Disease relevance of 4-PeCDF

• The toxicity and disposition of 2,3,4,7,8-pentachlorodibenzofuran (4PeCDF), a ubiquitous and acutely toxic environmental contaminant, was examined in three adult male Rhesus monkeys administered a single iv dose of 34 micrograms (0.1 mumol)/kg [1].
• 4-PeCDF was the most teratogenic with an ED50 of 36 micrograms/kg for cleft palate and 7 micrograms/kg for hydronephrosis [2].
• The potency of 2,3,4,7,8-pentachlorodibenzofuran (P5CDF) and of three defined 2,3,7,8-TCDD-free mixtures of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs) to induce cleft palates in NMRI mice was studied [3].
• 4-PeCDF induced a dose-related decrease in corrected maternal weight gain following treatment on gd 8 and 10, as well as resulted in a concomitant increase in the liver/body weight ratios, first evident at 30 micrograms/kg for all 3 days of exposure [4].

High impact information on 4-PeCDF

• In the rat uterus, the antiestrogenic affects of two potent Ah receptor agonists, 2,3,7,8-TCDD and 2,3,4,7,8-pentachlorodibenzofuran, were comparable at a dose of 80 micrograms/kg, whereas the weaker Ah receptor agonist, 1,2,4,7,8-pentachlorodibenzo-p-dioxin, was relatively inactive at this dose [5].
• To quantify the toxicity of a mixture of three dioxin congeners, we calculated the new relative potencies (REPs) for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), and 2,3,4,7,8- pentachlorodibenzofuran (PeCDF), focusing on their tumor promotion activity [6].
• The other three dose metrics do account for these important factors, and the corresponding RPFs are at least 10-fold lower than the current TEF for 4-PeCDF [7].
• An evaluation for disperse emissions of PeCDF (2,3,4,7,8-pentachlorodibenzofuran, CAS# 5120731-4) suggests reasonable agreement with monitoring data for most impact pathways with both versions of the model, but that the generic vegetation models for estimating contaminant concentrations in agricultural produce require improvement [8].
• 4-PeCDF, PeCDD and PCB 126 showed higher liver affinity than TCDD [9].

Chemical compound and disease context of 4-PeCDF

• In vitro analysis of polychlorinated biphenyls (PCBs) and 2,3,4,7,8-pentachlorodibenzofuran (PCDF) cellular toxicity in PLC/PRF/5 cell proliferation--the effect of ursodeoxycholic acid, inchin-gorei-san and shou-saiko-to on cell toxicity [10].

Biological context of 4-PeCDF

• Pregnant mice were treated with 10 ml/kg corn oil containing no PCDFs, 4-PeCDF (0-30 micrograms/kg), HCDF (0-300 micrograms/kg), or a combination of the two on gestation Days 10-13, followed by necropsy on gestation Day 18 [11].
• The recent National Toxicology Program (NTP) cancer bioassays for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF) permit a reevaluation of the current TEF value of 4-PeCDF [7].
• 4-PeCDF is highly sequestered in hepatic tissue and when the relative potency was estimated based on tissue concentration, its potency for skin enzyme induction increased [12].
• In this study we have investigated the induction of oxidative stress in hepatic and brain tissues of rats after subchronic (13 weeks) exposure to TCDD and two of its congeners, namely 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) and 3,3',4,4',5-pentachlorobiphenyl (PCB126) [13].
• On a body-burden basis, PCB 126 and 4-PeCDF were 2- to 3-fold and 10- to 12-fold less potent than predicted based on the WHO TEFs, respectively, while the TEQ mixture was approximately 3- to 5-fold less potent than predicted by the TEFs [14].

Anatomical context of 4-PeCDF

• Metabolism of benzo(a)pyrene by lung microsomes from rabbits pretreated with polychlorinated biphenyls and 2,3,4,7,8-pentachlorodibenzofuran [15].
• Two forms of cytochrome P-450 (P-450) from liver microsomes of hamsters treated with 2,3,4,7,8-pentachlorodibenzofuran (PenCDF), which possesses the potent acute toxicity and 3-methylcholanthrene (MC)-type inducing ability of liver microsomal monooxygenases in animals, were purified and characterized [16].

Associations of 4-PeCDF with other chemical compounds

• In order to examine the potential for systemic exposure following dermal exposure, the absorption, distribution, and elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlorodibenzofuran (1PeCDF), and 2,3,4,7,8-pentachlorodibenzofuran (4PeCDF) were evaluated in male F344 rats [17].
• The major contribution to total TEQ in the majority of cases came from 2,3,7,8-tetrachlorodibenzofuran owing to its relatively higher levels and 2,3,4,7,8-pentachlorodibenzofuran because of its TEF of 0 [18].
• Teratogenic potency of 2,3,4,7,8-pentachlorodibenzofuran and of three mixtures of polychlorinated dibenzo-p-dioxins and dibenzofurans in mice. Problems with risk assessment using TCDD toxic-equivalency factors [3].

Gene context of 4-PeCDF

• With TCDD as the reference standard, relative potency (REP) estimates were derived from ratios of the BMD10 estimates for PCB 126, 4-PeCDF, and for the toxic equivalent (TEQ) mixture [14].
• We investigated the cell toxicity of polychlorinated biphenyls (PCBs) and 2,3,4,7,8-pentachlorodibenzofuran (PCDF) as an indicator of the quantity of m-RNA, which synthesizes the HBV core antigen region, and secreting protein, which is an HBV surface antigen in PLC/PRF/5 cells [10].

References