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Dixon D, Sleight S, Aust S, Rezabek M. Tumor-Promoting, Initiating, and Hepatotoxic Effects of 3,4,3',4'-Tetrabromobiphenyl (34-TBB) in Rats. ACTA ACUST UNITED AC 2016. [DOI: 10.3109/10915818809019543] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Female, 180–200 g Sprague-Dawley rats were used to determine if 3,4,3',4'-tetrabromobi-phenyl (34-TBB) is a promoter or initiator in a two-stage hepatocarcinogenesis assay. To test for promotion, rats were partially hepatectomized (PH) 24 hr before initiation (day 1) with 10 mg of diethylnitrosamine (DEN)/kg body weight given intraperitoneally (IP). Thirty days later, promotion was with 34-TBB (0.1,1 or 5 mg/kg) or phenobarbital (PB) (500 mg/kg) in diets for 180 days. To test for initiation, rats were PH and were initiated on day 1 with 34-TBB (1, 5, or 10 mg/kg) orally or DEN (10 mg/kg) IP. On day 31, promotion was with 500 mg of PB/kg of diet for 180 days. Noninitiated and non-PH rats were used to assess the histological and ultrastructural tissue changes associated with administration of 34-TBB in the diet for 180 days. Tumor promotion-initiation were assessed by counting and measuring hepatic enzyme-altered foci (EAF) with gamma-glutamyl transpeptidase (GGT) activity. Congener 34-TBB acts as a promoter in experimental hepatocarcinogenesis in rats, as evidenced by increased numbers of GGT-positive EAF. Also, 34-TBB may have initiation potential, as suggested by increased numbers of EAF in rats initiated with 34-TBB and promoted by PB. Dietary administration of 34-TBB for 180 days is not severely toxic in rats, as evidenced by mild histological and ultrastructural changes and minimal alterations in organ and body weights. Congener 34-TBB does not accumulate in liver and adipose tissue of rats.
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Affiliation(s)
- D. Dixon
- Department of Pathology Michigan State University East Lansing, MI 48824
| | - S.D. Sleight
- The Rockefeller University, Laboratory Animal Research Center, New York, New York
| | - S.D. Aust
- Department of Biochemistry, Michigan State University, East Lansing, Michigan
| | - M.S. Rezabek
- The Rockefeller University, Laboratory Animal Research Center, New York, New York
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Aust SD. Bioremediation monitoring. ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:A444. [PMID: 16002359 PMCID: PMC1257674 DOI: 10.1289/ehp.113-a444a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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3
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YOSHIKAWA H, MORITA H, TAKIZAWA T, SHIRAI M, AKAHORI F, IMANO N, NAKAAKI K, SAKATA R, YOSHIMURA T. Electron paramagnetic resonance analysis of liver and serum in Sprague-Dawley rats exposed subchronically to coplanar pentachlorobiphenyl-congener 3,3',4,4',5. Anim Sci J 2002. [DOI: 10.1046/j.1344-3941.2002.00037.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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4
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Nakata H, Tanabe S, Tatsukawa R, Amano M, Miyazaki N, Petrov EA. Bioaccumulation profiles of polychlorinated biphenyls including coplanar congeners and possible toxicological implications in Baikal seal (Phoca sibirica). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 1997; 95:57-65. [PMID: 15093474 DOI: 10.1016/s0269-7491(96)00092-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/1996] [Accepted: 07/23/1996] [Indexed: 05/24/2023]
Abstract
Isomer specific concentrations of individual polychlorinated biphenyls (PCBs) including toxic non-ortho (IUPAC 77, 126, 169), mono-ortho (105, 118, 156) and di-ortho (137, 138, 153, 180) coplanar congeners were determined in the blubber of 40 Baikal seals (Phoca sibirica) and as their fish diet collected from Lake Baikal, Siberia. Residue levels of total PCBs in Baikal seals were noticeably high and comparable to those reported for seals from the North Sea, suggesting the recent usage of this compound in the watershed of Lake Baikal. Non-, mono-, and di-ortho coplanar congeners were also detected in Baikal seals and fish. An approach to estimate bioaccumulation profiles of PCB congeners revealed that the non-ortho PCBs, IUPAC 77, 126 and 169 seemed to be less persistent than other congeners. Furthermore, selective biotransformation of PCB congeners having either meta-para vicinal H atoms or both adjacent chlorinated meta-para and ortho-meta positions has been suggested. Comparison of 2,3,7,8-TCDD toxic equivalents (TEQ) of non-, mono- and di-ortho coplanar congeners in Baikal seals with those for other marine mammals suggested higher enrichment of mono-ortho congeners, particularly IUPAC 105 and 118, which contributed significantly to the total TEQs in Baikal seals. Results imply that the TCDD-like toxicity is relatively serious in Baikal seals, because of the enrichment of these toxic PCB congeners in tissues.
