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Gonnabathula P, Choi MK, Li M, Kabadi SV, Fairman K. Utility of life stage-specific chemical risk assessments based on New Approach Methodologies (NAMs). Food Chem Toxicol 2024; 190:114789. [PMID: 38844066 DOI: 10.1016/j.fct.2024.114789] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 05/17/2024] [Accepted: 06/03/2024] [Indexed: 06/17/2024]
Abstract
The safety assessments for chemicals targeted for use or expected to be exposed to specific life stages, including infancy, childhood, pregnancy and lactation, and geriatrics, need to account for extrapolation of data from healthy adults to these populations to assess their human health risk. However, often adequate and relevant toxicity or pharmacokinetic (PK) data of chemicals in specific life stages are not available. For such chemicals, New Approach Methodologies (NAMs), such as physiologically based pharmacokinetic (PBPK) modeling, biologically based dose response (BBDR) modeling, in vitro to in vivo extrapolation (IVIVE), etc. can be used to understand the variability of exposure and effects of chemicals in specific life stages and assess their associated risk. A life stage specific PBPK model incorporates the physiological and biochemical changes associated with each life stage and simulates their impact on the absorption, distribution, metabolism, and elimination (ADME) of these chemicals. In our review, we summarize the parameterization of life stage models based on New Approach Methodologies (NAMs) and discuss case studies that highlight the utility of a life stage based PBPK modeling for risk assessment. In addition, we discuss the utility of artificial intelligence (AI)/machine learning (ML) and other computational models, such as those based on in vitro data, as tools for estimation of relevant physiological or physicochemical parameters and selection of model. We also discuss existing gaps in the available toxicological datasets and current challenges that need to be overcome to expand the utility of NAMs for life stage-specific chemical risk assessment.
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Affiliation(s)
- Pavani Gonnabathula
- Division of Biochemical Toxicology, National Center for Toxicological Research (NCTR), US Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Me-Kyoung Choi
- Division of Biochemical Toxicology, National Center for Toxicological Research (NCTR), US Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Miao Li
- Division of Biochemical Toxicology, National Center for Toxicological Research (NCTR), US Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Shruti V Kabadi
- Center for Food Safety and Applied Nutrition (CFSAN), US Food and Drug Administration (FDA), College Park, MD, 20740, USA
| | - Kiara Fairman
- Division of Biochemical Toxicology, National Center for Toxicological Research (NCTR), US Food and Drug Administration (FDA), Jefferson, AR, 72079, USA.
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2
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Marchese MJ, Zhu T, Hawkey AB, Wang K, Yuan E, Wen J, Be SE, Levin ED, Feng L. Prenatal and perinatal exposure to Per- and polyfluoroalkyl substances (PFAS)-contaminated drinking water impacts offspring neurobehavior and development. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170459. [PMID: 38290673 PMCID: PMC10923173 DOI: 10.1016/j.scitotenv.2024.170459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/01/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants ubiquitous in the environment and humans. In-utero PFAS exposure is associated with numerous adverse health impacts. However, little is known about how prenatal PFAS mixture exposure affects offspring's neurobehavioral function. This study aims to determine the causal relationship between in-utero PFAS mixture exposure and neurobehavioral changes in Sprague-Dawley rat offspring. Dams were exposed via drinking water to the vehicle (control), an environmentally relevant PFAS mixture, or a high-dose PFAS mixture. The environmentally relevant mixture was formulated to resemble measured tap water levels in Pittsboro, NC, USA (10 PFAS compounds; sum PFAS =758.6 ng/L). The high-dose PFAS load was 3.8 mg/L (5000×), within the range of exposures in the experimental literature. Exposure occurred seven days before mating until birth. Following exposure to PFAS-laden water or the vehicle during fetal development, neurobehavioral toxicity was assessed in male and female offspring with a battery of motor, cognitive, and affective function tests as juveniles, adolescents, and adults. Just before weaning, the environmentally relevant exposure group had smaller anogenital distances compared to the vehicle and high-dose groups on day 17, and males in the environmentally relevant exposure group demonstrated lower weights than the high-dose group on day 21 (p < 0.05). Reflex development delays were seen in negative geotaxis acquisition for both exposure groups compared to vehicle-exposed controls (p = 0.009). Our post-weaning behavioral measures of anxiety, depression, and memory were not found to be affected by maternal PFAS exposure. In adolescence (week five) and adulthood (week eight), the high PFAS dose significantly attenuated typical sex differences in locomotor activity. Maternal exposure to an environmentally relevant PFAS mixture produced developmental delays in the domains of pup weight, anogenital distance, and reflex acquisition for rat offspring. The high-dose PFAS exposure significantly decreased typical sex differences in locomotor activity.
