Summary
Some of the target organs for nitrosamine carcinogenicity have a low activating capacity but many carcinogenic nitrosamines can be activated in the liver. Conjugates, such as phosphates, are chemically accessible reaction products of 1-OH-nitrosamines, and are either potential detoxication products or potential transport forms for activated nitrosamines.14C-labeled 1-(N-ethyl-N-nitrosamino)ethyl phosphate was tested for its ability to enter primary rat hepatocytes but no uptake was detectable. No uptake was observable into fibroblasts and human leukocytes.N-Nitrosomethylbenzylamine is efficiently 1-C-hydroxylated by hepatocytes but the corresponding 1-C-phosphate was detectable neither in the cells nor in the surrounding medium.N-Nitrosamino-1-phosphates, unlike 1-glucuronides, therefore, do not seem to be important for nitrosamine toxicokinetics.
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Abbreviations
- MNEP:
-
1-(N-methyl-N-nitrosamino)ethyl phosphate
- ENEP:
-
1-(N-ethyl-N-nitrosamino)ethyl phosphate
- [14C]ENEP:
-
1-(N 14C]ethyl-N-nitrosamino)-ethyl phosphate)
- N[14]MBzA:
-
N-nitroso-[14C]methylbenzylamine
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Dedicated to Professor Dr. D. Schmähl on the occasion of his 65th birthday
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Frei, E., Frank, N. & Wiessler, M. N-Nitrosamino phosphates are unlikely transport forms for activated nitrosamines. J Cancer Res Clin Oncol 116, 569–574 (1990). https://doi.org/10.1007/BF01637076
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DOI: https://doi.org/10.1007/BF01637076