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Affiliation(s)
- H Nakata
- Department of Life Environment Conservation, Ehime University, Tarumi 3-5-7, Matsuyama 790, Japan
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Pijnenburg AM, Everts JW, de Boer J, Boon JP. Polybrominated biphenyl and diphenylether flame retardants: analysis, toxicity, and environmental occurrence. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1995; 141:1-26. [PMID: 7886253 DOI: 10.1007/978-1-4612-2530-0_1] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Data on two classes of brominated polyaromatic flame retardants are reviewed with emphasis on analytical aspects, occurrence, fate, and toxicity in the environment. Concentrations of brominated fire retardants are quantified as equivalents of commercial mixtures. Because different congeners behave differently in the environment and show large differences in toxicity, future studies would benefit from the availability of analytical standards of individual congeners. The main environmental properties and mechanisms of toxicity of the PBBs and PBDEs are similar to those of the structurally related PCBs and dibenzodioxins. Although the present concentrations of brominated fire retardants do not yet appear to represent a major environmental risk in marine food chains, their replacement by environmentally less harmful alternatives is recommended.
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Affiliation(s)
- A M Pijnenburg
- National Institute for Coastal and Marine Management (RIKZ), Ministry of Transport, Public Works and Water Management, The Hague, The Netherlands
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Van den Berg M, De Jongh J, Poiger H, Olson JR. The toxicokinetics and metabolism of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and their relevance for toxicity. Crit Rev Toxicol 1994; 24:1-74. [PMID: 8172651 DOI: 10.3109/10408449409017919] [Citation(s) in RCA: 285] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This article reviews the present state of the art regarding the toxicokinetics and metabolism of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). The absorption, body distribution, and metabolism can vary greatly between species and also may depend on the congener and dose. In biota, the 2,3,7,8-substituted PCDDs and PCDFs are almost exclusively retained in all tissue types, preferably liver and fat. This selective tissue retention and bioaccumulation are caused by a reduced rate of biotransformation and subsequent elimination of congeners with chlorine substitution at the 2,3,7, and 8 positions. 2,3,7,8-Substituted PCDDs and PCDFs also have the greatest toxic and biological activity and affinity for the cytosolic arylhydrocarbon (Ah)-receptor protein. The parent compound is the causal agent for Ah-receptor-mediated toxic and biological effects, with metabolism and subsequent elimination of 2,3,7,8- substituted congeners representing a detoxification process. Congener-specific affinity of PCDDs and PCDFs for the Ah-receptor, the genetic events following receptor binding, and toxicokinetics are factors that contribute to the relative in vivo potency of an individual PCDD or PCDF in a given species. Limited human data indicate that marked species differences exist in the toxicokinetics of these compounds. Thus, human risk assessment for PCDDs and PCDFs needs to consider species-, congener-, and dose-specific toxicokinetic data. In addition, exposure to complex mixtures, including PCBs, has the potential to alter the toxicokinetics of individual compounds. These alterations in toxicokinetics may be involved in some of the nonadditive toxic or biological effects that are observed after exposure to mixtures of PCDDs or PCDFs with PCBs.