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Affiliation(s)
| | - Tianyi Zhu
- Duke University Global Health Institute, Durham, NC, USA
| | - Andrew B Hawkey
- Department of Biomedical Sciences, Midwestern University, Downers Grove, IL, USA
| | | | - Emi Yuan
- Duke University, Durham, NC, USA
| | | | | | - Edward D Levin
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - Liping Feng
- Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC, USA.
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Hussain A, Kumar S, Kaul G. Postnatal distribution of ZnO nanoparticles to the breast milk through oral route and their risk assessment for breastfed rat offsprings. Hum Exp Toxicol 2020; 39:1318-1332. [PMID: 32347117 DOI: 10.1177/0960327120921441] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Various studies in rodents have shown that nanoparticles are transferred to the breast milk. Under the present study, lactating Wistar rats were repetitively gavaged 5, 25, and 50 mg/kg bw of zinc oxide nanoparticles (ZnO-NPs) and 50 mg kg-1 bw of bulk zinc oxide (bZnO) for 19 days after parturition. The results showed that ZnO-NPs were absorbed in the small intestine of dams and distributed to the liver. Furthermore, ZnO-NPs were distributed to the intestine and liver of rat pups through dam's milk. No significant change in body weight was observed in the dams treated with ZnO-NPs or bZnO and their offsprings as compared to the control group. The spleen weight significantly increased in the rat dams treated with 50 mg kg-1 of ZnO-NPs. ZnO-NPs were mostly excreted through feces. The levels of liver cytochrome P450 reductase and serum total antioxidant capacity significantly decreased in the rat dams treated with ZnO-NPs (50 mg kg-1) and their offsprings. The levels of serum cytokines (tumor necrosis factor-alpha and interleukin-1 beta) and liver injury marker enzymes (alanine aminotransferase and aspartate aminotransferase) significantly increased in the rat dams treated with ZnO-NPs (25 and 50 mg kg-1) and their offsprings. The level of immunoglobulin A secretion in the intestinal fluid of rat dams and their offsprings is significantly increased by increasing the dose of ZnO-NPs. Histopathology of intestine and liver of offsprings whose rat dams were treated with ZnO-NPs (50 mg kg-1) showed gross pathological changes. These results provide information for the safety evaluation of ZnO-NPs use during lactation. In conclusion, a dose-dependent postnatal transfer of ZnO-NPs is hazardous to the breastfed offsprings.
