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Faith M. Williams - One of the best experts on this subject based on the ideXlab platform.
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Metabolism of Aldrin to dieldrin by rat skin following topical application
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 1991Co-Authors: M.j. Graham, Faith M. Williams, M. D. RawlinsAbstract:Abstract Metabolism of the pesticide Aldrin to dieldrin in the rat was studied following topical and ip administration of 0.1–10 mg Aldrin/kg body weight. When Aldrin was applied topically to the dorsal skin at a dose of 10 mg/kg body weight, absorption was less efficient than after ip administration; lower blood levels of Aldrin and dieldrin were seen and peak dieldrin levels were delayed. After ip administration of 1 or 10 mg Aldrin/kg body weight, dieldrin was found at similar concentrations in the dorsal and ventral skin 7 hr later, whereas 7 hr after topical administration of 10 mg Aldrin/kg, the dieldrin concentration in the skin at the dorsal site of application was four times higher than that at a ventral skin site. Similar differences in dieldrin concentrations between dorsal and ventral skin persisted throughout the 7-hr period following topical application. The results indicate that topically applied Aldrin is metabolized to dieldrin in the skin during absorption, but the overall proportion of metabolism that takes place in the skin is small compared with the contribution of the liver. Dieldrin was not detected in the ventral skin remote from the application site 1 hr after topical application of Aldrin, whereas a dieldrin concentration of 2.2 nmol/g was detected in the skin of the application site at this time; more than 99% of this dieldrin was probably formed locally by dermal metabolism of percutaneously absorbed Aldrin. The efficiency of conversion of applied Aldrin to dieldrin decreased with increasing Aldrin dose in the range 0.1 to 10 mg/kg.
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Percutaneous absorption and metabolism of Aldrin by rat skin in diffusion cells.
Archives of toxicology, 1991Co-Authors: Sara E. Macpherson, Robert C. Scott, Faith M. WilliamsAbstract:Using a static diffusion cell with varying receptor fluids the viability of isolated rat skin mounted as whole skin or as split thickness skin has been studied. Skin viability decreased with time with phosphate buffer or Eagles MEM and was not supported with ethanol/water as the receptor fluid. The pesticide Aldrin was absorbed through the skin into ethanol/water but not the aqueous receptor fluids. With viable skin preparations Aldrin was metabolised to dieldrin and absorbed Aldrin and the metabolite remained in the skin. Viable skin preparations must be used to assess in vitro, the degree of metabolism of xenobiotics which occurs during percutaneous absorption.
Ryuichiro Kondo - One of the best experts on this subject based on the ideXlab platform.
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novel metabolic pathways of organochlorine pesticides dieldrin and Aldrin by the white rot fungi of the genus phlebia
Chemosphere, 2011Co-Authors: Pengfei Xiao, Kazuhiro Takagi, Hiromasa Kiyota, Ichiro Kamei, Toshio Mori, Ryuichiro KondoAbstract:White rot fungi can degrade a wide spectrum of recalcitrant organic pollutants, including polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated biphenyls (PCBs). In this experiment, 20 white rot fungi, belonging to genus Phlebia, were investigated for their ability to degrade dieldrin. Based on the screening results, we further investigated Phlebia acanthocystis, Phlebia brevispora, and Phlebia aurea to determine their degradation capacity and metabolic products towards dieldrin and Aldrin. The three fungi were able to remove over 50% of dieldrin in a low nitrogen medium, after 42 d of incubation. Three hydroxylated products were detected as metabolites of dieldrin, suggesting that in Phlebia strains, hydroxylation reactions might play an important role in the metabolism of dieldrin. In contrast to dieldrin, Aldrin exhibited higher levels of degradation activity. Over 90% of Aldrin was removed after 28 d of incubation, and several new metabolites of Aldrin in microorganisms, including 9-hydroxyAldrin and two carboxylic acid products, were detected in fungal cultures. These results indicate that the methylene moiety of Aldrin and dieldrin molecules might be prone to enzymatic attack by white rot fungi. In this study, we describe for the first time a new metabolic pathway of both compounds by fungi of genus Phlebia.