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Affiliation(s)
- M Van den Berg
- Research Institute of Toxicology, Utrecht University, The Netherlands
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Brunström B, Andersson L. Toxicity and 7-ethoxyresorufin O-deethylase-inducing potency of coplanar polychlorinated biphenyls (PCBs) in chick embryos. Arch Toxicol 1988; 62:263-6. [PMID: 3149181 DOI: 10.1007/bf00332485] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The toxicities of the coplanar polychlorinated biphenyls 3,3',4,4'-tetrachlorobiphenyl (TCB), 3,3',4,4',5-pentachlorobiphenyl (PeCB) and 3,3',4,4',5,5'-hexachlorobiphenyl (HCB) were compared in a 72-h study on chick embryos. The substances were injected into the air sacs of hens' eggs preincubated for 7 days. Mortality was measured 72 h later and corresponding LD50 values were calculated. The rank order of toxicity was PeCB greater than TCB greater than HCB. Using the same injection procedure, the potencies of these chlorobiphenyls with regard to their induction of hepatic 7-ethoxyresorufin O-deethylase activity were compared. The ranking order of the substances as inducers was the same as their order when ranked according to toxicity. The three coplanar chlorobiphenyls were considerably more toxic and potent as inducers than the nonplanar 2,2',4,4',5,5'-hexachlorobiphenyl. In a 2-week toxicity study, PeCB and HCB were injected into the yolks of hens' eggs preincubated for 4 days. PeCB was about 50-fold more potent than HCB in causing embryonic death. Both substances caused abnormalities, including edema, liver lesions, microphthalmia and beak deformities.
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Affiliation(s)
- B Brunström
- Department of Zoophysiology, Uppsala University, Sweden
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van den Berg KJ, Zurcher C, Brouwer A, van Bekkum DW. Chronic toxicity of 3,4,3',4'-tetrachlorobiphenyl in the marmoset monkey (Callithrix jacchus). Toxicology 1988; 48:209-24. [PMID: 3124295 DOI: 10.1016/0300-483x(88)90102-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cotton top marmoset monkeys (Callithrix jacchus) were orally dosed with 3, 1, 0.1 or 0 mg 3,4,3',4'-tetrachlorobiphenyl (TCB)/kg body weight twice per week for 18-23 weeks. Severe toxicity occurred in the highest dose group. Clinical signs of toxicity were a rapid decrease in body weight, alopecia, abnormal nail growth, nodular enlargement of the nipple area and scaly skin. Haematological analysis of peripheral blood revealed mild leukocytosis and anemia. Biochemical alterations observed were elevated triglyceride levels and cholesterol levels. Histopathology revealed dose dependent changes in a variety of tissues. Squamous metaplasia was found in skin and adnexa as well as in salivary glands. In the stomach, parietal cells were decreased and mucus producing cells were increased. The duodenal mucosa was hyperplastic. Ovaries showed an absence of corpora lutea. In the thyroid follicular cell hyperplasia and hypertrophy were noted. Toxicity was less severe in marmoset monkeys dosed with 1 mg TCB/kg, while minor toxic effects were observed in the animals dosed with 0.1 mg TCB/kg. The marmoset monkey appears to be less sensitive to the toxic action of TCB than the rhesus monkey. The pattern of histological and biochemical changes induced by TCB in marmoset monkeys is comparable to that described in humans and in other primate species exposed to PCBs. The marmoset monkey model may be valuable for investigations on human-related toxicity of PCBs.
