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Robinson KJ, Hall AJ, Debier C, Eppe G, Thomé JP, Bennett KA. Persistent Organic Pollutant Burden, Experimental POP Exposure, and Tissue Properties Affect Metabolic Profiles of Blubber from Gray Seal Pups. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13523-13534. [PMID: 30339760 DOI: 10.1021/acs.est.8b04240] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Persistent organic pollutants (POPs) are toxic, ubiquitous, resist breakdown, bioaccumulate in living tissue, and biomagnify in food webs. POPs can also alter energy balance in humans and wildlife. Marine mammals experience high POP concentrations, but consequences for their tissue metabolic characteristics are unknown. We used blubber explants from wild, gray seal ( Halichoerus grypus) pups to examine impacts of intrinsic tissue POP burden and acute experimental POP exposure on adipose metabolic characteristics. Glucose use, lactate production, and lipolytic rate differed between matched inner and outer blubber explants from the same individuals and between feeding and natural fasting. Glucose use decreased with blubber dioxin-like PCBs (DL-PCB) and increased with acute experimental POP exposure. Lactate production increased with DL-PCBs during feeding, but decreased with DL-PCBs during fasting. Lipolytic rate increased with blubber dichlorodiphenyltrichloroethane and its metabolites (DDX) in fasting animals, but declined with DDX when animals were feeding. Our data show that POP burdens are high enough in seal pups to alter adipose function early in life, when fat deposition and mobilization are vital. Such POP-induced alterations to adipose metabolic properties may significantly alter energy balance regulation in marine top predators, with the potential for long-term impacts on fitness and survival.
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Affiliation(s)
- Kelly J Robinson
- Sea Mammal Research Unit, Scottish Oceans Institute , University of St Andrews , St Andrews , Fife KY16 8LB , United Kingdom of Great Britain and Northern Ireland
| | - Ailsa J Hall
- Sea Mammal Research Unit, Scottish Oceans Institute , University of St Andrews , St Andrews , Fife KY16 8LB , United Kingdom of Great Britain and Northern Ireland
| | - Cathy Debier
- Louvain Institute of Biomolecular Science and Technology , Université Catholique de Louvain , Ottignies-Louvain-la-Neuve, Louvain-la-Neuve 1348 , Belgium
| | - Gauthier Eppe
- Center for Analytical Research and Technology (CART), B6c, Department of Chemistry , Université de Liège , Liege 4000 , Belgium
| | - Jean-Pierre Thomé
- Center for Analytical Research and Technology (CART), Laboratory of Animal Ecology and Ecotoxicology (LEAE) , Université de Liège , Liege 4000 , Belgium
| | - Kimberley A Bennett
- Division of Science, School of Science Engineering and Technology , Abertay University , Dundee DD1 1HG , United Kingdom of Great Britain and Northern Ireland
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Martin SA, Campbell JL, Tremblay RT, Fisher JW. Development of a physiologically based pharmacokinetic model for inhalation of jet fuels in the rat. Inhal Toxicol 2011; 24:1-26. [DOI: 10.3109/08958378.2011.631297] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Nagahori H, Matsunaga H, Tomigahara Y, Isobe N, Kaneko H. Metabolism of 2,6-Dichloro-4-(3,3-dichloroallyloxy)phenyl 3-[5-(trifluoromethyl)-2-pyridyloxy]propyl Ether (Pyridalyl) in Rats after Repeated Oral Administration and a Simple Physiologically Based Pharmacokinetic Modeling in Brown and White Adipose Tissues. Drug Metab Dispos 2010; 38:824-32. [DOI: 10.1124/dmd.109.031914] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Clewell RA, Clewell HJ. Development and specification of physiologically based pharmacokinetic models for use in risk assessment. Regul Toxicol Pharmacol 2008; 50:129-43. [DOI: 10.1016/j.yrtph.2007.10.012] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 10/25/2007] [Accepted: 10/27/2007] [Indexed: 10/22/2022]
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Lu Y, Lohitnavy M, Reddy MB, Lohitnavy O, Ashley A, Yang RSH. An updated physiologically based pharmacokinetic model for hexachlorobenzene: incorporation of pathophysiological states following partial hepatectomy and hexachlorobenzene treatment. Toxicol Sci 2006; 91:29-41. [PMID: 16481338 DOI: 10.1093/toxsci/kfj133] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Physiologically based pharmacokinetic (PBPK) modeling is generally used for describing xenobiotic disposition in animals and humans with normal physiological conditions. We describe here an updated PBPK model for hexachlorobenzene (HCB) in male F344 rats with the incorporation of pathophysiological conditions. Two more features contribute to the distinctness of this model from the earlier published versions. This model took erythrocyte binding into account, and a particular elimination process of HCB, the plasma-to-gastrointestinal (GI) lumen passive diffusion (i.e., exsorption), was incorporated. Our PBPK model was developed using data mined from multiple pharmacokinetic