The development of molecular dosimetry methods will simplify the identification of people at high risk for cancer. A combined monoclonal antibody immunoaffinity chromatography/high performance liquid chromatography method has been devised to isolate and quantify aflatoxin-DNA adducts and other metabolites in rat urine samples. We report the production of 11 different monoclonal antibodies recognizing aflatoxin Bi, aflatoxin Qi, aflatoxin d, aflatoxicol, and aflatoxin Mi and the application of these antibodies to a multiple monoclonal antibody affinity chromatography technique. Using the multiple monoclonal antibody affinity column with rat urines obtained from dosed animals, between 90 and 95% of total aflatoxin metabolites can be bound to the column and isolated. Analytical immunoaffinity chromatography/high performance liquid chromatography analysis of these isolated aflatoxins reveals that more than 55% of the aflatoxins in rat urine are aflatoxin-dihydrodiol, aflatoxin-A ^ -guanine, aflatoxin Qi, aflatoxin Mi, aflatoxin Pi, and aflatoxin Bi, accounting for 1.5, 9.6, 1.8, 34.5, 8.0, and 1.0% of the total aflatoxins, respectively. Further, a perchloric acid digestion of the afla-toxin-A ^ -guanine peak was used to confirm its identity by its conversion to guanine. The measurement of aflatoxin-A ^ -guanine excretion in rat urine was examined to assess its utility as a marker of DNA adduct formation in the liver, and a dose-dependent excretion in urine was found with a correlation coefficient of 0.99. A comparison of the dose-dependent residual levels of aflatoxin binding to liver DNA with the amount of aflatoxin-A ^ -guanine excreted in urine showed a correlation coefficient of 0.98. Besides the nucleic acid adduct excretion data, aflatoxin Mi and aflatoxin Pt were evaluated as molecular dosimeters in the urine. Aflatoxin Mi was found to be an excellent marker, whereas no linear relationship between dose and aflatoxin Pi excretion in urine was found.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Jan 1992|
ASJC Scopus subject areas
- Cancer Research