1
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Görmüş G, Ilgın S, Baysal M, Karaduman AB, Kılıç V, Aydoğan-Kılıç G, Karagöz O, Atlı-Eklioğlu Ö. Risperidone induced reproductive toxicity in male rats targeting leydig cells and hypothalamic-pituitary-gonadal axis by inducing oxidative stress. Andrologia 2020; 53:e13813. [PMID: 33108826 DOI: 10.1111/and.13813] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/13/2020] [Accepted: 07/23/2020] [Indexed: 12/14/2022] Open
Abstract
Risperidone (RIS), a commonly used drug during a lifetime for the treatment of schizophrenia, causes some adverse effects in the male reproductive system; however, there is no comprehensive reproductive toxicity study of RIS. For this purpose, male rats were administered orally for 1.25, 2.5 and 3 mg/kg RIS for 28 days and the sperm count, motility, morphology, DNA damage and the histological changes in testicular tissue were evaluated. Follicle-stimulating hormone (FSH), luteinising hormone (LH) and serum levels of testosterone, which are the main hormonal regulators of reproduction, and testicular glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) levels as the indicators of oxidative stress were determined. Normal sperm morphology was decreased in RIS groups and histopathological degeneration occurred in testis tissue dose-dependently. Serum LH levels were not altered; however, FSH and testosterone levels decreased in the high-dose group. Histopathologic examination showed RIS toxicity targeted Leydig cells, which might be associated with impairment of the hypothalamic-pituitary-gonadal (HPG) axis. GSH levels were decreased and MDA levels were increased in the high-dose group which was evaluated as indicators of oxidative stress. In conclusion, RIS caused reproductive toxicity in male rats by inducing oxidative stress and disrupting hormonal regulation.
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Affiliation(s)
- Gözde Görmüş
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Anadolu University, Eskişehir, Turkey
| | - Sinem Ilgın
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Anadolu University, Eskişehir, Turkey
| | - Merve Baysal
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Anadolu University, Eskişehir, Turkey
| | - Abdullah Burak Karaduman
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Anadolu University, Eskişehir, Turkey
| | - Volkan Kılıç
- Department of Biology, Faculty of Science, Eskişehir Technical University, Eskişehir, Turkey
| | - Gözde Aydoğan-Kılıç
- Department of Biology, Faculty of Science, Eskişehir Technical University, Eskişehir, Turkey
| | - Onur Karagöz
- Department of Biology, Faculty of Science, Eskişehir Technical University, Eskişehir, Turkey
| | - Özlem Atlı-Eklioğlu
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Anadolu University, Eskişehir, Turkey
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2
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Brown NA, Spielmann H, Bechter R, Flint OP, Freeman SJ, Jelínek RJ, Koch E, Nau H, Newall DR, Palmer AK, Renault JY, Repetto MF, Vogel R, Wiger R. Screening Chemicals for Reproductive Toxicity: The Current Alternatives. Altern Lab Anim 2020. [DOI: 10.1177/026119299502300615] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Nigel A. Brown
- MRC Experimental Embryology and Teratology Unit, St. George's Hospital Medical School, Cranmer Terrace, London SW17 ORE, UK
| | | | - Rudolf Bechter
- Sandoz Pharma Limited, Drug Safety Assessment, 4002 Basle, Switzerland
| | - Oliver P. Flint
- Bristol-Myers Squibb, Pharmaceutical Research Institute, 6000 Thompson Road, Syracuse, NY 13221, USA
| | - Stuart J. Freeman
- SmithKline Beecham Consumer Healthcare, St George's Avenue, Weybridge, Surrey KT13 ODE, UK
| | - Richard J. Jelínek
- Department of Histology and Embtyology, 3rd Medical Faculty, Charles University, Ruska 87, 100 00 Prague 10, Czech Republic
| | - Elisabeth Koch
- Sandoz Pharma Limited, Drug Safety Assessment, 4002 Basle, Switzerland
| | - Heinz Nau
- Freie University of Berlin, Institute for Toxicology and Embryopharmacology, Garystrasse 5, 1000 Berlin 33, Germany
| | - Derek R. Newall
- GlaxoWellcome Research and Development, Genetic and Reproductive Toxicology, Ware, Herts. SG12 0DP, UK
| | - Anthony K. Palmer
- Huntingdon Research Centre, Department of Toxicology, Huntingdon, Cambs. PE18 6ES, UK
| | - Jean-Yves Renault
- Rhône-Poulenc Rorer, Drug Safety NW 9, 500 Arcola Road, Collegeville, PA 19426-0107, USA
| | | | | | - Richard Wiger
- National Institute of Public Health, Department of Environmental Medicine, Geitmyrsveien 75, 0462 Oslo 4, Norway
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3
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Scialli AR, Clark RV, Chapin RE. Predictivity of Nonclinical Male Reproductive Findings for Human Effects. Birth Defects Res 2018; 110:17-26. [PMID: 28925605 DOI: 10.1002/bdr2.1102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 07/07/2017] [Indexed: 11/09/2022]
Abstract
BACKGROUND Testing of pharmaceutical products for reproductive toxicity in male laboratory animals is required for registration. METHODS We evaluated whether the results of studies showing male reproductive toxicity in experimental animals was predictive of reproductive effects in men participating in clinical trials. We surveyed companies for information on pharmaceutical candidates that had shown male reproductive toxicity in nonclinical studies for which there was information on male reproductive effects in clinical trials. RESULTS Among 12 pharmaceutical candidates submitted by five companies, only one compound that had shown male reproductive toxicity in experimental animals also demonstrated reproductive toxicity in men. CONCLUSION In this sample of compounds, nonclinical studies appeared to over-predict reproductive toxicity in men. We identified possible reasons for the apparent lack of predictivity of the experimental animal studies. Birth Defects Research 110:17-26, 2018. © 2017 Wiley Periodicals, Inc.