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Affiliation(s)
- A Hussain
- N.T. Lab-I, Division of Animal Biochemistry, ICAR-National Dairy Research Institute, Karnal, Haryana, India
| | - S Kumar
- N.T. Lab-I, Division of Animal Biochemistry, ICAR-National Dairy Research Institute, Karnal, Haryana, India
| | - G Kaul
- N.T. Lab-I, Division of Animal Biochemistry, ICAR-National Dairy Research Institute, Karnal, Haryana, India
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Arts J, Beekhuijzen M. Is there a rationale for direct dosing of chemicals to nursing pups in the EOGRTS (OECD 443)? Regul Toxicol Pharmacol 2020; 113:104641. [PMID: 32165176 DOI: 10.1016/j.yrtph.2020.104641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 03/05/2020] [Accepted: 03/07/2020] [Indexed: 11/26/2022]
Abstract
In OECD guideline 443 - Extended One Generation Reproductive Toxicity Study (EOGRTS) - to be used for testing industrial and agrochemicals, it has been indicated that careful consideration of benefits and disadvantages should be made prior to conducting direct-dosing studies in nursing pups. Nursing pups will not be directly dosed in dietary and drinking water studies whereas in oral gavage studies this possibility exists. Besides the risk of intubation trauma and overdosing due to direct exposure and exposure via the mother's milk, direct dosing could lead to a different hazard assessment of chemicals depending on the choice of the route of administration. In addition, in case of industrial and agrochemicals used in industrial or professional settings only, there will never be direct exposure of newborns. Moreover, direct dosing of nursing pups is an artificial, non-physiological, route of exposure and as such it would hamper risk assessment. It should therefore only be considered in exceptional cases and justified on a case-by-case approach.
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Affiliation(s)
- Josje Arts
- Nouryon Chemicals BV, Velperweg 76, 6824 BM, Arnhem, Netherlands.
| | - Manon Beekhuijzen
- Charles River, Hambakenwetering 7, 5231 DD, 's-Hertogenbosch, Netherlands
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Beekhuijzen M, Barentsen H, Marsden E, Zmarowski A, Aujoulat M, Picut C, Sloter E. Implementing the extended one-generation reproductive toxicity study (EOGRTS): important points to consider. Crit Rev Toxicol 2016; 46:332-47. [DOI: 10.3109/10408444.2015.1137863] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Lin Z, Fisher JW, Wang R, Ross MK, Filipov NM. Estimation of placental and lactational transfer and tissue distribution of atrazine and its main metabolites in rodent dams, fetuses, and neonates with physiologically based pharmacokinetic modeling. Toxicol Appl Pharmacol 2013; 273:140-58. [DOI: 10.1016/j.taap.2013.08.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/07/2013] [Accepted: 08/10/2013] [Indexed: 11/27/2022]
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Marty MS, Neal BH, Zablotny CL, Yano BL, Andrus AK, Woolhiser MR, Boverhof DR, Saghir SA, Perala AW, Passage JK, Lawson MA, Bus JS, Lamb JC, Hammond L. An F1-extended one-generation reproductive toxicity study in Crl:CD(SD) rats with 2,4-dichlorophenoxyacetic acid. Toxicol Sci 2013; 136:527-47. [PMID: 24072463 PMCID: PMC3858197 DOI: 10.1093/toxsci/kft213] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) was assessed for systemic toxicity, reproductive toxicity, developmental neurotoxicity (DNT), developmental immunotoxicity (DIT), and endocrine toxicity. CD rats (27/sex/dose) were exposed to 0, 100, 300, 600 (female), or 800 (male) ppm 2,4-D in diet. Nonlinear toxicokinetic behavior was shown at high doses; the renal clearance saturation threshold for 2,4-D was exceeded markedly in females and slightly exceeded in males. Exposure was 4 weeks premating, 7 weeks postmating for P1 males and through lactation for P1 females. F1 offspring were examined for survival and development, and at weaning, pups were divided in cohorts, by sex and dose, and by systemic toxicity (10), DNT (10), DIT (20), and reproductive toxicity (≥ 23). Remaining weanlings were evaluated for systemic toxicity and neuropathology (10–12). Body weight decreased during lactation in high-dose P1 females and in F1 pups. Kidney was the primary target organ, with slight degeneration of proximal convoluted tubules observed in high-dose P1 males and in high-dose F1 males and females. A slight intergenerational difference in kidney toxicity was attributed to increased intake of 2,4-D in F1 offspring. Decreased weanling testes weights and delayed preputial separation in F1 males were attributed to decreased body weights. Endocrine-related effects were limited to slight thyroid hormone changes and adaptive histopathology in high-dose GD 17 dams seen only at a nonlinear toxicokinetic dose. 2,4-D did not cause reproductive toxicity, DNT, or DIT. The “No Observed Adverse Effect Level” for systemic toxicity was 300 ppm in both males (16.6mg/kg/day) and females (20.6mg/kg/day), which is approximately 6700- to 93 000-fold higher than that reported for 2,4-D exposures in human biomonitoring studies.
