Substantial evidence has been assembled suggesting the possible health risk from exposure to N-nitroso compounds. Sander1 originally proposed the concept of endogenous intragastric nitrosation, a process capable of generating carcinogenic N-nitroso compounds in humans. It has also been demonstrated that N-nitroso compounds are formed endogenously in animals given nitrite and a suitable amine2,3. However, the initial research on endogenous synthesis of N-nitroso compounds in humans was complicated by the presence of numerous artifacts of the analytical methods and the collection procedures. A method proposed by Ohshima and Bartsch4 was the first potentially suitable procedure for estimating daily human exposure to endogenously formed N-nitroso compounds. The monitoring of urinary levels of N-nitrosoproline (NPRO) after dosing with nitrate and proline was utilized in a human volunteer without adverse biological effects. Since this publication, a number of other investigators have used this procedure to demonstrate the endogenous formation of nitrosoproline as well as other nitrosoamino acids in humans.
KeywordsAscorbic Acid Methyl Oleate Coeliac Disease Pernicious Anemia Cancer Etiology
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