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4
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Stewart J. The relevance of experimental reproductive studies in safety assessment. CURRENT OPINION IN TOXICOLOGY 2017. [DOI: 10.1016/j.cotox.2017.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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5
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Lent EM, Crouse LCB, Jackovitz AM, Carroll EE, Johnson MS. An extended one-generation reproductive toxicity test of 1,2,4-Triazol-5-one (NTO) in rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2016; 79:1159-1178. [PMID: 27754820 DOI: 10.1080/15287394.2016.1219893] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Nitrotriazolone (1,2,4-triazol-5-one; NTO), an insensitive, energetic material used in explosive formulations, induced testicular toxicity and oligospermia in repeated-dose oral toxicity tests in rats. To evaluate whether NTO produces additional reproductive and developmental effects, a modified extended one-generation reproductive toxicity test was conducted. Rats were provided ad libitum access to NTO in drinking water at 0-, 144-, 720-, or 3600-mg/L NTO. Treatment of the parental generation began 2 (females) and 4 (males) wk premating and continued until weaning of litters. Direct dosing of offspring (F1) occurred from weaning through puberty. Pups were counted and weighed on postnatal day (PND) 0/1. Anogenital distance (AGD) was measured on PND 4 and males were examined for presence of nipples on PND 13. F1 offspring were examined daily for attainment of puberty. NTO did not markedly affect measures of fertility, including mating indices, gestation index, litter size, and sex ratio. Seminiferous tubule degeneration or atrophy was observed in P1 and F1 3600-mg/L NTO males. F1 males in the 3600 mg/L group exhibited reduced reproductive organ mass (testes, epididymides, and accessory sex organs). Nipple retention was increased in NTO exposed F1 males compared to controls. Attainment of puberty was delayed by 2.6 d in the 3600-mg/L NTO-exposed males relative to controls. Comparison of the effects of NTO with those of antiandrogens suggests absence of malformations of the genital tract in NTO-exposed males. This study supports previous findings indicating that NTO is a testicular toxicant with male developmental effects that may be secondary to testicular toxicity.
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Affiliation(s)
- Emily May Lent
- a Toxicology Directorate , U.S. Army Public Health Center , Aberdeen Proving Ground , Maryland , USA
| | - Lee C B Crouse
- a Toxicology Directorate , U.S. Army Public Health Center , Aberdeen Proving Ground , Maryland , USA
| | - Allison M Jackovitz
- a Toxicology Directorate , U.S. Army Public Health Center , Aberdeen Proving Ground , Maryland , USA
| | - Erica E Carroll
- a Toxicology Directorate , U.S. Army Public Health Center , Aberdeen Proving Ground , Maryland , USA
| | - Mark S Johnson
- a Toxicology Directorate , U.S. Army Public Health Center , Aberdeen Proving Ground , Maryland , USA
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6
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Timing is everything for sperm assessment in fertility studies. Reprod Toxicol 2016; 64:141-50. [DOI: 10.1016/j.reprotox.2016.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/25/2016] [Accepted: 05/02/2016] [Indexed: 11/19/2022]
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7
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Tani Y, Foster PM, Sills RC, Chan PC, Peddada SD, Nyska A. Epididymal Sperm Granuloma Induced by Chronic Administration of 2-Methylimidazole in B6C3F1 Mice. Toxicol Pathol 2016; 33:313-9. [PMID: 15814360 DOI: 10.1080/01926230590922866] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Two-year mouse and rat bioassay studies of 2-methylimidazole (2-MI) conducted by the National Toxicology Program revealed that epididymal sperm granuloma(SG)s occurred only in male B6C3F1 mice in a dose-related manner. The present study characterized 2-MI-induced SGs in these epididymides. Groups of 50 male B6C3F1 mice were fed diets containing 0, 625, 1250, or 2500 ppm 2-MI for 105 weeks; the doses were equivalent to average daily doses of approximately 13, 40, or 130 mg/kg. Testes and epididymides were histopathologically reexamined. 2-Methylimidazole increased the incidence of epididymal SGs (0%, 0%, 6%, 12%, respectively). Histologically, most of the SGs exhibited rupture of epididymal ducts with focal aggregations of macrophages in interstitia. Lesions occurred in the proximal caput of the epididymis and/or efferent ducts, not in the corpus and cauda. In the testis, incidences of germinal epithelial atrophy (GEA) increased dose-relatedly (2%, 8%, 16%, 28%, respectively). All mice with epididymal SG developed testicular GEA. The grading scores of testicular GEA tended to be more severe in mice with SGs than those without. No epididymal SG or testicular GEA was observed in 6-month-interim-sacrificed mice. The results imply that 2-year treatment of B6C3F1 mice with 2-MI can induce epididymal SGs, primarily followed by more severe testicular GEA. The potential mechanism of SG induction by 2-MI is discussed.
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Affiliation(s)
- Yoshiro Tani
- Laboratory of Experimental Pathology, National Institute of Environmental Sciences, NIH, Research Triangle Park, NC 27709, USA
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8
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Revision of the ICH guideline on detection of toxicity to reproduction for medicinal products: SWOT analysis. Reprod Toxicol 2016; 64:57-63. [PMID: 27046733 DOI: 10.1016/j.reprotox.2016.03.048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 03/29/2016] [Accepted: 03/31/2016] [Indexed: 11/21/2022]
Abstract
SWOT analysis was used to gain insights and perspectives into the revision of the ICH S5(R2) guideline on detection of toxicity to reproduction for medicinal products. The current ICH guideline was rapidly adopted worldwide and has an excellent safety record for more than 20 years. The revised guideline should aim to further improve reproductive and developmental (DART) safety testing for new drugs. Alternative methods to animal experiments should be used whenever possible. Modern technology should be used to obtain high quality data from fewer animals. Additions to the guideline should include considerations on the following: limit dose setting, maternal toxicity, biopharmaceuticals, vaccines, testing strategies by indication, developmental immunotoxicity, and male-mediated developmental toxicity. Emerging issues, such as epigenetics and the microbiome, will most likely pose challenges to DART testing in the future. It is hoped that the new guideline will be adopted even outside the ICH regions.