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Affiliation(s)
- Mary Sue Marty
- * Toxicology and Environmental Research & Consulting, The Dow Chemical Company, Midland, Michigan
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Ulbrich B. Reproductive toxicity risk assessment for pesticides. Methods Mol Biol 2013; 947:545-574. [PMID: 23138925 DOI: 10.1007/978-1-62703-131-8_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Human health risk assessment for pesticides is based mainly on animal studies submitted by the applicant and aims to determine safe exposure levels for operators (farmers and agricultural workers) and consumers of all age groups. Critical effects, including those resulting from reproductive toxicity, are identified during hazard assessment from an evaluation of all studies in the toxicity package. Reproductive or developmental effects are considered critical if they are more severe or occur at lower doses than other toxicities. Reference values for human exposure are then derived from No Adverse Effect Levels for the relevant critical effects by applying safety factors. This paper describes methods and caveats applicable to the evaluation of prenatal toxicity and two-generation studies from the view of a regulator, stressing the importance of individual litter data and the relationship between different endpoints.
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Affiliation(s)
- Beate Ulbrich
- Abteilung Chemikaliensicherheit, Fg 62 Toxikologie der Pestizide und Biozide, Bundesinstitut für Risikobewertung, Berlin, Germany.
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Loccisano AE, Campbell JL, Butenhoff JL, Andersen ME, Clewell HJ. Evaluation of placental and lactational pharmacokinetics of PFOA and PFOS in the pregnant, lactating, fetal and neonatal rat using a physiologically based pharmacokinetic model. Reprod Toxicol 2011; 33:468-490. [PMID: 21872655 DOI: 10.1016/j.reprotox.2011.07.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 06/25/2011] [Accepted: 07/22/2011] [Indexed: 11/24/2022]
Abstract
Perfluoroalkyl carboxylates and sulfonates (PFAAs) have many consumer and industrial applications. Developmental toxicity studies in animals have raised concern about potential developmental effects of PFOA and PFOS in humans. We have developed PBPK models for PFAAs in the rat to help define a relationship between external dose, internal tissue concentrations, and observed adverse effects, and to understand how physiological changes that occur during gestation and lactation affect tissue distribution of PFAAs in the mother, fetus, and neonate. The models developed here expand upon a PBPK model for PFAAs in the adult female rat, and are consistent with available PK data. These models, along with the adult rat PFAA models, published in the companion paper, will help address concerns about possible health effects due to PFAA exposure in the fetus and neonate and will be useful in comparing PK across life stages.
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Affiliation(s)
- Anne E Loccisano
- Center for Human Health Assessment, The Hamner Institutes for Health Sciences, 6 Davis Drive, P.O. Box 12137, Research Triangle Park, NC 27709, United States.