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Powers RH, Gilbert LC, Aust SD. The effect of 3,4,3',4'-tetrachlorobiphenyl on plasma retinol and hepatic retinyl palmitate hydrolase activity in female Sprague-Dawley rats. Toxicol Appl Pharmacol 1987; 89:370-7. [PMID: 3111014 DOI: 10.1016/0041-008x(87)90156-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The Effect of 3,4,3',4'-Tetrachlorobiphenyl on Plasma Retinol and Hepatic Retinyl Palmitate Hydrolase Activity in Female Sprague-Dawley Rats. Powers, R.H., Gilbert, L.C., and Aust, S.D. (1987). Toxicol Appl. Pharmacol. 89, 370-377. A single ip dose of 1, 5, or 15 mg/kg 3,4,3',4'-tetrachlorobiphenyl (TCB) caused a dose-dependent depression of plasma retinol levels 24 hr after treatment of female Sprague-Dawley rats. The loss of plasma retinol appeared to be a function of depressed levels of the retinol-retinol-binding protein (RBP)-transthyretin ternary complex. No free retinol-RBP was observed in plasma from treated animals. Hepatic retinyl palmitate hydrolase (RPH) activity was also depressed and highly and positively correlated to the plasma retinol levels. TCB was determined to be a noncompetitive inhibitor of partially purified RPH with a KI of 91 microM. Incubation of TCB with liver microsomes and NADPH decreased the inhibition of RPH. Doses of either 2,4,5,2',4',5'-hexachlorobiphenyl (HCB) or 3,4,5,3',4',5'-HCB equimolar to the 15 mg/kg TCB dose failed to cause a similar depression of plasma retinol in treated female rats. We conclude that, unlike other polychlorinated biphenyl congeners, TCB causes a depression of plasma retinol by inhibition of hepatic RPH.
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Tanabe S, Kannan N, Subramanian A, Watanabe S, Tatsukawa R. Highly toxic coplanar PCBs: occurrence, source, persistency and toxic implications to wildlife and humans. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 1987; 47:147-163. [PMID: 15092716 DOI: 10.1016/0269-7491(87)90044-3] [Citation(s) in RCA: 106] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/1987] [Accepted: 04/30/1987] [Indexed: 05/24/2023]
Abstract
Isomer-specific determinations of PCB congeners in a wide variety of animal species such as fish, marine mammals (whale, dolphin and porpoise) and terrestrial mammals (dog, cat and human) revealed the environmental occurrence of highly toxic coplanar 3,3',4,4'-tetrachlorobiphenyl (T(4)CB), 3,3',4,4',5-pentachlorobiphenyl (P(5)CB) and 3,3',4,4',5,5'-hexachlorobiphenyl (H(6)CB) within a range of few pg g(-1) to several ten ng g(-1) in fat tissues (except fish) on a wet weight basis. Detection of these toxic residues in wild specimens collected from remote areas such as the North Pacific suggests the already widespread distribution of coplanar PCBs as in the case of general PCB pollution. The clear positive correlations between concentrations of total PCBs and each of the three coplanar PCBs obtained in all mammals analysed suggest that the sources of coplanar PCB contamination to the environment are mainly commercial PCB preparations. Comparison of the composition of three toxic coplanar PCBs in commercial PCB mixtures and in the various animals indicates the relative metabolisability of these congeners as follows: 3,3',4,4'-T4CB>3,3',4,4',5-P5CB>3,3',4,4',5,5'-H6CB. Moreover, marine mammals seem to have lower potency to metabolise the coplanar PCBs in comparison with terrestrial mammals. In human adipose tissues, the concentrations of coplanar PCBs were found to be much higher than 2,3,7,8-tetrachlorodibenzo-p-dioxin (T(4)CDD), 2,3,4,7,8-pentachlorodibenzofuran (P(5)CDF) and other toxic congeners. 'T(4)CDD-equivalent' analysis based on the enzyme induction potencies and the residues of these toxic chemicals indicates that 3,3',4,4',5-P(5)CB may impose a greater toxic threat than dioxins and furans to the humans and probably to wildlife also.