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9
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Vidal JD, Whitney KM. Morphologic manifestations of testicular and epididymal toxicity. SPERMATOGENESIS 2014; 4:e979099. [PMID: 26413388 DOI: 10.4161/21565562.2014.979099] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 10/16/2014] [Indexed: 11/19/2022]
Abstract
Histopathologic examination of the testis is the most sensitive means to detect effects on spermatogenesis; however, the complexity of testicular histology, interrelatedness of cell types within the testis, and long duration of spermatogenesis can make assessment of a testicular toxicant challenging. A thorough understanding of the histology and morphologic manifestations of response to injury is critical to successfully identify a testicular effect and to begin to understand the underlying mechanism of action. The basic patterns of response to xenobiotic-induced injury to the testis and epididymis are detailed and discussed.
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10
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Evaluating the male and female reproductive toxicity of high-boiling petroleum substances. Regul Toxicol Pharmacol 2013; 67:S60-74. [DOI: 10.1016/j.yrtph.2013.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 04/12/2013] [Accepted: 04/17/2013] [Indexed: 11/17/2022]
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11
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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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12
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Chapin RE, Boekelheide K, Cortvrindt R, van Duursen MBM, Gant T, Jegou B, Marczylo E, van Pelt AMM, Post JN, Roelofs MJE, Schlatt S, Teerds KJ, Toppari J, Piersma AH. Assuring safety without animal testing: the case for the human testis in vitro. Reprod Toxicol 2013; 39:63-8. [PMID: 23612449 DOI: 10.1016/j.reprotox.2013.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/05/2013] [Accepted: 04/04/2013] [Indexed: 12/22/2022]
Abstract
From 15 to 17 June 2011, a dedicated workshop was held on the subject of in vitro models for mammalian spermatogenesis and their applications in toxicological hazard and risk assessment. The workshop was sponsored by the Dutch ASAT initiative (Assuring Safety without Animal Testing), which aims at promoting innovative approaches toward toxicological hazard and risk assessment on the basis of human and in vitro data, and replacement of animal studies. Participants addressed the state of the art regarding human and animal evidence for compound mediated testicular toxicity, reviewed existing alternative assay models, and brainstormed about future approaches, specifically considering tissue engineering. The workshop recognized the specific complexity of testicular function exemplified by dedicated cell types with distinct functionalities, as well as different cell compartments in terms of microenvironment and extracellular matrix components. This complexity hampers quick results in the realm of alternative models. Nevertheless, progress has been achieved in recent years, and innovative approaches in tissue engineering may open new avenues for mimicking testicular function in vitro. Although feasible, significant investment is deemed essential to be able to bring new ideas into practice in the laboratory. For the advancement of in vitro testicular toxicity testing, one of the most sensitive end points in regulatory reproductive toxicity testing, such an investment is highly desirable.
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Affiliation(s)
- Robert E Chapin
- Drug Safety R&D, Pfizer, Inc., Eastern Point Road, Groton, CT 06340, USA.
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13
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Mitchard T, Jarvis P, Stewart J. Assessment of Male Rodent Fertility in General Toxicology 6-Month Studies. ACTA ACUST UNITED AC 2012; 95:410-20. [DOI: 10.1002/bdrb.21030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 10/25/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Terri Mitchard
- AstraZeneca Pharmaceuticals; Alderley Park, Macclesfield; Cheshire; United Kingdom
| | - Philip Jarvis
- AstraZeneca Pharmaceuticals; Alderley Park, Macclesfield; Cheshire; United Kingdom
| | - Jane Stewart
- AstraZeneca Pharmaceuticals; Alderley Park, Macclesfield; Cheshire; United Kingdom
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14
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Ranawat P, Kaushik G, Saikia UN, Pathak CM, Khanduja KL. Quercetin impairs the reproductive potential of male mice. Andrologia 2012; 45:56-65. [DOI: 10.1111/j.1439-0272.2012.01311.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2012] [Indexed: 01/29/2023] Open
Affiliation(s)
- P. Ranawat
- Department of Biophysics; Post Graduate Institute of Medical Education and Research; Chandigarh; India
| | - G. Kaushik
- Department of Biophysics; Post Graduate Institute of Medical Education and Research; Chandigarh; India
| | - U. N. Saikia
- Department of Histopathology; Post Graduate Institute of Medical Education and Research; Chandigarh; India
| | - C. M. Pathak
- Department of Biophysics; Post Graduate Institute of Medical Education and Research; Chandigarh; India
| | - K. L. Khanduja
- Department of Biophysics; Post Graduate Institute of Medical Education and Research; Chandigarh; India
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15
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Aulmann W. Assessment of reproductive toxicity under REACH. Regul Toxicol Pharmacol 2012; 63:286-90. [PMID: 22475931 DOI: 10.1016/j.yrtph.2012.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 02/29/2012] [Accepted: 03/06/2012] [Indexed: 10/28/2022]
Abstract
The European REACH regulation requires the evaluation of reproductive toxicity in screening tests according to OECD TG 421 and 422 for substances above the tonnage level of 10 tons/year. The overall aim of this paper is to increase flexibility in combination with a reduced number of experimental animals. Therefore, in contrast to the existing approach the registrant should have the possibility to file a dossier for a substance at the level of 10 tons/year and above also on the basis of data from a developmental toxicity study (OECD TG 414) plus a full-scale subacute toxicity study (OECD TG 407 according to the 1995 protocol). The proposed new test strategy takes into account overall considerations of duty of care and animal welfare. It enables an assessment of developmental toxicity on a definitive instead of a screening level. Registrants should be allowed to select between these two options, either the existing approach (OECD TG 421/407 and alternatively TG 422) or the approach proposed in this paper (OECD TG 407 plus TG 414).
