ACTIVATION OF CARCINOGENS AND MUTAGENS BY RAT COLON MUCOSA

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  • 1 January 1978
    • journal article
    • research article
    • Vol. 38  (9) , 2939-2944
Abstract
Colon mucosal cells can catalyze the activation of precarcinogens to mutagenic metabolites without the intermediacy of intestinal bacteria as shown in a mutagenesis assay system composed of Salmonella typhimurium strain TA100 and the 9000 .times. g supernatant fraction of rat colon mucosal cells. Pretreatment of rats with .beta.-naphthoflavone increased the activation of 2-aminoanthracene 10- to 20-fold and the activation of benzo(a)pyrene 4-fold. Pretreatment of rats with Aroclor 1254 doubled the activation of 2-aminoanthracene over control but had no effect on the activation of benzo(a)pyrene. The activation of 2-aminoanthracene and benzo(a)pyrene by liver was induced significantly by pretreatment with .beta.-naphthoflavone and Aroclor 1254. Phenobarbital/hydrocortisone pretreatment did not increase activation by the colon system of any precarcinogen tested but increased the activation of 2-aminoanthracene, cyclophosphamide and isophosphamide by the liver system. The activation of precarcinogens in the bacterial test system is directly correlated with the activities of the pretreated colon and liver preparations toward several drug and polycyclic hydrocarbon substrates assayed in vitro.