© 1994 Oxford University Press
research-article |
In vitro formation and degradation of 2-amino-1-methyl-6-phenyliinidazo[4,5-b]pyridine(PhIP) protein adducts
1National Institute for Consumer Research PO Box 173, N-1324 Lysaker, Norway
2National Institute of Public Health Department of Environmental Medicine, Geirmyrsveien 75, N-0462 Oslo, Norway
3Danish National Food Agency, Institute of Toxicology DK-2860 Søborg, Denmark
4Swedish University of Agricultural Sciences PO Box 7015, S-750 07 Uppsala, Sweden
Adduct formation between the food mutagen 2-amino-1-methyl-6-phenylimidazo[4,5-b](PhIP) and rat serum albumin (RSA) was studied in vitro using hepatic microsomes isolated from polychiorinated biphenyl induced rats. With 1-methyl-2-nitro-6-phenylimidazo[4,5-b]pyridine (2-nitro-PhIP) as starting material, four main products were formed. Pretreatment of RSA with ß-mercaptoethanol markedly increased the yield of one of them. In this adduct, the C-2 of PhIP was linked to cysteine of RSA at position 34 in a C-S linkage. With N2-acetoxy-PhIP as starting material, unstable conjugates were formed with RSA as well as with glutathione (GSH) and cysteine. The suggested structures of the GSH-S-n2 and cysteine conjug ates, GSH-S-N2-PhIP and cysteine-S-N2-PhIP respectively, are based on mass spectra and UV spectra. The degradation of the conjugates of GSH and cysteine as well as of the protein adduct were monitored. They all resulted in the same degradation product, identified as 2-amino-5 hydroxy-1-methyl-6-phenylimidazo[4,5b]pyridine (5-hydroxy-PhIP).
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
S. Langouet, A. Paehler, D. H. Welti, N. Kerriguy, A. Guillouzo, and R. J. Turesky Differential metabolism of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in rat and human hepatocytes Carcinogenesis, January 1, 2002; 23(1): 115 - 122. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. P. Nelson, L. C. R. Kidd, J. Sauvageot, W. B. Isaacs, A. M. De Marzo, J. D. Groopman, W. G. Nelson, and T. W. Kensler Protection against 2-Hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine Cytotoxicity and DNA Adduct Formation in Human Prostate by Glutathione S-Transferase P1 Cancer Res., January 1, 2001; 61(1): 103 - 109. [Abstract] [Full Text] |
||||
![]() |
H. Frandsen and J. Alexander N-acetyltransferase-dependent activation of 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine: formation of 2-amino-1-methyl-6-(5-hydroxy)phenylimidazo [4,5-b]pyridine, a possible biomarker for the reactive dose of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine Carcinogenesis, June 1, 2000; 21(6): 1197 - 1203. [Abstract] [Full Text] [PDF] |
||||