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Affiliation(s)
- Walter Aulmann
- Ecolab Deutschland GmbH, Reisholzer Werftstr. 38-42, 40554 Düsseldorf, Germany.
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16
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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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17
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Creasy DM. Histopathology of the male reproductive system II: interpretation. ACTA ACUST UNITED AC 2011; Chapter 16:Unit16.4. [PMID: 20963756 DOI: 10.1002/0471140856.tx1604s13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Histopathology is acknowledged as the most sensitive endpoint for detecting testicular toxicity. However, identification and interpretation of chemically induced changes in the testis require fundamental knowledge of spermatogenesis, its dynamics and regulation. Changes in the rest of the reproductive tract are also frequently inter-related, being the result of or cause of disturbance in testicular spermatogenesis. This unit provides practical guidelines on how to evaluate testicular histopathology and how to utilize staging in a qualitative evaluation. It also provides an overview of the most common chemically induced lesions and their potential significance with respect to etiology and functional consequences.
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18
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Orazizadeh M, Khorsandi LS, Hashemitabar M. Toxic effects of dexamethasone on mouse testicular germ cells. Andrologia 2010; 42:247-53. [DOI: 10.1111/j.1439-0272.2009.00985.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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19
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Dekant W, Melching-Kollmuß S, Kalberlah F. Toxicity assessment strategies, data requirements, and risk assessment approaches to derive health based guidance values for non-relevant metabolites of plant protection products. Regul Toxicol Pharmacol 2010; 56:135-42. [DOI: 10.1016/j.yrtph.2009.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 09/28/2009] [Accepted: 10/22/2009] [Indexed: 10/20/2022]
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20
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Lerman SA, Hew KW, Stewart J, Stump DG, Wise LD. The nonclinical fertility study design for pharmaceuticals. ACTA ACUST UNITED AC 2009; 86:429-36. [DOI: 10.1002/bdrb.20221] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Barrow PC. Reproductive toxicity testing for pharmaceuticals under ICH. Reprod Toxicol 2009; 28:172-9. [DOI: 10.1016/j.reprotox.2009.03.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 03/30/2009] [Accepted: 03/31/2009] [Indexed: 11/28/2022]
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22
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Cooper RL. Current developments in reproductive toxicity testing of pesticides. Reprod Toxicol 2009; 28:180-7. [DOI: 10.1016/j.reprotox.2009.04.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 04/20/2009] [Accepted: 04/22/2009] [Indexed: 11/15/2022]
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23
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Grindon C, Combes R, Cronin MT, Roberts DW, Garrod JF. Integrated Decision-tree Testing Strategies for Developmental and Reproductive Toxicity with Respect to the Requirements of the EU REACH Legislation. Altern Lab Anim 2008; 36 Suppl 1:123-38. [DOI: 10.1177/026119290803601s10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Liverpool John Moores University and FRAME conducted a research project, sponsored by Defra, on the status of alternatives to animal testing with regard to the European Union REACH (Registration, Evaluation and Authorisation of Chemicals) system for the safety testing and risk assessment of chemicals. The project covered all the main toxicity endpoints associated with the REACH system. This paper focuses on the prospects for the use of alternative methods (both in vitro and in silico) in developmental and reproductive toxicity testing. It considers many tests based on primary cells and cell lines, and the available expert systems and QSARs for developmental and reproductive toxicity, and also covers tests for endocrine disruption. Ways in which reduction and refinement measures can be used are also discussed, particularly the use of an enhanced one-generation reproductive study, which could potentially replace the two-generation study, and therefore considerably reduce the number of animals required in reproductive toxicity. Decision-tree style integrated testing strategies are also proposed for developmental and reproductive toxicity and for endocrine disruption, followed by a number of recommendations for the future facilitation of developmental and reproductive toxicity testing, with respect to human risk assessment.
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Affiliation(s)
| | | | - Mark T.D. Cronin
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
| | - David W. Roberts
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
| | - John F. Garrod
- Chemicals and Nanotechnologies Division, Defra, London, UK
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Goedken MJ, Kerlin RL, Morton D. Spontaneous and Age-Related Testicular Findings in Beagle Dogs. Toxicol Pathol 2008; 36:465-71. [DOI: 10.1177/0192623308315670] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study was conducted to characterize spontaneous testicular and epididymal microscopic findings in eighty control beagle dogs from toxicity studies. Hypospermatogenesis, characterized by randomly scattered missing spermatids and/or spermatocytes within seminiferous tubules, was observed in 75% of dogs six to seven months of age and declined to fewer than 10% in dogs over eleven months of age. Atrophy/hypoplasia of seminiferous tubules, characterized by subcapsular triangular clusters of tubules containing no germ cells, was observed in 25 to 40% of dogs under twelve months old, decreasing with age to 14 to 17% in dogs twelve to thirty-six months old. Retained spermatids, multinucleate giant cells, intracytoplasmic vacuoles (presumably in Sertoli cells), and swollen spermatocytes were common findings of minimal severity. Six- and seven-month-old dogs had lower testicular weights, less filling of the epididymal tails with sperm, and a two-fold higher incidence of abnormal epididymal content compared to dogs more than eight months of age. Most male beagles were histologically sexually mature by eight to nine months of age. This study confirms published reports that dogs at least ten months of age at necropsy usually are adequate for routine microscopic evaluation of the testes. If evaluation of spermatogenesis is critical, the incidental findings can be minimized by using males over twelve months of age.
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Grindon C, Combes R, Cronin MT, Roberts DW, Garrod JF. Integrated Decision-tree Testing Strategies for Developmental and Reproductive Toxicity with Respect to the Requirements of the EU REACH Legislation. Altern Lab Anim 2008. [DOI: 10.1177/026119290803600108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Liverpool John Moores University and FRAME conducted a research project, sponsored by Defra, on the status of alternatives to animal testing with regard to the European Union REACH (Registration, Evaluation and Authorisation of Chemicals) system for the safety testing and risk assessment of chemicals. The project covered all the main toxicity endpoints associated with the REACH system. This paper focuses on the prospects for the use of alternative methods (both in vitro and in silico) in developmental and reproductive toxicity testing. It considers many tests based on primary cells and cell lines, and the available expert systems and QSARs for developmental and reproductive toxicity, and also covers tests for endocrine disruption. Ways in which reduction and refinement measures can be used are also discussed, particularly the use of an enhanced one-generation reproductive study, which could potentially replace the two-generation study, and therefore considerably reduce the number of animals required in reproductive toxicity. Decision-tree style integrated testing strategies are also proposed for developmental and reproductive toxicity and for endocrine disruption, followed by a number of recommendations for the future facilitation of developmental and reproductive toxicity testing, with respect to human risk assessment.
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Affiliation(s)
| | | | - Mark T.D. Cronin
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
| | - David W. Roberts
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
| | - John F. Garrod
- Chemicals and Nanotechnologies Division, Defra, London, UK
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26
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Pelletier G, Masson S, Wang YL, Wade MG, Mohottalage S, Kumarathasan P, Vincent R, Poon R, Chu I. Proteomic investigation of 1,6-dimethoxyhexane testicular toxicity. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2007; 24:129-133. [PMID: 21783800 DOI: 10.1016/j.etap.2007.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 04/04/2007] [Accepted: 04/09/2007] [Indexed: 05/31/2023]
Abstract
The aliphatic ether 1,6-dimethoxyhexane (DMH) was previously identified as a testicular toxicant. Testis protein extracts from control and DMH-treated rats were subjected to two-dimensional gel electrophoresis for comparison of protein expression profiles. MALDI-ToF peptide mass fingerprinting of differentially expressed proteins resulted in the conclusive identification of heat shock-related 70kDa protein 2 (HSP70.2), 60kDa heat shock protein, mitochondrial precursor (HSP60) and protein disulfide isomerase A3 precursor (ERp60). The potential involvement of these proteins in chemically induced perturbation of spermatogenesis and their utility as biomarkers of testicular toxicity are discussed in light of the knowledge currently available from the literature.
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Affiliation(s)
- Guillaume Pelletier
- Systemic Toxicology and Pharmacokinetics Section, Environmental and Occupational Toxicology Division, Environmental Health Sciences Bureau, Health Canada
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27
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Buschmann J. Critical aspects in reproductive and developmental toxicity testing of environmental chemicals. Reprod Toxicol 2006; 22:157-63. [PMID: 16782303 DOI: 10.1016/j.reprotox.2006.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Revised: 03/20/2006] [Accepted: 03/21/2006] [Indexed: 11/20/2022]
Abstract
The process of toxicity testing of environmental chemicals is ruled by a framework of guidelines (OECD, OPPTS, etc.). The present paper will describe the process from the biological tests for environmental chemicals up to potential labelling and will focus on some critical aspects in this cascade of events. It is also the aim of this paper to give an overview of the existing documents and draft documents relevant for this field and available in the internet. Based on the current situation, the following points are discussed as critical issues: life stage considerations and their implications on testing, usefulness of investigations in juvenile animals, requirements for ADME studies, design and endpoints in fertility studies, use and usefulness of developmental milestones, performance of special studies versus one-study-design, considerations on transplacental carcinogenicity and early aging, significance of maternal/parental toxicity, application of triggers to justify studies, inclusion of new endpoints into test guidelines, and test strategies applied. Based on this, the usefulness of risk considerations in the current EU classification system for toxicity to reproduction as well as potency considerations will be discussed and suggestions will be made to improve the basic requirements for chemical testing which have remained relatively unchanged over the past 20 years.
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Affiliation(s)
- Jochen Buschmann
- Fraunhofer Institute of Toxicology and Experimental Medicine, Nikolai-Fuchs-Str. 1, 30625 Hannover, Germany.
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28
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Kihaile PE, Aoki K, Kimura N, Pei W, Misumi J. Are sperm parameters the best indicator of 2,5-hexanedione reproductive toxicity in male rats? Reprod Toxicol 2005; 20:515-9. [PMID: 15941647 DOI: 10.1016/j.reprotox.2005.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2003] [Revised: 02/02/2005] [Accepted: 03/02/2005] [Indexed: 11/26/2022]
Abstract
In this study on 40 male Wistar rats of approximately 3-weeks-old, the effects of 2,5-hexanedione on sperm principal parameters were examined by subcutaneously administering 100, 200 and 400 mg/(kgday) for 12 weeks. Other indicators of 2,5-hexanedione intoxication were examined: testes, epididymides, body weight, limb paralysis and histology. The sperm motility was adversely affected in all of the three treatment groups. No sperm motility at all was observed in the 200 and 400 mg/(kgday) treatment groups and rapid progressive motility was significantly reduced in the 100 mg/(kgday) group (P<0.05). The sperm concentration and morphology, testes, epididymides and body weight were significantly affected in the 200 and 400 mg/(kgday) groups but not in the 100 mg/(kgday) group (P<0.05). All the rats in the 400 mg/(kgday) group could not move due to leg paralysis, whereas only 50% of the rats in the 200mg/(kgday) group and none in the 100 mg/(kgday) were affected. Histological examination of the testes in the 400, 200 and 100 mg/(kgday) groups revealed Sertoli cell-only syndrome in 70, 30 and 0% of the rats, respectively. In conclusion, this study has shown that sperm motility was the most significantly sensitive indicator of 2,5-hexanedione intoxication in all the treatment groups.
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Affiliation(s)
- Paul E Kihaile
- Division of Preventive Medicine, Department of Human Environmental and Social Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan.
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Reuter U, Heinrich-Hirsch B, Hellwig J, Holzum B, Welsch F. Evaluation of OECD screening tests 421 (reproduction/developmental toxicity screening test) and 422 (combined repeated dose toxicity study with the reproduction/developmental toxicity screening test). Regul Toxicol Pharmacol 2003; 38:17-26. [PMID: 12878050 DOI: 10.1016/s0273-2300(03)00076-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Advisory Committee on Existing Chemicals (BUA) of the Federal Republic of Germany convened a panel with expertise in reproductive and developmental toxicology to evaluate the OECD Screening Tests 421 (Reproduction/Developmental Toxicity Screening Test) and 422 (Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test) with respect to their ability to unmask any potential toxic effects on reproduction. The original assignment for that panel was to "validate" those screening tests. However, the panel members recognized beforehand that this was actually an impossible task because of lack of a sufficient database. Only five chemicals with known reproductive toxicity had been examined following the OECD Screening Test Guidelines 421 or 422. A comparison of these test results with those of the definitive OECD Test Guidelines 414, 415, 416, or additional investigations could, therefore, only have been made with this very limited number of chemicals that had also undergone evaluation by one of the test guidelines cited. In each case biological properties relevant to reproductive toxicity were also indicated by the OECD Screening Tests 421 or 422. This communication reviews the main differences in study design of OECD Screening Test Guidelines 421 and 422 compared to those definitive test guidelines of similar study design for reproduction or developmental toxicity (especially with the one-generation study, OECD Test Guideline 415). The very limited possibilities of detecting late postnatal and postlactational manifestations are emphasized, as is the low statistical power of the OECD Screening Tests 421 and 422. Furthermore, the very limited ability to unmask teratogenicity is delineated. The outcome of screening tests was evaluated based on the results of 57 studies conducted according to the OECD Test Guideline 421 or 422. The test results were categorized according to the incidence of toxic effects on reproduction in the parent animals or their offspring and related to general toxic effects. Based on the ranking of these results, recommendations regarding setting rational priorities for further evaluations of existing chemicals' reproductive hazards are made. In general, the reviewer panel supports the OECD position that the screening tests are useful for initial hazard assessment and can contribute to the decision-making process on setting priorities for further test requirements. The panel also agrees with the OECD statement that the OECD Screening Tests 421 and 422 are neither an alternative to definitive tests (i.e., OECD Test Guidelines 414, 415, and 416) nor are they intended as their replacement.
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Affiliation(s)
- Ulrike Reuter
- BUA-Büro Munich, Technical University of Munich, Hohenbachernstrasse 15-17, 85350 Freising-Weihenstephan, Germany.
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Mangelsdorf I, Buschmann J, Orthen B. Some aspects relating to the evaluation of the effects of chemicals on male fertility. Regul Toxicol Pharmacol 2003; 37:356-69. [PMID: 12758216 DOI: 10.1016/s0273-2300(03)00026-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Reviews and studies on individual compounds were analyzed as to the suitability of different study designs and endpoints for detecting adverse effects of chemicals on male reproduction in animal species. Of the endpoints investigated, the most sensitive proved to be histopathology of the testes. Using refined histopathology, effects could be detected with a high degree of sensitivity as early as 4 weeks after treatment. Other sensitive endpoints were the weights of reproductive organs, including accessory glands, i.e., testis, epididymis, prostate, and of the seminal vesicle, as well as sperm parameters such as sperm count, sperm morphology, and sperm motility. Sperm motility was found to be in some cases more sensitive than histopathology. The above parameters showed a higher sensitivity than fertility parameters. In fact, in most cases, not only one but several endpoints were affected. Continuous breeding studies and 90-day studies with additional measurements of sperm parameters were similarly effective in detecting compounds which affect male fertility. Interspecies extrapolation factors (IEFs) have been derived for the most sensitive endpoints in laboratory animals. If the calculation is based on caloric demand and a sensitive endpoint of reproductive toxicity, many IEFs tend to be about 1, indicating that humans are generally not more susceptible to reproductive toxicants than laboratory animals. With respect to hazard identification, it is possible to detect adverse effects on male reproduction in a standard subacute study with concentrations that produce significant general toxicity. If effects are found, for the risk assessment the NOAEL has to be determined by testing specific sensitive parameters as specified above.
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Affiliation(s)
- Inge Mangelsdorf
- Fraunhofer Institute of Toxicology and Experimental Medicine, Drug Research and Clinical Inhalation, Nikolai-Fuchs-Str. 1, 30625, Hannover, Germany.
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Abstract
The question of whether a 4 or 9 week premating treatment period is more suitable in studies for effects on fertility and early embryonic development, and the extent to which the screening of sperm parameters may contribute to the detection of effects, has been under discussion since the ICH guideline changed in 1994/1995. This study presents a comparison between 4 and 9 weeks treatment with known male reproductive toxicants with regard to sperm motility, count, morphology, abnormal movements and testicular and epididymal histopathology. Mating outcome was examined after 4 weeks treatment. Three compounds with different targets and mechanisms of action were chosen: two testicular toxicants, Pyridoxine and Adriamycin and the epididymal toxicant, alpha-Chlorohydrine. Sperm motility was reduced in males treated with Pyridoxine (markedly) and alpha-Chlorohydrine (slightly) after 4 weeks treatment and in males treated with Adriamycin after 9 weeks treatment. With Pyridoxine and Adriamycin, sperm count was significantly increased after 4 weeks. Histopathological examination after 4 weeks showed characteristic changes leading to marked testicular tubular atrophy at 8/9 weeks, which was confirmed by a significantly reduced sperm count at 8/9 weeks. With alpha-Chlorohydrine, sperm count was not affected and the results of the histopathological examination were equivocal. Changes in sperm morphology were observed after 4/9 weeks of treatment with Pyridoxine. Mating outcome after 4 weeks was markedly affected with both Pyridoxine and alpha-Chlorohydrine, but no effect was observed with Adriamycin. The results of this study indicate that the two testicular toxicants would have been detected as male reproductive toxicants in a 4-week general toxicity study with routine testicular histopathology and examination of sperm parameters, without the need for mating trials. For the epididymal toxicant, alpha-Chlorohydrine, there was slightly reduced sperm motility after 4 weeks treatment, but mating trials were necessary for confirmation of the toxic effect. Without sperm motility examination, this effect would have been missed in early drug development causing problems in clinical studies. Further comparisons of the validity of 4 or 9 weeks treatment require the testing of other compounds with different targets/mechanism of actions, as well as evaluation of dose-response relationships.
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Affiliation(s)
- S Plassmann
- Department of Toxicology, F. Hoffmann-La Roche Ltd., Basel, Switzerland.
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Abstract
Spontaneous testicular lesions were assessed in 50 control purpose-bred male beagle dogs. They were selected from 13 toxicology studies conducted over the period 1988-1999. Age of the dogs at study termination varied from 8-20 months with an average age of 13 months. Regardless of age, the most significant finding was bilateral segmental hypospermatogenesis in 15/50 (30%) of the dogs. Cross sections of tubules with hypospermatogenesis were distributed randomly throughout the testes and were characterized by reduced proportions of germ cells, tubular shrinkage, and Sertoli cell prominence. These changes were occasionally associated with giant cells, with cellular debris, and in 6/15 (40%) with atrophic tubules devoid of germ cells, indicating a degenerative process. Focal subcapsular tubular atrophy or hypoplasia (tubules lined by Sertoli cells only) was also found in 9/35 (26%) of dogs without hypospermatogenesis. Inhibited spermiation with retention of mature sperm in tubules was seen in 6/50 dogs, 3 of which also showed hypospermatogenesis. Other findings of high incidence but low prevalence included tubules with multinucleated giant cells, swollen spermatocytes, or apoptotic germ cells. These latter changes are probably a constituent of normal spermatogenesis. In conclusion, about 30% of control beagle dogs show segmental hypospermatogenesis, which may be associated with degenerative changes, and an additional 18% of the dogs exhibit focal tubular atrophy/hypoplasia in otherwise normal testes. These changes have to be distinguished from compound-related toxic effects.
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Affiliation(s)
- S Rehm
- SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406, USA
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Torner H, Blottner S, Kuhla S, Langhammer M, Alm H, Tuchscherer A. Influence of chlorocholinechloride-treated wheat on selected in vitro fertility parameters in male mice. Reprod Toxicol 1999; 13:399-404. [PMID: 10560589 DOI: 10.1016/s0890-6238(99)00032-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this study was to evaluate the influence of feeding with food and water containing chlorocholinechloride (CCC) on the fertility of male mice in a two-generation study. For this purpose the number of testicular spermatozoa and the relative proportion of primary and secondary spermatocytes involved in spermatogenesis were measured. Furthermore, the fertility of epididymal spermatozoa from tested male mice was investigated in a special in-vitro fertilization system. The experimental food was composed of CCC-treated wheat in the first experiment and CCC-free wheat and water mixed with pure CCC in the second experiment. The CCC residue content in the treated food and water was 0.21 mg/kg and 0.2 mg/L, respectively. Under the influence of feeding with CCC-treated wheat (Experiment 1) the fertilization and cleavage rates of oocytes incubated with spermatozoa from CCC-fed mice were reduced: the fertilization rate 65.1% vs. 21.1% and the cleavage rate 51.9% vs. 20.3%, p < 0.01 (control feeding vs. CCC feeding, respectively). Feeding of sperm donors with pure CCC mixed with untreated wheat pellets or water (Experiment 2) led to a reduction in the fertilization and cleavage rate (control: 60.8%, 32.4%; CCC-food: 29.8%, 12.1%; CCC-water: 30.1%, 10.2%; CCC-food/water: 36.6%, 12.5%; p < 0.01, respectively). The normal course of spermatogenesis was unchanged after the exposure to CCC. Testicular weight, the number of spermatozoa, and the proportion of haploid, diploid, and tetraploid testicular cells were not influenced. However, the functional competence of epididymal spermatozoa from CCC-fed donors was reduced, resulting in a significantly diminished fertilization and cleavage rate in vitro. The results suggest that CCC could interfere with epididymal protein secretion and the process of sperm maturation during passage through the epididymis.
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Affiliation(s)
- H Torner
- Department of Reproductive Biology, Research Institute for the Biology of Farm Animals, Dummerstorf, Germany.
