects of 3-methylcholanthrene on the in vitro antitumor activity of naturally cytotoxic cells.
abstract: Transient suppression of splenic natural killer (NK), natural cytotoxic (NC), and peritoneal macrophage cytotoxicity was observed following a single injection of 3-methylcholanthrene (3-MC) into C3H/HeN mice. Natural killer cell activity was depressed by 30-60% 4-6 d after injection of 1.0 mg 3-MC. Levels of NK reactivity returned to normal 8 d post 3-MC injection, and no suppression of natural killing was seen when tested 6 wk after 3-MC treatment. 3-MC did not affect Propionibacterium acnes augmentation of NK cell activity when tested both 6 d and 6 wk after carcinogen injection. The results indicate that the observed suppression of naturally cytotoxic cells may not be important in allowing 3-MC-induced tumors to grow, since suppression is not long-lasting. Therefore, any effect on tumor growth mediated by a suppression of naturally cytotoxic cells would have to be exerted at the earliest stages of tumor development.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000187:drug effects / Q000276:immunology; D002210:Caprylates / Q000494:pharmacology; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D007165:Immunosuppression Therapy; D007279:Injections, Subcutaneous; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D008748:Methylcholanthrene / Q000276:immunology* / Q000633:toxicity; D051379:Mice; D008809:Mice, Inbred C3H; D009374:Neoplasms, Experimental / Q000276:immunology; D011458:Prostaglandins E / Q000096:biosynthesis; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D014280:Triglycerides / Q000494:pharmacology
chemical_list: D002210:Caprylates; D011458:Prostaglandins E; D014280:Triglycerides; D008748:Methylcholanthrene; C003637:tricaprylin