The Disinfection By-Products Dichloro-, Dibromo-, and Bromochloroacetic Acid Impact Intestinal Microflora and Metabolism in Fischer 344 Rats upon Exposure in Drinking Water
| Autor: | Gail M. Nelson, S. E. George, Anthony B. DeAngelo, K. C. Bailey, L. R. Brooks, Michael H. George, Adam Swank |
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| Rok vydání: | 2000 |
| Předmět: |
Male
medicine.medical_specialty Haloacetic acids Dichloroacetic acid Acetates Toxicology chemistry.chemical_compound Cecum Water Supply Internal medicine medicine Animals Toxicokinetics Ingestion skin and connective tissue diseases Carcinogen Bacteria Dichloroacetic Acid biology Body Weight Organ Size Metabolism Rats Inbred F344 Enzyme assay Rats Intestines Endocrinology medicine.anatomical_structure chemistry Biochemistry biology.protein Water Pollutants Chemical medicine.drug |
| Zdroj: | Toxicological Sciences. 56:282-289 |
| ISSN: | 1096-0929 |
| Popis: | Human consumption of chlorinated drinking water has been linked epidemiologically to bladder, kidney, and rectal cancers. The disinfection by-product (DBP) dichloroacetic acid is a hepatocarcinogen in Fischer 344 rats and B6C3F1 mice. The objective of this study is to determine the effect of the DBPs dichloro-, bromochloro-, and dibromoacetic acids (DCA, BCA, DBA) on intestinal microbial populations and their metabolism, with emphasis on enzymes involved in the bioactivation of procarcinogens and promutagens. One-month-old male Fischer 344 rats were provided water ad libitum containing 1 g/l DCA, BCA, or DBA for up to 5 weeks. At 1, 3, and 5 weeks of treatment, beta-glucuronidase (GLR), beta-galactosidase (GAL), beta-glucosidase (GLU), nitroreductase (NR), azoreductase (AR), and dechlorinase (DC) activities were determined in cecal and small and large intestinal homogenates. After 5 weeks of treatment, intestinal populations were enumerated on selective media. Cecal GAL (DCA, BCA, DBA) and GLR (DCA, DBA) activities were reduced after 1 and 3 weeks of treatment and GAL activity was elevated at 5 weeks (BCA). Large intestinal GAL (DCA, BCA) and GLU (DCA, BCA, DBA) activities were elevated after 5 weeks of treatment. Week 5 cecal AR (DCA, BCA, DBA), NR (DCA), and DC (DCA, DBA) activities were reduced. Even though some significant changes in intestinal populations were observed, use of selective media was not sensitive enough to explain fluctuations in enzyme activity. Haloacetic acids in the drinking water alter intestinal metabolism, which could influence bioactivation of promutagens and procarcinogens in the drinking water. |
| Databáze: | OpenAIRE |
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