Search results for "Dioxin"
showing 10 items of 59 documents
Transcriptional profiling of rat hypothalamus response to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin
2015
In some mammals, halogenated aromatic hydrocarbon (HAH) exposure causes wasting syndrome, defined as significant weight loss associated with lethal outcomes. The most potent HAH in causing wasting is 2,3,7,8-tetrachlorodibenzo-r-dioxin (TCDD), which exerts its toxic effects through the aryl hydrocarbon receptor (AHR). Since TCDD toxicity is thought to predominantly arise from dysregulation of AHR-transcribed genes, it was hypothesized that wasting syndrome is a result of to TCDD-induced dysregulation of genes involved in regulation of food-intake. As the hypothalamus is the central nervous systems' regulatory center for food-intake and energy balance. Therefore, mRNA abundances in hypothala…
Cross-species transcriptomic analysis elucidates constitutive aryl hydrocarbon receptor activity
2014
Background Research on the aryl hydrocarbon receptor (AHR) has largely focused on variations in toxic outcomes resulting from its activation by halogenated aromatic hydrocarbons. But the AHR also plays key roles in regulating pathways critical for development, and after decades of research the mechanisms underlying physiological regulation by the AHR remain poorly characterized. Previous studies identified several core genes that respond to xenobiotic AHR ligands across a broad range of species and tissues. However, only limited inferences have been made regarding its role in regulating constitutive gene activity, i.e. in the absence of exogenous ligands. To address this, we profiled transc…
Cancer Risk Near a Polluted River in Finland
2004
The River Kymijoki in southern Finland is heavily polluted with polychlorinated dibenzo-p-dioxins and dibenzofurans and may pose a health threat to local residents, especially farmers. In this study we investigated cancer risk in people living near the river (less than 20.0 km) in 1980. We used a geographic information system, which stores registry data, in 500 m times 500 m grid squares, from the Population Register Centre, Statistics Finland, and Finnish Cancer Registry. From 1981 to 2000, cancer incidence in all people (N = 188884) and in farmers (n = 11132) residing in the study area was at the level expected based on national rates. Relative risks for total cancer and 27 cancer subtype…
Biomonitoring of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs)…
2020
Abstract The main objective of the present research was to evaluate the levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in the human milk of Spanish lactating women who participated in the BETTERMILK project so that exposure and risk could be assessed for these mothers and their breastfed children. The total ∑PCDD/Fs + dl-PCBs TEQ2005 concentrations in the upper-bound (UB) ranged from 1.29 to 13.48 pg TEQ2005 g−1 lipid. The estimated geometric mean level for the sum of PCDD/F and dl-PCBs was 4.10 and 4.42 pg TEQ2005 g−1 lipid, lower-bound (LB) and UB respectively and were below the reference leve…
Toxicological Profile of Ultrapure 2,2´,3,4,4´,5,5´-Heptachlorbiphenyl (PCB 180) in Adult Rats
2014
PCB 180 is a persistent non-dioxin-like polychlorinated biphenyl (NDL-PCB) abundantly present in food and the environment. Risk characterization of NDL-PCBs is confounded by the presence of highly potent dioxin-like impurities. We used ultrapure PCB 180 to characterize its toxicity profile in a 28-day repeat dose toxicity study in young adult rats extended to cover endocrine and behavioral effects. Using a loading dose/maintenance dose regimen, groups of 5 males and 5 females were given total doses of 0, 3, 10, 30, 100, 300, 1000 or 1700 mg PCB 180/kg body weight by gavage. Dose-responses were analyzed using benchmark dose modeling based on dose and adipose tissue PCB concentrations. Body w…
Occurrence of Brominated Persistent Organic Pollutants (PBDD/DFs, PXDD/DFs, and PBDEs) in Baltic Wild Salmon (Salmo salar) and Correlation with PCDD/…
2013
The contamination profiles of polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs), diphenyl ethers (PBDEs), and mixed monobromo/chloro dibenzo-p-dioxins (PXDDs) and dibenzofurans (PXDFs) were determined in the tissue of Baltic wild salmon and compared with those of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs). Out of the analyzed PXDD/DFs, only the 3-B-2,7,8-triCDF was detected (in the concentration range of 0.039-0.075 pg g(-1) fresh weight (f.w.)). The toxic equivalents (TEQs) for analyzed PBDD/DFs (0.074-0.142 pg TEQ g(-1) f.w.) were found to contribute on average 2.1% to the total PCDD/DF-PBDD/DF-TEQ. The total concentrations of 27 P…
Survey on the presence of non-dioxine-like PCBs (NDL-PCBs) in loggerhead turtles (Caretta caretta) stranded in south Mediterranean coasts (Sicily, So…
2017
A total of 71 loggerhead turtles (Caretta caretta) stranded along the coasts of Sicily (Southern Italy) were examined for nonâdioxine like polychlorinated biphenyl (NDL-PCB) levels in muscle and adipose tissue by a gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) method. The results revealed 6 high-indicator congener (â6PCBIND) levels in 45% of the loggerhead turtles examined, with mean values of 980.39 ± 2508.39 ng/g wet weight in adipose tissue and 102.53 ± 238.58 ng/g wet weight in muscle tissue. The hexachloro and heptachloro PCB congeners were the most abundant in both the sample types. The highest NDL-PCB levels were reached in an adipose tissue sample of a logg…
Synthesis and biological activity of new anti-inflammatory compounds containing the 1,4-benzodioxine and/or pyrrole system
2007
A series of substituted derivatives containing the 1,4-benzodioxine or pyrrole nucleus are described. All the newly synthesized compounds were examined for their in vitro and in vivo anti-inflammatory activity. Several derivatives, including (S)-2, 14 and 17, showed more anti-inflammatory activity in vivo in these assays (rat paw oedema induced by carrageenan) than the known classical anti-inflammatory agent ibuprofen, whereas other compounds like 1 were equipotent to ibuprofen. Compound 17 was the most outstanding derivative because of its remarkable in vivo anti-inflammatory activity. In this paper, we examine and discuss the structure-activity relationships and anti-inflammatory activiti…
Transcriptional profiling of rat white adipose tissue response to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin
2015
Polychlorinated dibenzodioxins are environmental contaminants commonly produced as a by-product of industrial processes. The most potent of these, 2,3,7,8-tetrachlorodibenzo-rho-dioxin (TCDD), is highly lipophilic, leading to bioaccumulation. White adipose tissue (WAT) is a major site for energy storage, and is one of the organs in which TCDD accumulates. In laboratory animals, exposure to TCDD causes numerous metabolic abnormalities, including a wasting syndrome. We therefore investigated the molecular effects of TCDD exposure on WAT by profiling the transcriptomic response of WAT to 100 mu g/kg of TCDD at 1 or 4 days in TCDD-sensitive Long-Evans (Turku/AB; L-E) rats. A comparative analysi…
Absence of lipid peroxidation as determined by ethane exhalation in rats treated with 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD).
1985
The exhalation of ethane is widely used as an indicator of in vivo lipid peroxidation. To test the hypothesis that lipid peroxidative events are involved in the toxicity of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), we administered a lethal dose of TCDD (60 μg/kg), IP to male Sprague Dawley rats (160–180 g) and measured by gas chromatography the exhalation of ethane into the atmosphere of a closed all-glass exposure chamber. TCDD-treated rats exhaled only slightly more ethane than control rats at a single time point 7 days following TCDD administration. Since the exhalation of ethane is the net result of the endogenous production of the gas and its metabolic degradation, the latter was …