Sara E. Macpherson - One of the best experts on this subject based on the ideXlab platform.
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Percutaneous absorption and metabolism of Aldrin by rat skin in diffusion cells.
Archives of toxicology, 1991Co-Authors: Sara E. Macpherson, Robert C. Scott, Faith M. WilliamsAbstract:Using a static diffusion cell with varying receptor fluids the viability of isolated rat skin mounted as whole skin or as split thickness skin has been studied. Skin viability decreased with time with phosphate buffer or Eagles MEM and was not supported with ethanol/water as the receptor fluid. The pesticide Aldrin was absorbed through the skin into ethanol/water but not the aqueous receptor fluids. With viable skin preparations Aldrin was metabolised to dieldrin and absorbed Aldrin and the metabolite remained in the skin. Viable skin preparations must be used to assess in vitro, the degree of metabolism of xenobiotics which occurs during percutaneous absorption.
M K K Pillai - One of the best experts on this subject based on the ideXlab platform.
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Aldrin and dieldrin residues in human fat milk and blood serum collected from delhi
Human & Experimental Toxicology, 1992Co-Authors: Amit Nair, P Dureja, M K K PillaiAbstract:1 Aldrin and dieldrin residues were monitored in the fat, breast milk and blood serum from female residents of Delhi.2 The average Aldrin and dieldrin contents were 0.048 and 0.099 ppb in adipose tissue, 0.003 and 0.060 ppb in breast milk and 0.004 and 0.002 ppb in blood serum, respectively.3 The older donors contained higher levels of Aldrin and dieldrin in their adipose tissue.4 Primagravidae contained more of these chemicals in their breast milk.5 A positive correlation was observed between the Aldrin concentration in adipose tissue and breast milk, and that in adipose tissue and blood serum. Similarly, a significant correlation was found between dieldrin in adipose tissue and blood serum.6 The levels of Aldrin and dieldrin were low in samples from residents of Delhi when compared to those in developed countries.
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Levels of Aldrin and dieldrin in environmental samples from Delhi, India.
The Science of the total environment, 1991Co-Authors: Amit Nair, P Dureja, M K K PillaiAbstract:Aldrin and dieldrin residues in soil, earthworms, water, fish and clams from different sites in Delhi were monitored. Concentrations of Aldrin and dieldrin were found to be higher in earthworms than in soil. Concentrations of dieldrin were higher in fish than the ambient water, but the concentration of Aldrin in the ambient water was the same as that in fish and clams.
Boguslaw Buszewski - One of the best experts on this subject based on the ideXlab platform.
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clinoptilolite in study of lindane and Aldrin sorption processes from water solution
Journal of Hazardous Materials, 2008Co-Authors: Myroslav Sprynskyy, Tomasz Ligor, Boguslaw BuszewskiAbstract:Abstract The scope of this study was adsorption of lindane and Aldrin from water solution onto clinoptilolite rock with the following desorption using n -hexane. Both kinetic and equilibrium tests were conducted. During kinetic experiment the most part of Aldrin and a half part of lindane were sorbed during the first hours. The sorption equilibria with removal of 95% of Aldrin amount and about 68% of lindane amount have been set in for 48 h. The pseudo-second-order kinetics model gives somewhat better fit to the both pesticides’ sorption data that may testify to the complicated and heterogeneous nature of interaction between active zeolite surface and the pesticides polar-dipole centers. OH − -groups and the coordinated exchangeable cations are probably the main active positions for the pesticide sorption on the clinoptilolite surface. Equilibrium experiment results show that adsorption isotherms for the low concentrations of lindane and Aldrin (10–200 and 3–100 μg/L, respectively) fit well to the Freundlich and the Liner models. Only 10% of lindane sorbed and about 60% of Aldrin sorbed were desorbed from the clinoptilolite using n -hexane under static conditions.