studies in the literature, and then modified to simulate HCB disposition under the conditions of our integrated pharmacokinetics/liver foci bioassay. This model included plasma, erythrocytes, liver, fat, rapidly and slowly perfused compartments, and GI lumen. To account for the distinct characteristics of HCB absorption, the GI lumen was split into an upper and a lower part. HCB was eliminated through liver metabolism and the exsorption process. The pathophysiological changes after partial hepatectomy, such as alterations in the liver and body weights and fat volume, were incorporated in our model. With adjustment of the transluminal diffusion-related parameters, the model adequately described the data from the literature and our bioassay. Our PBPK model simulation suggests that HCB absorption and exsorption processes depend on exposure conditions; different exposure conditions dictate different absorption and exsorption rates. This model forms a foundation for our further exploration of the quantitative relationship between HCB exposure and development of preneoplastic liver foci.
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Affiliation(s)
- Yasong Lu
- Quantitative and Computational Toxicology Group, Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523, USA
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Stanton B, Watkins S, German JB, Lasley B. Interaction of estrogen and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) with hepatic fatty acid synthesis and metabolism of male chickens (Gallus domesticus). Comp Biochem Physiol C Toxicol Pharmacol 2001; 129:137-50. [PMID: 11423386 DOI: 10.1016/s1532-0456(01)00195-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study tested the hypothesis that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) antagonizes estrogen-induced hepatic lipid synthesis and metabolism in birds. Twenty immature male chickens (Gallus domesticus) were divided evenly into four groups: (1) vehicle control; (2) estrogen alone (1.0 mg/kg estradiol cypionate injected on three consecutive days); (3) TCDD alone (50 microg/kg injected on the fourth day); and (4) a combination of the estrogen and TCDD treatments. On day 14, liver samples were collected for quantitative fatty acid analysis by capillary gas chromatography. Birds treated with estrogen alone had increased total triacylglyceride concentrations with specific increases in the Delta9 desaturase products 16:1n7, 18:1n7, 18:1n9, and 20:1n9. In addition, estrogen treatment specifically increased 22:6n3 concentrations in both triacylglycerides and phospholipids. However, these increases in Delta9 desaturase products or 22:6n3 did not occur for birds treated with estrogen in combination with TCDD. TCDD and estrogen plus TCDD treatments increased phospholipid concentrations of the diet-derived polyunsaturated fatty acids 18:2n6, 18:3n6, 20:3n6, 18:3n3, and 20:5n3, although only the estrogen plus TCDD group had significantly increased total phospholipids. In cholesterol esters, all three treatments decreased concentrations of total fatty acids, saturated fatty acids, and Delta9 desaturase products compared to the control group.
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Affiliation(s)
- B Stanton
- Institute of Toxicology and Environmental Health (ITEH), University of California Davis, One Shields Ave., 95616, Davis, CA, USA.
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Stanton BJ, El-Sabeawy F, Fang Yang X, Enan E, Lasley BL. Interaction of estrogen and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in immature male chickens (Gallus domesticus). Comp Biochem Physiol C Toxicol Pharmacol 2001; 129:35-47. [PMID: 11369299 DOI: 10.1016/s1532-0456(01)00178-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The interaction of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and estrogen was studied in chickens to more clearly define this relationship in an avian species and its role in the enhanced sensitivity of female chickens to TCDD-induced wasting syndrome. Twenty male chickens (7-9 weeks old) were divided evenly into four groups: control (CTL, received the same volume of vehicle); estrogen-treated (E2, 1 mg/kg estradiol cypionate injections on days 1, 2 and 3); TCDD-treated (TCDD, single 50 microg/kg injection on day 4); and estrogen plus TCDD (E2+TCDD, as above), with measurements taken on day 14. The E2 group compared with the CTL group had decreased comb height (24%), comb length (26%) and adipose tissue (AT) lipoprotein lipase (LPL) activity relative to AT mass (51%), while liver mass and body weight gain were each increased by 28%. The TCDD group had increased liver mass (62%), reduced comb length (17%), and reduced AT LPL activity indexed to AT mass (70%) compared with the CTL group. Finally, the E2+TCDD group had 37% lower body weight gain and 30% larger livers relative to body mass compared with the E2 group, but were not significantly different from the TCDD group. These data show that TCDD antagonized several effects of exogenous estrogen in male chickens, while estrogen enhanced TCDD toxicity in a tissue-specific manner.