| | - Jerry L Campbell
- Center for Human Health Assessment, The Hamner Institutes for Health Sciences, 6 Davis Drive, P.O. Box 12137, Research Triangle Park, NC 27709, United States
| | - John L Butenhoff
- 3M Medical Department, Corporate Toxicology, 3M Center 220-2E-02, St. Paul, MN 55144, United States
| | - Melvin E Andersen
- Center for Human Health Assessment, The Hamner Institutes for Health Sciences, 6 Davis Drive, P.O. Box 12137, Research Triangle Park, NC 27709, United States
| | - Harvey J Clewell
- Center for Human Health Assessment, The Hamner Institutes for Health Sciences, 6 Davis Drive, P.O. Box 12137, Research Triangle Park, NC 27709, United States
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Morford LL, Bowman CJ, Blanset DL, Bøgh IB, Chellman GJ, Halpern WG, Weinbauer GF, Coogan TP. Preclinical safety evaluations supporting pediatric drug development with biopharmaceuticals: strategy, challenges, current practices. ACTA ACUST UNITED AC 2011; 92:359-80. [PMID: 21770023 DOI: 10.1002/bdrb.20305] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 04/11/2011] [Indexed: 11/08/2022]
Abstract
Evaluation of pharmaceutical agents in children is now conducted earlier in the drug development process. An important consideration for this pediatric use is how to assess and support its safety. This article is a collaborative effort of industry toxicologists to review strategies, challenges, and current practice regarding preclinical safety evaluations supporting pediatric drug development with biopharmaceuticals. Biopharmaceuticals include a diverse group of molecular, cell-based or gene therapeutics derived from biological sources or complex biotechnological processes. The principles of preclinical support of pediatric drug development for biopharmaceuticals are similar to those for small molecule pharmaceuticals and in general follow the same regulatory guidances outlined by the Food and Drug Administration and European Medicines Agency. However, many biopharmaceuticals are also inherently different, with limited species specificity or immunogenic potential which may impact the approach taken. This article discusses several key areas to aid in the support of pediatric clinical use, study design considerations for juvenile toxicity studies when they are needed, and current practices to support pediatric drug development based on surveys specifically targeting biopharmaceutical development.
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Kern CH, Smith DR. Preweaning Mn exposure leads to prolonged astrocyte activation and lasting effects on the dopaminergic system in adult male rats. Synapse 2010; 65:532-44. [PMID: 20963817 DOI: 10.1002/syn.20873] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 09/28/2010] [Indexed: 01/18/2023]
Abstract
Little is known about the effects of manganese (Mn) exposure over neurodevelopment and whether these early insults result in effects lasting into adulthood. To determine if early Mn exposure produces lasting neurobehavioral and neurochemical effects, we treated neonate rats with oral Mn (0, 25, or 50 mg Mn/kg/d over PND 1-21) and evaluated (1) behavioral performance in the open arena in the absence (PND 97) and presence (PND 98) of a d-amphetamine challenge, (2) brain dopamine D1 and D2-like receptors and dopamine transporter densities in the prefrontal cortex, striatum, and nucleus accumbens (PND 107), and (3) astrocyte marker glial fibrillary acidic protein (GFAP) levels in these same brain regions (PND 24 and 107). We found that preweaning Mn exposure did not alter locomotor activity or behavior disinhibition in adult rats, though Mn-exposed animals did exhibit an enhanced locomotor response to d-amphetamine challenge. Preweaning Mn exposure led to increased D1 and D2 receptor levels in the nucleus accumbens and prefrontal cortex, respectively, compared with controls. We also found increased GFAP expression in the prefrontal cortex in Mn-exposed PND 24 weanlings, and increased GFAP levels in prefrontal cortex, medial striatum and nucleus accumbens of adult (PND 107) rats exposed to preweaning Mn, indicating an effect of Mn exposure on astrogliosis that persisted and/or progressed to other brain regions in adult animals. These data show that preweaning Mn exposure leads to lasting molecular and functional impacts in multiple brain regions of adult animals, long after brain Mn levels returned to normal.
