Background
Male reproductive toxicity induced by exposure to bisphenol A (BPA) has been widely reported. The testes have proven to be a major target organ of BPA toxicity, so studying testicular metabolite variation holds promise for the discovery of mechanisms linked to the toxic effects of BPA on reproduction.
Methodology/Principal Findings
Male Sprague-Dawley rats were orally administered doses of BPA at the levels of 0, 50 mg/kg/d for 8 weeks. We used an unbiased liquid chromatography-quadrupole time-of-flight (LC-QTOF)-based metabolomics approach to discover, identify, and analyze the variation of testicular metabolites. Two n-6 fatty acids, linoleic acid (LA) and arachidonic acid (AA) were identified as potential testicular biomarkers. Decreased levels of LA and increased levels of AA as well as AA/LA ratio were observed in the testes of the exposed group. According to these suggestions, testicular antioxidant enzyme levels were detected. Testicular superoxide dismutase (SOD) declined significantly in the exposed group compared with that in the non-exposed group, and the glutathione peroxidase (GSH-Px) as well as catalase (CAT) also showed a decreasing trend in BPA treated group.
Conclusions/Significance
BPA caused testicular n-6 fatty acid composition variation and decreased antioxidant enzyme levels. This study emphasizes that metabolomics brings the promise of biomarkers identification for the discovery of mechanisms underlying reproductive toxicity.
Lipid autoxidation is one of the main pathways for the formation of volatiles in meat. Investigations into how the unsaturated fatty acid (UFA) chains in lipids are autoxidized into volatiles are of great importance and could facilitate aroma research. In this study, taking UFAs as the research model, understanding of the formation of volatiles from the UFAs’ autoxidation has been updated and new pathways for furaldehyde derivatives have been proposed. The types of volatile produced were determined by the position and the number of C=C bonds as well as the methylene group flanked by the C=C bond. When the number of carbon atoms adjacent to C=C increases, the carbon lengths of aliphatic aldehydes elongate. Additionally, the number of methylene groups flanked by the C=C bond in PUFAs determine the types of aldehydes, alkanals, alkenals or alkadienals, as well as ketones. Apart from the alkyl furans, also furaldehydes and other derivatives could be produced from the oxidation of n-3 and n-6 fatty acids with over two C=C bonds, instead of from the Maillard reaction. This study presents the direct proof of the correlation between fatty acids and volatiles, and could also provide the theoretical basis for elevating aroma through lipid regulation.
危险品化学品经营许可证（带存储）