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Affiliation(s)
- B J Stanton
- Lasley Laboratory, Institute of Toxicology and Environmental Health, University of California, One Shields Ave., 95616, Davis, CA, USA.
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Abstract
Significant advances have been made in the development of physiologically-based models of dioxin pharmacokinetics (PBPK) in the last 5-6 years. These models incorporate explicit descriptions of biological factors which determine tissue dosimetry of dioxin and include some description of dioxin-mediated pharmacodynamic events. Biological determinants of dioxin disposition include fat solubility, specific and inducible binding in the liver, diffusion-limited tissue distribution and metabolic elimination. PBPK models have been successfully used to predict the dose and time-dependent chemical disposition and protein induction properties of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) over a wide variety of experimental data sets with rodents. The models have also been extended to describe the disposition of a brominated dioxin, 2,3,7,8-tetrabromodibenzo-p-dioxin. As these quantitative descriptions of disposition are more fully refined, particularly with regard to pharmacodynamic descriptions of dioxin-mediated alterations in gene expression, more accurate predictions of tissue dosimetry and tissue responses will be performed across dose, species and related polyhalogenated aromatic hydrocarbons. Accurate, mechanistic dosimetry models will facilitate biologically-based approaches to the human risk assessment of these important and ubiquitous environmental contaminants.
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Affiliation(s)
- L A Buckley
- Eli Lilly and Company, Toxicology Research Laboratories, Greenfield, IN 46140, USA
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Leung HW, Paustenbach DJ. Physiologically based pharmacokinetic and pharmacodynamic modeling in health risk assessment and characterization of hazardous substances. Toxicol Lett 1995; 79:55-65. [PMID: 7570674 DOI: 10.1016/0378-4274(95)03357-q] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Recent advances in physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) modeling have introduced novel approaches for evaluating toxicological problems. Because PBPK models are amenable to extrapolation of tissue dosimetry, they are increasingly being applied to chemical risk assessment. A comprehensive listing of PBPK/PD models for environmental chemicals developed to date is referenced. Salient applications of PBPK/PD modeling to health risk assessments and characterization of hazardous substances are illustrated with examples.
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Affiliation(s)
- H W Leung
- Union Carbide Corporation, Danbury, CT 06817, USA
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Roth WL, Weber LW, Rozman KK. Incorporation of first-order uptake rate constants from simple mammillary models into blood-flow limited physiological pharmacokinetic models via extraction efficiencies. Pharm Res 1995; 12:263-9. [PMID: 7784343 DOI: 10.1023/a:1016239212118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Incorporation of First-Order Uptake Rate Constants from Simple Mammillary Models into Blood-Flow Limited Physiological Pharmacokinetic Models via Extraction Efficiencies. W. L. Roth, L. W. D. Weber, and K. Rozman (1995). Pharm. Res. 263-269. First-order rate constants obtained from classical pharmacokinetic models correspond to mammillary systems in which all of the blood (or plasma) is assumed to be located in a central compartment. In such models the rate at which chemicals are transported out of this pool and into another compartment is the product of the mass of chemical in the central compartment multiplied by a rate constant, which is not limited in magnitude by the blood flow, or the rate at which chemicals from the blood are delivered to the peripheral compartment. Most of the physiologically-based models published to date dispense with some of the information available from mammillary models by assuming that all of the chemical delivered by the flow of blood rapidly equilibrates and can be taken up by the tissue under the control of a "partition coefficient" (Rij = Cj/Ci). We show that the partition coefficient alone does not retain the uptake rate (kji) information available from a classical mammillary model, but that the uptake rate information can be incorporated via unitless extraction efficiency parameters, epsilon j.
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Affiliation(s)
- W L Roth
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City 66160, USA
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