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Affiliation(s)
- Cynthia H Kern
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California 95064, USA
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Kern CH, Stanwood GD, Smith DR. Preweaning manganese exposure causes hyperactivity, disinhibition, and spatial learning and memory deficits associated with altered dopamine receptor and transporter levels. Synapse 2010; 64:363-78. [PMID: 20029834 DOI: 10.1002/syn.20736] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Epidemiological studies in children have reported associations between elevated dietary manganese (Mn) exposure and neurobehavioral and neurocognitive deficits. To better understand the relationship between early Mn exposure and neurobehavioral deficits, we treated neonate rats with oral Mn doses of 0, 25, or 50 mg Mn/kg/day over postnatal day (PND) 1-21, and evaluated behavioral performance using open arena (PND 23), elevated plus maze (PND 23), and 8-arm radial maze (PND 33-46) paradigms. Brain dopamine D1 and D2-like receptors, and dopamine transporter (DAT) densities were determined on PND 24, and blood and brain Mn levels were measured to coincide with behavioral testing (PND 24, PND 36). Preweaning Mn exposure caused hyperactivity and behavioral disinhibition in the open arena, but no altered behavior in the elevated plus maze. Manganese-exposed males committed significantly more reference and marginally more working errors in the radial arm maze compared to controls. Fewer Mn exposed males achieved the radial maze learning criterion, and they required more session days to reach it compared to controls. Manganese-exposed animals also exhibited a greater frequency of stereotypic response strategy in searching for the baited arms in the maze. These behavioral and learning deficits were associated with altered expression of the dopamine D1 and D2 receptors and the DAT in prefrontal cortex, nucleus accumbens, and dorsal striatum. These data corroborate epidemiological studies in children, and suggest that exposure to Mn during neurodevelopment significantly alters dopaminergic synaptic environments in brain nuclei that mediate control of executive function behaviors, such as reactivity and cognitive flexibility.
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Affiliation(s)
- Cynthia H Kern
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California 95064, USA.
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Elbarbry F, Alcorn J. Ontogeny of glutathione and glutathione-related antioxidant enzymes in rat liver. Res Vet Sci 2009; 87:242-4. [DOI: 10.1016/j.rvsc.2009.03.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 02/11/2009] [Accepted: 03/03/2009] [Indexed: 01/21/2023]
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Yoon M, Nong A, Clewell HJ, Taylor MD, Dorman DC, Andersen ME. Lactational Transfer of Manganese in Rats: Predicting Manganese Tissue Concentration in the Dam and Pups from Inhalation Exposure with a Pharmacokinetic Model. Toxicol Sci 2009; 112:23-43. [DOI: 10.1093/toxsci/kfp197] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Expert Report: Making Decisions about the Risks of Chemicals in Foods with Limited Scientific Information. Compr Rev Food Sci Food Saf 2009; 8:269-303. [DOI: 10.1111/j.1541-4337.2009.00081.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Pharmacokinetic modeling of perfluorooctanoic acid during gestation and lactation in the mouse. Reprod Toxicol 2009; 27:373-386. [PMID: 19429408 DOI: 10.1016/j.reprotox.2009.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 02/03/2009] [Accepted: 02/19/2009] [Indexed: 11/22/2022]
Abstract
Perfluorooctanoic acid (PFOA) is a processing aid for the polymerization of commercially valuable fluoropolymers. Its widespread environmental distribution, presence in human blood, and adverse effects in animal toxicity studies have triggered attention to its potential adverse effects to humans. PFOA is not metabolized and exhibits dramatically different serum/plasma half-lives across species. Estimated half-lives for humans, monkeys, mice, and female rats are 3-5 years, 20-30 days, 12-20 days, and 2-4h, respectively. Developmental toxicity is one of the most sensitive adverse effects associated with PFOA exposure in rodents, but its interpretation for risk assessment is currently hampered by the lack of understanding of the inter-species pharmacokinetics of PFOA. To address this uncertainty, a biologically supported dynamic model was developed whereby a two-compartment system linked via placental blood flow described gestation and milk production linked a lactating dam to a growing pup litter compartment. Postnatal serum levels of PFOA for 129S1/SvImJ mice at doses of 1mg/kg or less were reasonably simulated while prenatal and postnatal measurements for CD-1 mice at doses of 1mg/kg or greater were simulated via the addition of a biologically based saturable renal resorption description. Our results suggest that at low doses a linear model may suffice for describing the pharmacokinetics of PFOA while a more complex model may be needed at higher doses. Although mice may appear more sensitive based on administered dose of PFOA, the internal dose metrics estimated in this analysis indicate that they may be equal or less sensitive than rats.
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