Combination effects in chemical carcinogenesis.
Only very few malignant tumors in human beings can be attributed to one single chemical substance. Therefore, combination effects are of particular practical relevance. Up to now, the experimental examination of this problem has been neglected to a great extent. Methods for the examination of syncarcinogenesis are presented and the results of studies are discussed. The most essential finding was the fact that syncarcinogenic additive effects are observed when substances with the same organotropism, but with different chemical structures are applied simultaneously or in sequence. However, no syncarcinogenic effect is observed when substances with different organotropisms are applied. An enhancement of chemical carcinogenesis was not found after simultaneous application of a non-carcinogenic, but organotropic agent. Immunosuppression or immunostimulation of the host did not have an impact on chemical carcinogenesis.
D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D004347:Drug Interactions; D007114:Immunization; D007165:Immunosuppression Therapy; D008297:Male; D051381:Rats
D002273:Carcinogens