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Affiliation(s)
- S Tanabe
- Department of Environment Conservation, Ehime University, Tarumi 3-5-7, Matsuyama 790, Japan
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Lubet RA, Lemaire BN, Avery D, Kouri RE. Induction of immunotoxicity in mice by polyhalogenated biphenyls. Arch Toxicol 1986; 59:71-7. [PMID: 3092783 DOI: 10.1007/bf00286726] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Acute administration of Aroclor-1254 (500 mg/kg) or 3,4,5,3',4',5'-hexabromobiphenyl (HBB) (2-6 mg/kg) IP, profoundly inhibited the plaque forming response to subsequent challenge with sheep erythrocytes in Ah locus positive (C57Bl/6N or B6C3F1N) mice. These studies showed: the immunotoxicity results paralleled enzyme induction results insofar as HBB was approximately 100 times more potent than Aroclor 1254; neither Aroclor nor HBB treatment caused significant induction in the Ah locus negative DBA/2N mice; when B6C3F1 mice were challenged with sheep red blood cells (SRBC) 6 or 16 weeks post Aroclor 1254 treatment, substantial recovery of a PFC response was observed; when these compounds were administered to older (76-week-old) (B6C3F1 mice, severe depression of a PFC response was observed. In contrast to its profound depression of a PFC response, Aroclor-1254 (up to 1250 mg/kg) caused slight increases in lymphocyte proliferation induced by either T or B cell mitogens. A single 500 mg/kg dose of Aroclor-1254 also suppressed the ability of recipient B6C3F1 animals to reject a challenge with either the syngenic fibrosarcoma (PYB6) or the gram negative pathogen (Listeria monocytogenes).
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Mills RA, Millis CD, Dannan GA, Guengerich FP, Aust SD. Studies on the structure-activity relationships for the metabolism of polybrominated biphenyls by rat liver microsomes. Toxicol Appl Pharmacol 1985; 78:96-104. [PMID: 2994255 DOI: 10.1016/0041-008x(85)90309-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The in vitro metabolism of polybrominated biphenyl (PBB) congeners by cytochrome P-450-dependent monooxygenases was investigated using hepatic microsomes isolated from immature male rats pretreated with 3-methylcholanthrene (MC) or phenobarbital (PB). MC pretreatment increased the NADPH-dependent microsomal metabolism of pure PBB congeners which possessed adjacent nonhalogenated ortho and meta carbons on at least one ring. 4,4'-Dibromobiphenyl (-DBB) was metabolized at the fastest rate, followed by 3,4,4'-tribromobiphenyl, 3,4,3',4'-tetrabromobiphenyl (-TBB), 2,3,3',4'-TBB, 2,5,3',4'-TBB, and 2,4,2',5'-TBB in decreasing order. It appeared that further bromination prevented metabolism since 2,4,5,3',4'-pentabromobiphenyl (-PBB), 2,3,4,2',4',5'-hexabromobiphenyl (-HBB), and 2,3,4,5,3'.4'-HBB were not metabolized although they possess adjacent nonhalogenated ortho and meta carbons. PB pretreatment increased in vitro rat hepatic microsomal metabolism of PBB congeners which possessed adjacent nonhalogenated meta and para carbons on at least one ring. 2,2'-DBB was metabolized at the fastest rate, followed by 2,4,2',5'-TBB, 2,5,2',5'-TBB, 2,3,3',4'-TBB, 2,5,3',4'-TBB, and 2,4,5,2',5'-PBB in decreasing order. The results suggest that the rates of metabolism of PBB congeners are dependent upon the positions of bromine and the form of cytochrome P-450 induced. In vitro rates of metabolism of 3,4,3',4'-TBB using hepatic microsomes isolated from rats pretreated with either 3,4,5,3',4',5'-HBB or 3,4,3',4'-TBB were also investigated. There was good correlation between the rates of 3,4,3',4'-TBB metabolism, induction of microsomal ethoxyresorufin-O-deethylase activity, and specific content of MC-inducible cytochrome P-450 (P-450 beta NF-B). The results suggest that the isozyme P-450 beta NF-B is responsible for the metabolism of 3,4,3',4'-TBB.
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