title: Benzo[a]pyrene initiates enzyme-altered islands in the liver of adult rats following single pretreatment and promotion with polychlorinated biphenyls.
abstract: Treatment of adult female rats with a single dose of benzo[a]pyrene (BaP) fails to initiate preneoplastic enzyme-altered islands in their livers. Treatment with polychlorinated biphenyls (PCBs) at a dose which strongly induces aryl hydrocarbon(BaP)hydroxylase prior to BaP application and followed by promotion with PCBs causes the appearance of about 9 adenosine-5'-triphosphatase-deficient and 7 gamma-glutamyltranspeptidase-positive islands/cm2 after 12 weeks. PCB-pretreatment or promotion alone did not increase the BaP-dependent formation of islands above that of the PCB-treated controls (2-3 islands/cm2). The results suggest that upon alteration of its metabolism BaP causes the formation of preneoplastic lesions in the liver which become manifest by promotion.
mesh_terms: D000217:Acyltransferases / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism*; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000633:toxicity*; D002273:Carcinogens / Q000633:toxicity*; D005260:Female; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D011292:Premedication; D051381:Rats; D011919:Rats, Inbred Strains; D011503:Transglutaminases
chemical_list: D001580:Benzopyrenes; D002273:Carcinogens; D001564:Benzo(a)pyrene; D011078:Polychlorinated Biphenyls; D001189:Aryl Hydrocarbon Hydroxylases; D000217:Acyltransferases; D011503:Transglutaminases; D000251:Adenosine Triphosphatases