Tumour initiation in mouse skin by 7,12-dimethylbenz[a]anthracene: irrelevance of systemic activation.
The effect was investigated of 7,8-benzoflavone (BF) on tumour initiation by 7,12-dimethylbenz[a]anthracene (DMBA) applied either intragastrically or topically. A single topical application of BF drastically decreased tumour initiation via both routes. This decrease was in both cases inversely proportional to the interval between administration of DMBA and BF. The data suggest that the decisive step of metabolic activation of DMBA is mediated by cytochrome P-448 dependent monooxygenase(s) located within the epidermis.
D015127:9,10-Dimethyl-1,2-benzanthracene / Q000008:administration & dosage / Q000378:metabolism; D000818:Animals; D001551:Benz(a)Anthracenes; D001571:Benzoflavones / Q000008:administration & dosage; D019388:Cytochrome P-450 CYP1A2; D003580:Cytochromes / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D051379:Mice; D009374:Neoplasms, Experimental / Q000139:chemically induced; D010105:Oxygenases / Q000378:metabolism; D012867:Skin / Q000201:enzymology; D012878:Skin Neoplasms / Q000139:chemically induced*
D001551:Benz(a)Anthracenes; D001571:Benzoflavones; D003580:Cytochromes; D015127:9,10-Dimethyl-1,2-benzanthracene; D010105:Oxygenases; C017170:Cyp1a2 protein, rat; D019388:Cytochrome P-450 CYP1A2