Evidence is presented that the likely major amine precursors to N-nitrosopyrrolidine in cooked bacon are free proline in the adipose tissue and to a lesser extent, collagenous connective tissues. A model system in which animal lipid is replaced with hydrogenated vegetable oil is described and used in investigating the potential role of prolyl derivatives as precursors to N-nitrosopyrrolidine.
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http://dx.doi.org/10.1080/02652038509373552 | DOI Listing |
Environ Geochem Health
March 2024
Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China.
N-nitrosamines in reservoir water have drawn significant attention because of their carcinogenic properties. Karst reservoirs containing dissolved organic matter (DOM) are important drinking water sources and are susceptible to contamination because of the fast flow of various contaminants. However, it remains unclear whether N-nitrosamines and their precursor, DOM, spread in karst reservoirs.
View Article and Find Full Text PDFWater Res
February 2023
Center for Water Cycle Research, Korea Institute of Science and Technology, Hwarangro 14 gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea; Division of Energy and Environment Technology, KIST-School, University of Science and Technology, Seoul 02792, Republic of Korea. Electronic address:
Immobilized and visible-light-active titanium dioxide (TiO) is widely used for water treatment. However, the accelerated generation of degradation byproducts is a potential risk of TiO-based photocatalysis. This study aimed to investigate the structural effect of engineered TiO samples on the formation of major nitrosamines during photocatalysis.
View Article and Find Full Text PDFSci Total Environ
June 2021
Institute of Environmental Engineering & Nano-Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; Guangdong Provincial Engineering Research Centre for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:
The presence of carcinogenic N-nitrosamines and dissolved organic matter (DOM) in freshwater is a significant concern from the perspective of public health and drinking water treatment plant operation. This study investigated the N-nitrosamines concentration and their precursors' distributions, and DOM composition in four reservoirs located in a southern city of China. A total of 22 renowned precursors were identified.
View Article and Find Full Text PDFEnviron Sci Technol
January 2021
Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2G3, Canada.
-Nitrosamine disinfection byproducts (DBPs) are a health concern because they are probable human carcinogens. Complex organic nitrogenous compounds, nitrosamine precursors, are largely unidentified in source water. Using stable isotopic labeling-enhanced nontargeted analysis, we identified a natural product -heterocyclic amine 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCCA) in source water.
View Article and Find Full Text PDFJ Toxicol Pathol
October 2019
Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
To clarify difference in the responses on the reprogramming of metabolism toward carcinogenesis between genotoxic and non-genotoxic hepatocarcinogens in the liver, rats were repeatedly administered genotoxic hepatocarcinogens (-nitrosodiethylamine, aflatoxin B, -nitrosopyrrolidine, or carbadox) or non-genotoxic hepatocarcinogens (carbon tetrachloride, thioacetamide, or methapyrilene hydrochloride) for 28, 84, or 90 days. Non-genotoxic hepatocarcinogens revealed transcript expression changes suggestive of suppressed mitochondrial oxidative phosphorylation (OXPHOS) after 28 days and increased glutathione -transferase placental form-positive (GST-P) foci downregulating adenosine triphosphate (ATP) synthase subunit beta, mitochondrial precursor (ATPB), compared with genotoxic hepatocarcinogens after 84 or 90 days, suggesting that non-genotoxic hepatocarcinogens are prone to suppress OXPHOS from the early stage of treatment, which is in contrast to genotoxic hepatocarcinogens. Both genotoxic and non-genotoxic hepatocarcinogens upregulated glycolytic enzyme genes and increased cellular membrane solute carrier family 2, facilitated glucose transporter member 1 (GLUT1) expression in GST-P foci for up to 90 days, suggesting induction of a metabolic shift from OXPHOS to glycolysis at early hepatocarcinogenesis by hepatocarcinogens unrelated to genotoxic potential.
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