Toxicity of Trp-P-2 to cultured human and rat keratinocytes.
Chem Biol Interact
; 127(3): 237-53, 2000 Jul 14.
Article
en En
| MEDLINE
| ID: mdl-10967320
ABSTRACT
Keratinocytes cultured from human and rat epidermis exhibited strongly divergent sensitivities to toxicity from the heterocyclic amine food mutagen Trp-P-2. To find a biochemical basis for this difference, the cultured cells were compared in their expression of phase 1 and 2 biotransformation activities, mutagenic activation and macromolecular adducts. The human and early passage rat cells expressed similar levels of ethoxyresorufin O-deethylase and N-acetyl transferase activities, their microsomes were similarly active in inducing bacterial mutagenesis when incubated with Trp-P-2, and the keratinocytes accumulated similar levels of DNA adducts over a 4-day treatment period. However, the human cells expressed an order of magnitude higher cytosolic glutathione S-transferase activity than the rat cells, likely providing enhanced protection. Late passage rat epidermal cells were insensitive to Trp-P-2 toxicity, attributable to their rapid loss of measured cytochrome P450 activity. Rat esophageal and fore-stomach epithelial cells resembled late passage rat epidermal cells in their lack of sensitivity to Trp-P-2 toxicity and lack of P450 activity. Human esophageal epithelial cells expressed substantial P450 activity but, in contrast to human epidermal cells, were sensitive to Trp-P-2 toxicity. Thus keratinocytes provide a valuable system in which to examine the basis for species- and tissue-specific differences in toxicity from this carcinogenic heterocyclic amine.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Carbolinas
/
Queratinocitos
/
Mutágenos
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Chem Biol Interact
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos