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Golshan M, Alavi SMH, Hatef A, Kazori N, Socha M, Milla S, Sokołowska-Mikołajczyk M, Unniappan S, Butts IAE, Linhart O. Impact of absolute food deprivation on the reproductive system in male goldfish exposed to sex steroids. J Comp Physiol B 2024; 194:411-426. [PMID: 38880793 DOI: 10.1007/s00360-024-01570-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/18/2024] [Accepted: 06/05/2024] [Indexed: 06/18/2024]
Abstract
There is a link between metabolism and reproduction as metabolic hormones affect hypothalamus-pituitary-testis (HPT) hormonal functions and vice versa. The aim of the present study was to investigate the effects of negative energy balance on the reproductive system in male goldfish exposed to testosterone (T) and 17β-estradiol (E2). Following 7 days of food deprivation (FD), ANOVA models showed significant FD × sex steroid interactions on sperm quality and circulating sex steroid levels. When FD effects were investigated, 11-ketotestosterone (11-KT) level and sperm motility and velocity decreased in food-deprived goldfish in the control group. In E2-exposed goldfish, FD decreased sperm production in addition to sperm motility and velocity that coincided with an elevation of circulating E2 level. However, FD did not significantly impact sex steroids and sperm quality in T-exposed goldfish. ANOVA models showed non-significant FD × sex steroid interactions for HSI, GSI, circulating luteinizing hormone (Lh) level, and metabolic (preproghrelin, goat and nucb2) and reproductive (kiss1, gpr54 and gnrh3) mRNAs. Furthermore, results showed that FD decreased HSI, and increased Lh levels and testicular preproghrelin and goat mRNAs, while sex steroids increased mid-brain nucb2, kiss1 and gpr54 mRNAs. Together, our results suggest that FD-induced inhibition of androgenesis resulted in diminished sperm quality associated with activation of the testicular ghrelinergic system, and negative feedback of 11-KT increased Lh level. The FD-induced testicular metabolic and hormonal system was impacted in goldfish exposed to sex steroids. However, the negative effects of FD on sperm quality were accelerated in E2-exposed goldfish due to estrogenic activity. This study provides novel information to better understand metabolic-associated reproductive disorders in fish.
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Affiliation(s)
- Mahdi Golshan
- Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Tehran, Iran
| | - Sayyed Mohammad Hadi Alavi
- South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in České Budějovice, Vodňany, Czech Republic.
- School of Biology, College of Science, University of Tehran, Tehran, Iran.
| | - Azadeh Hatef
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B4, Canada
- Toxicology Centre, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B3, Canada
| | - Negar Kazori
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Magdalena Socha
- Faculty of Animal Science, University of Agriculture in Kraków, Kraków, Poland
| | - Sylvain Milla
- Research Unit Animal and Functionalities of Animal Products, INRA, University of Lorraine, Vandoeuvre-lès-Nancy, France
| | | | - Suraj Unniappan
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Ian A E Butts
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Otomar Linhart
- South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in České Budějovice, Vodňany, Czech Republic
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Lewis RW, Andrus AK, Arroyo J, Brescia S, Botham PA, Corvaro M, Daston GP, Hofmann T, Rodriguez C, Sewell F, van Ravenzwaay B, Wiench K, Marty S. Considerations for the development of guidance on dose level selection for developmental and reproductive toxicity studies. Regul Toxicol Pharmacol 2024; 148:105585. [PMID: 38403008 DOI: 10.1016/j.yrtph.2024.105585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/06/2024] [Accepted: 02/18/2024] [Indexed: 02/27/2024]
Abstract
In 2022, the European Chemicals Agency issued advice on the selection of high dose levels for developmental and reproductive toxicity (DART) studies indicating that the highest dose tested should aim to induce clear evidence of reproductive toxicity without excessive toxicity and severe suffering in parental animals. In addition, a recent publication advocated that a 10% decrease in body weight gain should be replaced with a 10% decrease in bodyweight as a criterion for dose adequacy. Experts from the European Centre for Ecotoxicology and Toxicology of Chemicals evaluated these recent developments and their potential impact on study outcomes and interpretation and identified that the advice was not aligned with OECD test guidelines or with humane endpoints guidance. Furthermore, data analysis from DART studies indicated that a 10% decrease in maternal body weight during gestation equates to a 25% decrease in body weight gain, which differs from the consensus of experts at a 2010 ILSI/HESI workshop. Dose selection should be based on a biological approach that considers a range of other factors. Excessive dose levels that cause frank toxicity and overwhelm homeostasis should be avoided as they can give rise to effects that are not relevant to human health assessments.
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Affiliation(s)
- R W Lewis
- Regulatory Science Associates, Inverkip, Glasgow, Scotland, UK
| | - A K Andrus
- The Dow Chemical Company, Midland, MI, USA
| | | | - S Brescia
- Health & Safety Executive, Chemicals Regulation Division (CRD), Bootle, UK
| | | | - M Corvaro
- Corteva Agriscience Italia S.r.l., Rome, Italy
| | | | | | | | - F Sewell
- National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), London, UK.
| | | | | | - S Marty
- The Dow Chemical Company, Midland, MI, USA
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Lee MJ, Cha HG, Park KY, Kim YS, Ahn B. N-methylformamide induces multiple organ toxicity in Fischer 344 rats. Toxicol Res 2023; 39:263-274. [PMID: 37008692 PMCID: PMC10050240 DOI: 10.1007/s43188-022-00165-x] [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: 09/13/2022] [Revised: 12/01/2022] [Accepted: 12/15/2022] [Indexed: 01/19/2023] Open
Abstract
N-Methylformamide (NMF) is a widely used chemical (CAS No.: 123-39-7) in several industries and its usage is continuously increasing. However, studies for NMF have been focused on hepatotoxicity from now. Its toxicity profile has not yet been established owing to limited toxicity data. Therefore, we evaluated systemic toxicity via NMF inhalation. We exposed 0, 30, 100, and 300 ppm NMF to Fischer 344 rats for 6 h/day, 5 days a week for 2 weeks. Clinical signs, body weights, food consumption, hematologic parameters, serum chemistry measurements, organ weights, necropsy, and histopathology were performed. Two females exposed to 300 ppm NMF died during exposure period. Decrease of food consumption and body weight in both sexes exposed to 300 ppm in females exposed to 100 ppm were noted during exposure period. Increased RBC and HGB were noted in females exposed to 300 ppm. A decrease in the levels of ALP and K and increase in the levels of TCHO and Na were observed in both sexes exposed to 300 and 100 ppm. Increased levels of ALT, AST, BUN and decreased levels of TP, ALB, Ca were observed in females exposed to 300 and 100 ppm. The relative liver weight was elevated in both sexes exposed to 300 and 100 ppm NMF. Hypertrophy in the liver and submandibular glands and nasal cavity injuries were noted in both sexes exposed to 300 and 100 ppm NMF. Tubular basophilia of the kidneys were noted in females exposed to 300 ppm NMF. We revealed that NMF affect several organs including the kidneys not only the liver and NMF-related toxicity is predominant in female rats. These results could contribute to the development of NMF toxicity profile and may help in developing strategies for the control of occupational environmental hazards related to NMF.
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Affiliation(s)
- Mi Ju Lee
- Inhalation Toxicity Research Center, Chemicals Toxicity Research Bureau, Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency, 30, Expo-ro 339beon-gil, Yuseong-gu, Daejeon, 34122 Republic of Korea
- Department of Veterinary Pathology, College of Veterinary Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644 Republic of Korea
| | - Hyo-Geun Cha
- Inhalation Toxicity Research Center, Chemicals Toxicity Research Bureau, Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency, 30, Expo-ro 339beon-gil, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Ka Young Park
- Inhalation Toxicity Research Center, Chemicals Toxicity Research Bureau, Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency, 30, Expo-ro 339beon-gil, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Yong-Soon Kim
- Inhalation Toxicity Research Center, Chemicals Toxicity Research Bureau, Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency, 30, Expo-ro 339beon-gil, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Byeongwoo Ahn
- Department of Veterinary Pathology, College of Veterinary Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644 Republic of Korea
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Barlow SM, Terry C, Gehen S, Corvaro M. Reproductive and developmental evaluations of triclopyr acid, triclopyr butoxyethyl ester and triclopyr triethylamine salt in the rat. Food Chem Toxicol 2022; 161:112806. [PMID: 34995710 DOI: 10.1016/j.fct.2021.112806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/29/2021] [Accepted: 12/31/2021] [Indexed: 11/30/2022]
Abstract
Reproductive and developmental toxicity studies have been conducted in rat and rabbit on triclopyr acid and its active-ingredient variants, triclopyr butoxyethyl ester (T-BEE) and triclopyr triethylamine salt (T-TEA). In this paper the results of a rat two-generation study on triclopyr acid are presented, together with a review of all the reproductive and developmental toxicity data available from the rat studies. In the rat two-generation study, triclopyr acid was administered in the diet, giving doses of 0, 5, 25 or 250 mg/kg bw per day. Parental toxicity, especially maternal toxicity, occurred at 250 mg/kg bw per day with reduced body weight and feed intake, organ weight changes, and kidney toxicity. Slight kidney toxicity was also evident at 25 mg/kg bw per day. Developmental toxicity, in the form of reduced postnatal survival in the F1 and F2 generations and reductions in pre-weaning offspring body weight in both generations, was seen only at a dose causing significant parental toxicity. There were no effects on any other reproductive or developmental parameters at any dose. It is concluded that the developmental toxicity, seen only at the highest dose, was most likely attributable to maternal toxicity. The no-observed-adverse-effect levels were 5 mg/kg bw per day for parental toxicity and 25 mg/kg bw per day for developmental toxicity. From the multigeneration and developmental toxicity studies on triclopyr and its variants, it can also be concluded that triclopyr is not specifically toxic to reproduction and is not selectively toxic to the embryo, fetus or neonate in the rat.
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Affiliation(s)
| | - Claire Terry
- Dow AgroSciences LCC, Member of Corteva Agriscience Group of Companies, 9330 Zionsville Rd, Indianapolis, IN, 46268, USA
| | - Sean Gehen
- Dow AgroSciences LCC, Member of Corteva Agriscience Group of Companies, 9330 Zionsville Rd, Indianapolis, IN, 46268, USA
| | - Marco Corvaro
- Dow Agrosciences Italia S.r.l, Member of Corteva Agriscience Group of Companies, Via dei Comizi Agrari 10, 26100, Cremona, CR, Italy.
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Multigenerational reproductive assessment of 4-methylimidazole administered in the diet to Hsd:Sprague Dawley SD rats. Reprod Toxicol 2020; 98:13-28. [DOI: 10.1016/j.reprotox.2020.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 02/11/2020] [Accepted: 03/11/2020] [Indexed: 02/07/2023]
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Kisspeptin-52 partially rescues the activity of the hypothalamus-pituitary-gonadal axis in underweight male rats dosed with an anti-obesity compound. Toxicol Appl Pharmacol 2020; 404:115152. [PMID: 32726590 DOI: 10.1016/j.taap.2020.115152] [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: 05/20/2020] [Revised: 07/09/2020] [Accepted: 07/16/2020] [Indexed: 11/21/2022]
Abstract
Energy metabolism and reproduction are closely linked and reciprocally regulated. The detrimental effect of underweight on reproduction complicates the safety evaluation of anti-obesity drugs, making it challenging to distinguish pathological changes mediated through the intended drug-induced weight loss from direct drug effects on reproductive organs. Four-weeks dosing of normal weight Sprague Dawley rats with a glucagon-like peptide 1 (GLP-1)/glucagon receptor co-agonist induced a robust weight loss, accompanied by histological findings in prostate, seminal vesicles, mammary glands, uterus/cervix and vagina. Characterization of the hypothalamus-pituitary-gonadal (HPG) axis in male rats revealed reduced hypothalamic Kiss1 mRNA levels and decreased serum luteinizing hormone (LH) and testosterone concentrations following co-agonist dosing. These alterations resemble hypogonadotropic hypogonadism typically seen in adverse energy deprived conditions, like chronic food restriction. Concomitant daily administration of kisspeptin-52 from day 21 to the end of the four-week co-agonist dosing period evoked LH and testosterone responses without normalizing histological findings. This incomplete rescue by kisspeptin-52 may be due to the rather short kisspeptin-52 treatment period combined with a desensitization observed on testosterone responses. Concomitant leptin treatment from day 21 did not reverse co-agonist induced changes in HPG axis activity. Furthermore, a single co-agonist injection in male rats slightly elevated LH levels but left testosterone unperturbed, thereby excluding a direct acute inhibitory effect on the HPG axis. Our data suggest that the reproductive phenotype after repeated co-agonist administration was driven by the intended weight loss, however, we cannot exclude a direct organ related effect in chronically treated rats.
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Macartney EL, Crean AJ, Nakagawa S, Bonduriansky R. Effects of nutrient limitation on sperm and seminal fluid: a systematic review and meta-analysis. Biol Rev Camb Philos Soc 2019; 94:1722-1739. [PMID: 31215758 DOI: 10.1111/brv.12524] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 05/01/2019] [Accepted: 05/03/2019] [Indexed: 01/05/2023]
Abstract
Theory predicts that costly sexual traits should be reduced when individuals are in poor condition (i.e. traits should exhibit condition-dependent expression). It is therefore widely expected that male ejaculate traits, such as sperm and seminal fluid, will exhibit reduced quantity and quality when dietary nutrients are limited. However, reported patterns of ejaculate condition dependence are highly variable, and there has been no comprehensive synthesis of underlying sources of such variation in condition-dependent responses. In particular, it remains unclear whether all ejaculate traits are equally sensitive to nutrient intake, and whether such traits are particularly sensitive to certain dietary nutrients, respond more strongly to nutrients during specific life stages, or respond more strongly in some taxonomic groups. We systematically reviewed these potential sources of variation through a meta-analysis across 50 species of arthropods and vertebrates (from 71 papers and 348 effect sizes). We found that overall, ejaculate traits are moderately reduced when dietary nutrients are limited, but we also detected substantial variation in responses. Seminal fluid quantity was strongly and consistently condition dependent, while sperm quantity was moderately condition dependent. By contrast, aspects of sperm quality (particularly sperm viability and morphology) were less consistently reduced under nutrient limitation. Ejaculate traits tended to respond in a condition-dependent manner to a wide range of dietary manipulations, especially to caloric and protein restriction. Finally, while all major taxa for which sufficient data exist (i.e. arthropods, mammals, fish) showed condition dependence of ejaculate traits, we detected some taxonomic differences in the life stage that is most sensitive to nutrient limitation, and in the degree of condition dependence of specific ejaculate traits. Together, these biologically relevant factors accounted for nearly 20% of the total variance in ejaculate responses to nutrient limitation. Interestingly, body size showed considerably stronger condition-dependent responses compared to ejaculate traits, suggesting that ejaculate trait expression may be strongly canalised to protect important reproductive functions, or that the cost of producing an ejaculate is relatively low. Taken together, our findings show that condition-dependence of ejaculate traits is taxonomically widespread, but there are also many interesting, biologically relevant sources of variation that require further investigation. In particular, further research is needed to understand the differences in selective pressures that result in differential patterns of ejaculate condition dependence across taxa and ejaculate traits.
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Affiliation(s)
- Erin L Macartney
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Angela J Crean
- Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Shinichi Nakagawa
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Russell Bonduriansky
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, UNSW Australia, Sydney, New South Wales, Australia
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Morgan CP, Chan JC, Bale TL. Driving the Next Generation: Paternal Lifetime Experiences Transmitted via Extracellular Vesicles and Their Small RNA Cargo. Biol Psychiatry 2019; 85:164-171. [PMID: 30580777 PMCID: PMC6309802 DOI: 10.1016/j.biopsych.2018.09.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/29/2018] [Accepted: 09/17/2018] [Indexed: 10/28/2022]
Abstract
Epidemiological studies provide strong evidence for the impact of diverse paternal life experiences on offspring neurodevelopmental disease risk. While these associations are well established, the molecular mechanisms underlying these intergenerational transmissions remain elusive, though recent studies focusing on the influence of paternal experience before conception have implicated germ cell epigenetic programming. Any model accounting for the germline transfer of nongenetic information from sire to offspring must include certain components, such as 1) a vector to carry any signal from the paternal compartment to the maternal reproductive tract and future embryo; 2) a molecular signal, encoded by a paternal experience, to carry this memory and enact downstream responses; and 3) a target cell or tissue to receive the signal and convert it into an effect on embryonic development. We explore the current understanding of the potential processes and candidate factors that may serve as these components. We specifically discuss the growing appreciation for the importance of extracellular vesicles in these processes, beginning with their known role in delivering potential signals, including small RNAs, to sperm, the prototypical vector, during their posttesticular maturation. Finally, we explore the possibility that paternal extracellular vesicles could themselves serve as vectors, delivering signals not only to gametes or the zygote but also to tissues of the maternal reproductive tract to influence fetal development.
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Affiliation(s)
- Christopher P Morgan
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jennifer C Chan
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Tracy L Bale
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland.
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Nakamura N, Vijay V, Desai VG, Hansen DK, Han T, Chang CW, Chen YC, Harrouk W, McIntyre B, Foster PM, Fuscoe JC, Inselman AL. Transcript profiling in the testes and prostates of postnatal day 30 Sprague-Dawley rats exposed prenatally and lactationally to 2-hydroxy-4-methoxybenzophenone. Reprod Toxicol 2018; 82:111-123. [PMID: 30316929 PMCID: PMC6434700 DOI: 10.1016/j.reprotox.2018.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 09/19/2018] [Accepted: 10/03/2018] [Indexed: 01/13/2023]
Abstract
2-hydroxy-4-methoxybenzophenone (HMB) is an ultraviolet light-absorbing compound that is used in sunscreens, cosmetics and plastics. HMB has been reported to have weak estrogenic activity by in vivo and in vitro studies, making it a chemical with potential reproductive concern. To explore if prenatal and lactational HMB exposure alters gene expression profiles of the developing reproductive organs, we performed microarray analysis using the prostate and testis of postnatal day (PND) 30 male Sprague-Dawley rats offspring exposed to 0, 3000, or 30,000 ppm of HMB from gestational day 6 through PND 21. Gene expression profiles of the prostate and testis were differentially affected by HMB dose with significant alterations observed at the 30,000 ppm HMB group. Tissue-specific gene expression was also identified. These genes, whose expression was altered by HMB exposure, may be considered as candidate biomarker(s) for testicular or prostatic toxicity; however, further studies are necessary to explore this potential.
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Affiliation(s)
- Noriko Nakamura
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States.
| | - Vikrant Vijay
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Varsha G Desai
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Deborah K Hansen
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Tao Han
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Ching-Wei Chang
- Division of Bioinformatics and Biostatistics, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Yu-Chuan Chen
- Division of Bioinformatics and Biostatistics, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Wafa Harrouk
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, United States
| | - Barry McIntyre
- National Toxicology Program, Research Triangle Park, NC 27709, United States
| | - Paul M Foster
- National Toxicology Program, Research Triangle Park, NC 27709, United States
| | - James C Fuscoe
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Amy L Inselman
- Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
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Catlin NR, Willson CJ, Creasy DM, Rao DB, Kissling GE, McIntyre BS, Wyde M. Differentiating between Testicular Toxicity and Sexual Immaturity in Ortho-phthalaldehyde Inhalation Toxicity Studies in Rats and Mice. Toxicol Pathol 2018; 46:753-763. [PMID: 30259793 DOI: 10.1177/0192623318801790] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Early deaths of young or juvenile animals (before sexual maturation is achieved) in routine regulatory safety studies present pathologists and toxicologists with the challenge of interpreting findings in the male reproductive tract. Additionally, the advent of toxicity testing regulations has resulted in a growing need for the use of juvenile animals in toxicology studies. Here, we present the reproductive toxicity findings from a 13-week inhalation toxicity study with ortho-phthalaldehyde (OPA) in male rats and mice as a case example for working through this challenging task. In this study with OPA, survival was significantly reduced in the two highest exposure concentrations of OPA tested. Early deaths and histopathological lesions in the testes and epididymides were generally also limited to these two highest exposure groups. Therefore, there was concern that peripubertal morphological features could be a confounding factor for the histopathological evaluation of exposure-related testicular and epididymal findings. Although it can be difficult to differentiate exposure-related effects from the normal morphological features defining peripubertal changes in the testes and epididymides in animals that die early in a toxicity study, the use of age-matched controls in this case study with OPA provided a reference and aided in the differentiation of these effects.
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Affiliation(s)
- Natasha R Catlin
- 1 National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.,2 Current address: Pfizer Inc., Groton, Connecticut, USA
| | | | | | - Deepa B Rao
- 3 Integrated Laboratory Systems, Morrisville, North Carolina, USA.,5 Current address: Food and Drug Administration, Silver Spring, Maryland, USA
| | - Grace E Kissling
- 1 National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Barry S McIntyre
- 1 National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Michael Wyde
- 1 National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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Marty MS, Borgert C, Coady K, Green R, Levine SL, Mihaich E, Ortego L, Wheeler JR, Yi KD, Zorrilla LM. Distinguishing between endocrine disruption and non-specific effects on endocrine systems. Regul Toxicol Pharmacol 2018; 99:142-158. [PMID: 30217484 DOI: 10.1016/j.yrtph.2018.09.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/04/2018] [Indexed: 10/28/2022]
Abstract
The endocrine system is responsible for growth, development, maintaining homeostasis and for the control of many physiological processes. Due to the integral nature of its signaling pathways, it can be difficult to distinguish endocrine-mediated adverse effects from transient fluctuations, adaptive/compensatory responses, or adverse effects on the endocrine system that are caused by mechanisms outside the endocrine system. This is particularly true in toxicological studies that require generation of effects through the use of Maximum Tolerated Doses (or Concentrations). Endocrine-mediated adverse effects are those that occur as a consequence of the interaction of a chemical with a specific molecular component of the endocrine system, for example, a hormone receptor. Non-endocrine-mediated adverse effects on the endocrine system are those that occur by other mechanisms. For example, systemic toxicity, which perturbs homeostasis and affects the general well-being of an organism, can affect endocrine signaling. Some organs/tissues can be affected by both endocrine and non-endocrine signals, which must be distinguished. This paper examines in vitro and in vivo endocrine endpoints that can be altered by non-endocrine processes. It recommends an evaluation of these issues in the assessment of effects for the determination of endocrine disrupting properties of chemicals. This underscores the importance of using a formal weight of evidence (WoE) process to evaluate potential endocrine activity.
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Affiliation(s)
- M Sue Marty
- The Dow Chemical Company, Toxicology & Environmental Research and Consulting, 1803 Building, Midland, MI, 48674, USA.
| | - Chris Borgert
- Applied Pharmacology and Toxicology, Inc., C.E.H.T. Dept. Physiological Sciences, University of FL College of Veterinary Medicine, 2250 NW 24th Avenue, Gainesville, FL, 32605, USA.
| | - Katie Coady
- The Dow Chemical Company, Toxicology & Environmental Research and Consulting, 1803 Building, Midland, MI, 48674, USA.
| | - Richard Green
- Dow AgroSciences, 3b Park Square, Milton Park, Abingdon, Oxfordshire, OX14 4RN, United Kingdom.
| | - Steven L Levine
- Monsanto Company, Global Regulatory Science, 700 Chesterfield Parkway W, Chesterfield, MO, 63017, USA.
| | - Ellen Mihaich
- Environmental and Regulatory Resources, LLC, 6807 Lipscomb Drive, Durham, NC, 27712, USA.
| | - Lisa Ortego
- Bayer CropScience, 2 TW Alexander Dr, Research Triangle Park, NC, 27709, USA.
| | - James R Wheeler
- Dow AgroSciences, 3b Park Square, Milton Park, Abingdon, Oxfordshire, OX14 4RN, United Kingdom.
| | - Kun Don Yi
- Syngenta Crop Protection, LLC, 410 S Wing Rd, Greensboro, NC, 27409, USA.
| | - Leah M Zorrilla
- Bayer CropScience, 2 TW Alexander Dr, Research Triangle Park, NC, 27709, USA.
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Ak Sonat F, Alcay S, Toker MB, Peker S, Ustuner B. The effects of dietary restriction and administration of β-glucan from Euglena gracilis on the sperm characteristics and reproductive organs of rats. Andrologia 2018; 50:e13088. [PMID: 29987855 DOI: 10.1111/and.13088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 12/13/2022] Open
Abstract
The aim of this study was to demonstrate the possible individual and/or synergistic effects of β-glucan and dietary restrictions on the reproductive parameters of rats. For this purpose, forty male Sprague-Dawley rats were randomly divided into four equal groups (n = 10 per group). The first group was the control, the second group was kept under dietary restriction (DR), the third group was kept under a dietary restriction and given β-glucan (DR + βG) and the fourth group was supplemented only with β-glucan (βG; 20 mg/kg) intragastrically for 14 days. Motility, vitality and morphology of spermatozoa, reproductive organ weights (testis, vesicula seminalis and epididymis) and seminiferous tubule diameters were evaluated in experimental rats. β-glucan had excellent effects on motility, live spermatozoa rate and the acrosome integrity when compared to the control group (p < 0.05). We also observed that β-glucan administration to rats having dietary restriction could improve sperm motility and acrosome integrity (p < 0.05). While the β-glucan improved seminiferous tubule diameter (p < 0.05), weights of the reproductive organs did not change positively as a result. This study demonstrated that β-glucan treatment significantly improved some spermatological characteristics in rats. Therefore, treatment with β-glucan could be used for its positive effects on motility, spermatozoa vitality rate and acrosome integrity for infertile men.
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Affiliation(s)
- Fusun Ak Sonat
- Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Görükle/Bursa, Turkey
| | - Selim Alcay
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Uludag University, Gorukle/Bursa, Turkey
| | - Mehmed Berk Toker
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Uludag University, Gorukle/Bursa, Turkey
| | - Sabire Peker
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Uludag University, Gorukle/Bursa, Turkey
| | - Burcu Ustuner
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Uludag University, Gorukle/Bursa, Turkey
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Picut CA, Remick AK. Impact of Age on the Male Reproductive System from the Pathologist’s Perspective. Toxicol Pathol 2016; 45:195-205. [DOI: 10.1177/0192623316672744] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Age, and in particular young age, can significantly impact the response to toxicants in animals and can greatly influence the interpretation of tissue changes by the toxicologic pathologist. Although this applies to multiple organ systems, the current review focuses on the male reproductive system. When performing microscopic evaluation of male reproductive organs, the toxicologic pathologist must be aware of the dynamic changes in histomorphology, predominantly driven by timed hormonal alterations, at various life stages. Specific challenges pathologists face are understanding the appearance of male reproductive tissues throughout the neonatal, infantile, and juvenile developmental periods, recognizing when normal looks abnormal during tissue development, defining sexual maturity, and working with high interanimal variability in maturation rate and histologic appearance in developing large laboratory animals, such as nonhuman primates, dogs, and pigs. This review describes postnatal development of the male reproductive system in the rat, demonstrates how assessing toxicity during a defined window of postnatal development in the rat may improve definition of toxicant timing and targets, and discusses challenges associated with the interpretation of toxicity in immature large animal species. The emphasis is on key age-related characteristics that influence the interpretation of tissue changes by the toxicologic pathologist.
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Affiliation(s)
- Catherine A. Picut
- Charles River Laboratories, Pathology Associates, Durham, North Carolina, USA
| | - Amera K. Remick
- Charles River Laboratories, Pathology Associates, Durham, North Carolina, USA
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Bozkaya F, Atli MO, Guzeloglu A, Kayis SA, Yildirim ME, Kurar E, Yilmaz R, Aydilek N. Effects of long-term heat stress and dietary restriction on the expression of genes of steroidogenic pathway and small heat-shock proteins in rat testicular tissue. Andrologia 2016; 49. [DOI: 10.1111/and.12668] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2016] [Indexed: 01/14/2023] Open
Affiliation(s)
- F. Bozkaya
- Department of Genetics; Faculty of Veterinary Medicine; Harran University; Sanliurfa Turkey
| | - M. O. Atli
- Department of ObGyn; Faculty of Veterinary Medicine; Dicle University; Diyarbakir Turkey
| | - A. Guzeloglu
- Department of Genetics; Faculty of Veterinary Medicine; Selcuk University; Konya Turkey
| | - S. A. Kayis
- Department of Biostatistics; Faculty of Medicine; Karabuk University; Karabuk Turkey
| | - M. E. Yildirim
- Department of Urology; Faculty of Medicine; Turgut Ozal University; Ankara Turkey
| | - E. Kurar
- Department of Medical Biology; Faculty of Medicine; Necmettin Erbakan University; Konya Turkey
| | - R. Yilmaz
- Department of Pathology; Faculty of Veterinary Medicine; Harran University; Sanliurfa Turkey
| | - N. Aydilek
- Department of Physiology; Faculty of Veterinary Medicine; Dicle University; Diyarbakir Turkey
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15
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Gabrielsen JS, Tanrikut C. Chronic exposures and male fertility: the impacts of environment, diet, and drug use on spermatogenesis. Andrology 2016; 4:648-61. [DOI: 10.1111/andr.12198] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 03/07/2016] [Accepted: 03/10/2016] [Indexed: 01/02/2023]
Affiliation(s)
- J. S. Gabrielsen
- Department of Urology; Massachusetts General Hospital; Boston MA USA
| | - C. Tanrikut
- Department of Urology; Massachusetts General Hospital; Boston MA USA
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16
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Paternal calorie restriction prior to conception alters anxiety-like behavior of the adult rat progeny. Psychoneuroendocrinology 2016; 64:1-11. [PMID: 26571216 DOI: 10.1016/j.psyneuen.2015.10.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 10/26/2015] [Indexed: 11/22/2022]
Abstract
The maternal environment influences a broad range of phenotypic outcomes for offspring, with anxiety-like behavior being particularly susceptible to maternal environmental perturbations. Much less is known regarding paternal environmental influences. To investigate this, adult male rats were exposed to 25% calorie restriction (CR) or glucocorticoid elevation (CORT; 200 μg/ml of corticosterone in drinking water) for ∼ 6 weeks prior to breeding. Elevated plus maze (EPM), open field (OF), predator odor (cat urine), and acoustic startle/pre-pulse inhibition (AS/PPI) were characterised in the adult male offspring. Plasma concentrations of corticotrophin-releasing hormone (CRF), adrenocorticotropin hormone (ACTH), and serum leptin were characterised in both sires and offspring. Maternal care received by litters was additionally observed. Expectedly, CR and CORT treatment attenuated weight gain, whilst only CR induced anxiolytic behavior in the EPM. The adult offspring sired by CR males also demonstrated a reduction in weight gain, food intake and serum leptin levels when compared to controls. Moreover, CR offspring demonstrated an anxiolytic-like profile in the EPM and OF, enhanced habituation to the AS pulse, reduced PPI, but no alteration to predator odor induced defensiveness compared to control. CORT offspring failed to demonstrate any behavioral differences from controls, however, exhibited a trend towards reduced ACTH and leptin concentration. Collectively, the results indicate that a reduction in calories in males prior to conception can affect the behavior of adult offspring. The phenotypic transmission of CR experiences from fathers to the progeny could potentially be mediated epigenetically. The role of glucocorticoid elevation and maternal care are also discussed.
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Crincoli CM, Brathwaite WA, Casterton PL, Rihner MO, Nikiforov AI, Sloter ED, Harris SB. A dietary two-generation reproductive toxicity study of (2R,4R)-monatin salt in Crl:CD(SD) rats. Food Chem Toxicol 2015; 91:167-80. [PMID: 26514697 DOI: 10.1016/j.fct.2015.10.015] [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: 06/17/2015] [Revised: 10/14/2015] [Accepted: 10/23/2015] [Indexed: 10/22/2022]
Abstract
(2R,4R)-Monatin salt [sodium/potassium 2R,4R-2-amino-4-carboxy-4-hydroxy-5-(3-indolyl) pentanoate] was fed at 5000, 15,000, or 35,000 ppm to Crl:CD(SD) rats over two generations. Reduced body weights were observed at all dose levels. Sustained effect on body weight gain at 35,000 ppm in the F0 and F1 parental animals was associated with lower feed efficiency, soft stool, and slightly lower numbers of implantation sites. Lower numbers of pups born and live litter size at 35,000 ppm were considered secondary to slightly lower numbers of former implantation sites in the dams. Spermatogenic endpoints, estrous cyclicity, reproductive performance, mean gestation length, and parturition were unaffected in the F0 and F1 generations. There were no effects on F1 and F2 generation postnatal survival. Reduced pre-weaning pup body weights at 35,000 ppm resulted in lower F1 and F2 body weights at study termination. Slight delays in pubertal landmarks in the F1 offspring were considered secondary to the reduced pup body weights. The no-observed-adverse-effect level (NOAEL) was 15,000 ppm for systemic, reproductive, and neonatal effects based on test article-related effects on body weight and food efficiency, slight decrease in maternal implantation sites and corresponding reduction in live litter size, and reductions in pre-weaning pup body weights at 35,000 ppm.
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Affiliation(s)
| | | | | | - Marisa O Rihner
- Toxicology Regulatory Services, 2365 Hunters Way, Charlottesville, VA 22911, USA.
| | - Andrey I Nikiforov
- Toxicology Regulatory Services, 2365 Hunters Way, Charlottesville, VA 22911, USA.
| | - Eddie D Sloter
- WIL Research Laboratories, 1407 George Road Ashland, OH 44805, USA.
| | - Stephen B Harris
- ReproTox Consulting, Inc. d/b/a/ Stephen B. Harris Group, 6109 Madra Ave., San Diego, CA, 92120, USA.
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Aydilek N, Varisli O, Kocyigit A, Taskin A, Kaya MS. Effect of dietary restriction on sperm characteristic and oxidative status on testicular tissue in young rats exposed to long-term heat stress. Andrologia 2014; 47:1055-61. [DOI: 10.1111/and.12377] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2014] [Indexed: 11/28/2022] Open
Affiliation(s)
- N. Aydilek
- Department of Physiology; Faculty of Veterinary Medicine; Harran University; Sanliurfa Turkey
- Department of Physiology; Faculty of Veterinary Medicine; Dicle University; Diyarbakir Turkey
| | - O. Varisli
- Department of Reproduction and Artificial Insemination; Faculty of Veterinary Medicine; Harran University; Sanliurfa Turkey
| | - A. Kocyigit
- Department of Biochemistry; Faculty of Medicine; Harran University; Sanliurfa Turkey
| | - A. Taskin
- Department of Biochemistry; Faculty of Medicine; Harran University; Sanliurfa Turkey
| | - M. S. Kaya
- Department of Physiology; Faculty of Veterinary Medicine; Dicle University; Diyarbakir Turkey
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DeSesso JM, Scialli AR, White TEK, Breckenridge CB. Multigeneration reproduction and male developmental toxicity studies on atrazine in rats. ACTA ACUST UNITED AC 2014; 101:237-53. [PMID: 24797874 PMCID: PMC4301022 DOI: 10.1002/bdrb.21106] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/11/2014] [Accepted: 02/12/2014] [Indexed: 01/03/2023]
Abstract
BACKGROUND Reproductive toxicity of Atrazine (ATR) was evaluated in two rat multigenerational studies. Development of male reproductive parameters was evaluated in separate studies after prenatal or postnatal exposure. METHODS In multigenerational studies, rats received dietary concentrations of 0, 10, 50, 100 or 500 ppm ATR. In separate studies in female rats, ATR was administered by gavage at 0, 1, 5, 25 or 125 mg/kg/day during pregnancy (GD6–21) or lactation (LD2–21). Plasma testosterone concentration, testicular and epididymal weights, and sperm counts were measured in male offspring on PND70 and 170. RESULTS In the multigenerational studies, parental systemic toxicity occurred at 500 ppm (38.7 mg/kg/day), but reproductive endpoints were unaffected. In the prenatal study, maternal toxicity and embryo-fetal mortality occurred at 125 mg/kg/day. In male offspring, testosterone levels and sperm counts were unaffected, although the percentage of abnormal sperm increased at 125 mg/kg/day (PND 70) and 25 mg/kg/day (PND170). In the postnatal study, maternal toxicity and reduced body weights of male offspring occurred at 125 mg/kg/day. Additionally, reduced testicular (PND70, PND170) and epididymal (PND70) weights and increased numbers of abnormal sperm (PND70, PND170) were seen, but no changes in plasma testosterone or sperm counts. CONCLUSIONS Dietary administration of ATR did not affect rat reproduction up to a parentally toxic dose of 38.7 mg/kg/day. Some effects on male reproductive system development occurred after high dose, bolus administration to dams, but doses were much higher than expected under normal use conditions. Thus, oral RfDs for ATR would be protective for reproductive effects
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Affiliation(s)
- John M DeSesso
- Exponent, Alexandria, Virginia; Georgetown University School of Medicine, Washington, DC
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20
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Nambiar PR, Palanisamy GS, Okerberg C, Wolford A, Walters K, Buckbinder L, Reagan WJ. Toxicities Associated with 1-month Treatment with Propylthiouracil (PTU) and Methimazole (MMI) in Male Rats. Toxicol Pathol 2013; 42:970-83. [DOI: 10.1177/0192623313502708] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thionamides such as propylthiouracil (PTU) and methimazole (MMI) have been used for more than 50 years to treat the more common causes of thyrotoxicosis/hyperthyroidism such as Graves’ disease. Serious adverse effects associated with thionamides in humans include idiosyncratic liver damage, agranulocytosis, aplastic anemia, and vasculitis. Both prospective and retrospective clinical studies with these drugs have failed to identify predictive biomarker for these adverse effects. To assess whether rat is a good model for predicting drug-related adverse events in the liver and in the bone marrow, we conducted a comprehensive study in male rats with multiple doses of PTU and MMI. As expected, euthyroid animals became hypothyroid along with several secondary changes associated with hypothyroidism. There were slight reductions in red blood cell parameters along with some marginal effects on the bone marrow elements. However, there was no evidence of significant neutropenia and liver injury in both PTU-treated and MMI-treated cohorts. MMI-related effects were noted in the seminiferous tubules of the testes. Overall, 1-month daily treatment of euthyroid rats with PTU or MMI resulted in hypothyroidism, minor bone marrow effects, and several secondary effects associated with hypothyroidism, but without any evidence of adverse effects reported in humans including liver injury and agranulocytosis.
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Affiliation(s)
- Prashant R. Nambiar
- Pfizer Inc., Groton, Connecticut, USA
- Both Prashant R. Nambiar and Gopinath S. Palanisamy contributed equally to the article
| | - Gopinath S. Palanisamy
- Pfizer Inc., Groton, Connecticut, USA
- Both Prashant R. Nambiar and Gopinath S. Palanisamy contributed equally to the article
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21
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Houpt JT, Leach GJ, Williams LR, Johnson MS, Reddy G. Toxicity Assessment of 4-Amino-2-Nitrotoluene. Int J Toxicol 2013; 32:113-22. [DOI: 10.1177/1091581813480408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
4-Amino-2-nitrotoluene (4A2NT; CAS 119-32-4) is a degradation product of 2,4-dinitrotoluene. The toxicity data on 4A2NT are limited. Therefore, we collected toxicity data from rats to assess environmental and human health effects from exposures. The approximate lethal dose for both sexes was 5000 mg/kg. A 14-day toxicity study in rats was conducted with 4A2NT in the feed at concentrations of 0, 125, 250, 500, 1000, and 2000 ppm. Based on a 14-day oral dose range toxicity study with 4A2NT in the feed, 2000 ppm was selected as highest concentration for a subsequent 90-day study. An oral 90-day subchronic toxicity study in rats was conducted with concentrations of 0, 500, 1000, or 2000 ppm of 4A2NT in the feed. The calculated consumed doses of 4A2NT in the feed were 0, 27, 52, or 115 mg/kg/d for males and 0, 32, 65, or 138 mg/kg/d for females. A no-observed adverse effect level could not be determined. The lowest observed adverse effect level was 27 mg/kg/d for males and 32 mg/kg/d for female rats based upon decreased body weight gain. The decreased body weight gain in male rats was the most sensitive adverse event observed in this study and was used to derive a benchmark dose (BMD). A BMD of 23.1 mg/kg/d and BMD with 10% effect level of 15.5 mg/kg/d were calculated for male rats, which were used to derive an oral reference dose (RfD). The human RfD of 1.26 μg/kg/d was derived using current United States Environmental Protection Agency guidelines.
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Affiliation(s)
- John T. Houpt
- US Army Public Health Command, Army Institute of Public Health, Toxicology Portfolio, Aberdeen Proving Ground, MD, USA
| | - Glenn J. Leach
- US Army Public Health Command, Army Institute of Public Health, Toxicology Portfolio, Aberdeen Proving Ground, MD, USA
| | - Larry R. Williams
- US Army Public Health Command, Army Institute of Public Health, Toxicology Portfolio, Aberdeen Proving Ground, MD, USA
| | - Mark S. Johnson
- US Army Public Health Command, Army Institute of Public Health, Toxicology Portfolio, Aberdeen Proving Ground, MD, USA
| | - Gunda Reddy
- US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD, USA
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Everds NE, Snyder PW, Bailey KL, Bolon B, Creasy DM, Foley GL, Rosol TJ, Sellers T. Interpreting Stress Responses during Routine Toxicity Studies. Toxicol Pathol 2013; 41:560-614. [DOI: 10.1177/0192623312466452] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Stress often occurs during toxicity studies. The perception of sensory stimuli as stressful primarily results in catecholamine release and activation of the hypothalamic–pituitary–adrenal (HPA) axis to increase serum glucocorticoid concentrations. Downstream effects of these neuroendocrine signals may include decreased total body weights or body weight gain; food consumption and activity; altered organ weights (e.g., thymus, spleen, adrenal); lymphocyte depletion in thymus and spleen; altered circulating leukocyte counts (e.g., increased neutrophils with decreased lymphocytes and eosinophils); and altered reproductive functions. Typically, only some of these findings occur in a given study. Stress responses should be interpreted as secondary (indirect) rather than primary (direct) test article–related findings. Determining whether effects are the result of stress requires a weight-of-evidence approach. The evaluation and interpretation of routinely collected data (standard in-life, clinical pathology, and anatomic pathology endpoints) are appropriate and generally sufficient to assess whether or not changes are secondary to stress. The impact of possible stress-induced effects on data interpretation can partially be mitigated by toxicity study designs that use appropriate control groups (e.g., cohorts treated with vehicle and subjected to the same procedures as those dosed with test article), housing that minimizes isolation and offers environmental enrichment, and experimental procedures that minimize stress and sampling and analytical bias. This article is a comprehensive overview of the biological aspects of the stress response, beginning with a Summary (Section 1) and an Introduction (Section 2) that describes the historical and conventional methods used to characterize acute and chronic stress responses. These sections are followed by reviews of the primary systems and parameters that regulate and/or are influenced by stress, with an emphasis on parameters evaluated in toxicity studies: In-life Procedures (Section 3), Nervous System (Section 4), Endocrine System (Section 5), Reproductive System (Section 6), Clinical Pathology (Section 7), and Immune System (Section 8). The paper concludes (Section 9) with a brief discussion on Minimizing Stress-Related Effects (9.1.), and a final section explaining why Parameters routinely measured are appropriate for assessing the role of stress in toxicology studies (9.2.).
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Affiliation(s)
| | | | - Keith L. Bailey
- Oklahoma Animal Disease Diagnostic Laboratory, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Brad Bolon
- Department of Veterinary Biosciences and the Comparative Pathology and Mouse Phenotyping Shared Resource, The Ohio State University, Columbus, Ohio, USA
| | | | | | - Thomas J. Rosol
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
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Creasy D, Bube A, de Rijk E, Kandori H, Kuwahara M, Masson R, Nolte T, Reams R, Regan K, Rehm S, Rogerson P, Whitney K. Proliferative and nonproliferative lesions of the rat and mouse male reproductive system. Toxicol Pathol 2013; 40:40S-121S. [PMID: 22949412 DOI: 10.1177/0192623312454337] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature and differential diagnosis for classifying microscopic lesions observed in the male reproductive system of laboratory rats and mice, with color microphotographs illustrating examples of some lesions. The standardized nomenclature presented in this document is also available for society members electronically on the Internet (http://goreni.org). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous and aging lesions as well as lesions induced by exposure to test materials. A widely accepted and utilized international harmonization of nomenclature for lesions of the male reproductive system in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists.
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Affiliation(s)
- Dianne Creasy
- Huntingdon Life Sciences, East Millstone, New Jersey 08875, USA.
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Heuser A, Mecklenburg L, Ockert D, Kohler M, Kemkowski J. Selective inhibition of PDE4 in Wistar rats can lead to dilatation in testis, efferent ducts, and epididymis and subsequent formation of sperm granulomas. Toxicol Pathol 2012. [PMID: 23197197 DOI: 10.1177/0192623312463783] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Testicular tubular dilatation and degeneration and epididymal sperm granulomas were frequently seen in 4-week toxicity studies using different phosphodiesterase-4 (PDE4) inhibitors in Wistar rats, including the prototypic PDE4 inhibitor BYK169171. To investigate the pathogenesis of testicular and epididymal lesions, a time course study with BYK169171 was conducted with sequential necropsies after 7, 14, 21, and 28 days of treatment. After 7 days, a dilatation of efferent ducts and of the initial segment of the epididymis and a subacute interstitial inflammation were seen followed by a diffuse dilatation of seminiferous tubules in the testis. Dilatation and inflammation were most pronounced after 14 days. Single animals also exhibited vascular necrosis in the inflamed interstitium. Although dilatation decreased later in the study, the incidence and severity of tubular degeneration increased from 14 days onward. Sperm granulomas developed in efferent ducts and in the caput and cauda of the epididymis after 14 days. Our results demonstrate a clear time course of PDE4 inhibition-induced lesions, with dilatation preceding sperm granuloma formation. We conclude that the most likely mechanism of toxicity is a disturbance of fluid homeostasis in efferent and epididymal ducts resulting in abnormal luminal fluid and sperm contents, epithelial damage at specific sites of the excurrent duct system, sperm leakage, and granuloma formation.
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Affiliation(s)
- Anke Heuser
- Institute for Pharmacology and Preclinical Drug Safety (IPAS), Nycomed GmbH (Nycomed: A Takeda Company), Barsbüttel, Germany.
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Bukovetzky E, Fares F, Schwimmer H, Haim A. Reproductive and metabolic responses of desert adapted common spiny male mice (Acomys cahirinus) to vasopressin treatment. Comp Biochem Physiol A Mol Integr Physiol 2012; 162:349-56. [DOI: 10.1016/j.cbpa.2012.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 04/08/2012] [Accepted: 04/09/2012] [Indexed: 10/28/2022]
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Chapin RE, Creasy DM. Assessment of circulating hormones in regulatory toxicity studies II. Male reproductive hormones. Toxicol Pathol 2012; 40:1063-78. [PMID: 22552397 DOI: 10.1177/0192623312443321] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
When test article-related testicular toxicity or Leydig cell tumors are identified in nonclinical studies, the measurement of circulating hormones such as luteinizing hormone, follicle-stimulating hormone, inhibin, testosterone, or prolactin is often considered in order to aid mechanistic investigations or to identify potential biomarkers in man. Although some hormone levels are relatively constant, others are subject to wide variability owing to pulsatility of secretion, diurnal rhythms, and stress. To avoid being misled, it is important that this variation is factored into any study design that includes hormone measurements. Since all these possibilities start from the pathologist's reading of the tissue sections, we begin with a review of the morphologic changes that are tied to underlying alterations in hormones. We then provide the reader with basic information and representative hormone data, including coefficients of variation, for the major male reproductive hormones in the three main nonclinical species (rats, dogs, and cynomolgus monkeys). Power and probability tables for rats and dogs allow estimates of the number of animals or samples needed to provide a given likelihood of detecting a hormonal change of a given size. More importantly, we highlight the variability of this process and the real value in readers developing this information at their own site.
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Affiliation(s)
- Robert E Chapin
- Pfizer Global R&D, Developmental and Reproductive Toxicology Center of Expertise, Groton, CT 06340, USA.
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Sasaki JC, Chapin RE, Hall DG, Breslin W, Moffit J, Saldutti L, Enright B, Seger M, Jarvi K, Hixon M, Mitchard T, Kim JH. Incidence and nature of testicular toxicity findings in pharmaceutical development. ACTA ACUST UNITED AC 2012; 92:511-25. [PMID: 22162370 DOI: 10.1002/bdrb.20338] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Testicular toxicity (TT) is a sporadic and challenging issue in pharmaceutical drug development. Efforts to develop TT screening assays or biomarkers have been overshadowed by consortium efforts to predict drug-induced toxicities such as hepatic injury, which are encountered more frequently. METHODS To gauge the current state of the field and to prioritize future TT activities, the International Life Sciences Institute-Health and Environmental Sciences Institute Developmental and Reproductive Toxicology (DART) Technical Committee sponsored a survey to better understand the incidence and nature of TT findings encountered during drug development. RESULTS Highlights from the 16 survey respondents include: (1) Although preclinical TT was encountered relatively infrequently, half of the participants observed repeated problems with TT during pharmaceutical development, (2) despite control measures such as use of sexually mature animals to diminish confounding effects of spurious lesions, interpretation of TT remains a challenge, (3) "traditional" evaluation tools such as hormonal monitoring and newer approaches such as -omics are utilized to investigate testicular changes, and (4) an understanding of the risk and relevance of TT findings is achieved through joint consideration of factors such as species specificity, potential mode of action, and safety margins. CONCLUSIONS TT remains a relatively uncommon but persistent challenge in pharmaceutical development. Although current preclinical TT approaches appear to be effective in limiting the occurrence of pharmaceutical candidate attrition in clinical trials, improved biomarker or screening platforms would allow companies to identify TT at an earlier stage, thus decreasing the time and resources expended on safety evaluation of pharmaceutical candidates.
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Affiliation(s)
- Jennifer C Sasaki
- Johnson & Johnson Pharmaceutical Research and Development, Raritan, New Jersey.
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28
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Lent EM, Crouse LCB, Quinn MJ, Wallace SM. Comparison of the Repeated Dose Toxicity of Isomers of Dinitrotoluene. Int J Toxicol 2012; 31:143-57. [DOI: 10.1177/1091581811434645] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dinitrotoluene (DNT) is a nitroaromatic explosive used in propellant mixtures and in the production of plastics. Isomers of DNT were administered daily via oral gavage to male Sprague-Dawley rats for 14 days to determine the subacute toxicity of individual isomers of DNT. The 3,5-DNT isomer was the most toxic isomer, inducing weight loss and mortality within 3 days. Cyanosis and anemia were observed for all isomers. Exposure to 2,4-, 2,6-, and 3,5-DNT resulted in decreased testes mass and degenerative histopathological changes. Increased splenic mass was observed for 2,4-, 2,6-, and 2,5-DNT. Extramedullary hematopoiesis of the spleen was noted for all isomers, while lymphoid hyperplasia of the spleen was noted for all isomers except 2,5-DNT. Increased liver mass was observed for 2,3-DNT and 3,4-DNT. Hepatocellular lesions were observed for 2,6-DNT and 2,4-DNT. Neurotoxic effects were noted for 3,4-DNT, 2,4-DNT, and 3,5-DNT.
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Affiliation(s)
- Emily May Lent
- US Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD, USA
| | - Lee C. B. Crouse
- US Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD, USA
| | - Michael J. Quinn
- US Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD, USA
| | - Shannon M. Wallace
- US Army Public Health Command, Toxicology Portfolio, Aberdeen Proving Ground, MD, USA
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Science based guidance for the assessment of endocrine disrupting properties of chemicals. Regul Toxicol Pharmacol 2011; 59:37-46. [DOI: 10.1016/j.yrtph.2010.09.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 08/06/2010] [Accepted: 09/10/2010] [Indexed: 11/23/2022]
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30
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Pubertal cadmium exposure impairs testicular development and spermatogenesis via disrupting testicular testosterone synthesis in adult mice. Reprod Toxicol 2010; 29:176-83. [DOI: 10.1016/j.reprotox.2009.10.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2009] [Revised: 10/11/2009] [Accepted: 10/28/2009] [Indexed: 11/17/2022]
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31
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Ethics of feeding: the omnivore dilemma. Anim Welf 2010. [DOI: 10.1017/s0962728600001147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
AbstractThe way in which animals are fed is an important aspect of their welfare. Not only does food provide the energy and nutrients vital for survival, but feeding is also associated with a number of other factors contributing to the well-being of animals. The feeding method can determine the animals’ abilities to fulfil basic behavioural needs, such as foraging. The aim of this paper is to review and discuss the dilemma of choosing between ad libitum feeding (AL) and dietary restriction (DR). AL can produce obese individuals with severe health problems, though it does appear to be compatible with welfare-friendly management systems. On the other hand, DR is often associated with improved physical health and longevity but can leave animals suffering from hunger, frustration or aggression. The species discussed are the laboratory rat, pigs and poultry all of which are omnivores sharing many characteristics in their eating habits. The welfare implications of different feeding methods depend upon the definition of welfare used. Based on a definition of welfare in terms of functioning, DR could be considered the best way to feed animals, because it results in improved physical health and longevity. If welfare is defined in terms of natural living, it is also a requirement for the animal to be able to engage in natural foraging behaviours. From the feelings-based approach, DR can be viewed as preferable only in circumstances when animals are anticipated to live so long that they would otherwise suffer from the negative long-term consequences of AL. It is argued that incentives are needed to make farmers spend resources to ensure that farm animals are allowed to have their foraging-related needs fulfilled. Feeding of laboratory animals creates special dilemmas when it is important either to under- or over-nourish the animals for experimental purposes, in such instances there is a need for Refinement.
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