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Blottner S, Frölich K, Roelants H, Streich J, Tataruch F. Influence of environmental cadmium on testicular proliferation in roe deer. Reprod Toxicol 1999; 13:261-7. [PMID: 10453910 DOI: 10.1016/s0890-6238(99)00014-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The influence of cadmium on spermatogenesis in roe deer was studied, comparing animals from areas with high (n = 37) and low (n = 23) cadmium exposure. Testes were evaluated during pre-rut (May) and rut (July/August). During these periods the cadmium accumulation (mg/kg kidney) in polluted regions averaged 3.41 and 3.52 in comparison with 1.61 and 1.81 in controls. Cadmium accumulation was positively correlated with testis weight during both seasons. In May the proliferation (units of tissue polypeptid specific antigen/g parenchyma) was lower in animals with higher cadmium (24.02 compared with 78.20; P < 0.01). During the rut, testicular proliferation and spermatozoa/g testis as well as apoptosis showed no significant changes with increased cadmium contamination. The results suggest delayed proliferation during the pre-rutting period in animals with high cadmium exposure, but other indications of effects on the testis were not significant.
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Affiliation(s)
- S Blottner
- Institute for Zoo Biology and Wildlife Research, Berlin, Germany.
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35
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Claudio L, Bearer CF, Wallinga D. Assessment of the U.S. Environmental Protection Agency methods for identification of hazards to developing organisms, Part I: The reproduction and fertility testing guidelines. Am J Ind Med 1999; 35:543-53. [PMID: 10332507 DOI: 10.1002/(sici)1097-0274(199906)35:6<543::aid-ajim1>3.0.co;2-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Successful reproduction depends on the coordination of many processes, particularly the normal development and subsequent maturation of the sexual organs. The Food Quality Protection Act of 1996 mandates that the U.S. Environmental Protection Agency must protect infants and children from the effects of toxins, including those that affect the reproductive system. Therefore, the Agency finds itself at a critical juncture to make sure that the methods it requires for toxicity testing, the Health Effects Test Guidelines or Series 870 Guidelines, are adequate to determine possible toxicity to children. METHODS AND RESULTS We found that two testing protocols included in the core guidelines assess toxicological effects on developing animals. This article aims to provide a detailed analysis of the protocols included in the Reproduction and Fertility Effects Test Guideline. An accompanying article assesses the Developmental Toxicity Testing Guideline. We conducted this analysis on the basis of whether the test would yield the information needed to adequately determine risk to infants and children. CONCLUSIONS Our analysis concludes that given the limitations inherent in testing for reproduction and fertility effects during development, it is necessary to include a safety factor during risk assessment of chemicals. This action will fulfill the mandate expressed in the FQPA to protect infants and children from environmental hazards.
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Affiliation(s)
- L Claudio
- Division of Environmental and Occupational Medicine, Mount Sinai Medical Center, New York, NY 10029-6574, USA.
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36
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Son HY, Kim YB, Kang BH, Cho SW, Ha CS, Roh JK. Effects of 2-bromopropane on spermatogenesis in the Sprague-Dawley rat. Reprod Toxicol 1999; 13:179-87. [PMID: 10378467 DOI: 10.1016/s0890-6238(99)00005-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In 1995, 2-bromopropane (2-BP) was associated with occupational reproductive and hematopoietic toxicity in Korea. The effect of 2-BP on spermatogenesis, or Leydig cells, has not been determined in adult rats. In the present study, 40 ten-week-old Sprague-Dawley (SD) rats were treated orally with 3.5 g/kg/d of 2-BP for 3 consecutive days. At 1, 3, 5, 7, 14, 28, 42, and 70 d after treatment, testes were perfused with Karnovsky's solution or immersed in Bouin's solution, embedded in plastic or Epon and evaluated with light and electron microscopy. DNA ploidy distributions of testicular suspensions were determined by flow cytometry, which allowed comparison of quantitative spermatogenesis with histopathologic observations. Degeneration of spermatogonia was observed during Stages I-IV in seminiferous tubules on Day 1 after treatment. Spermatocytes, spermatids, Sertoli cells, and Leydig cells appeared normal in the early stage of the study. Whereas spermatid retention in Stages IX-XI was observed on Day 7 after treatment, depletion of spermatocytes and spermatids continued over time, followed by a marked increase of germ cells on Day 42 after treatment. However, the seminiferous tubules did not completely recover by study termination. Leydig cell cellularity increased mildly without any significant morphologic modification at the end of the study. Immunohistochemistry using an antibody against proliferating cell nuclear antigen (PCNA), showed an increased number of immunoreactive Leydig cells in the interstitium. In the flow cytometry analysis, proportions of diploid and tetraploid cells gradually decreased time-dependently until Day 28 after treatment, but showed an increase on Day 42, followed by a decrease on Day 70 after treatment. These data are strengthened by qualitative descriptions of lesions observed by histopathology. These results suggest that a high dose of 2-BP can decrease spermatogenesis by adversely affecting spermatogonia followed by depletion of spermatocytes, spermatids, and spermatozoa, with subsequent testicular atrophy. The atrophied testes may not regenerate completely. The number of Leydig cells may increase mildly with 10 weeks of recovery.
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Affiliation(s)
- H Y Son
- Screening & Toxicology Research Center, Korea Research Institute of Chemical Technology, Taejon, Republic of Korea.
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Hoyt JA, Fisher LF, Swisher DK, Byrd RA, Francis PC. The selective estrogen receptor modulator, raloxifene: reproductive assessments in adult male rats. Reprod Toxicol 1998; 12:223-32. [PMID: 9628547 DOI: 10.1016/s0890-6238(98)00004-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Raloxifene HCl is a nonsteroidal, selective estrogen receptor modulator developed for postmenopausal osteoporosis. Reproductive toxicity of raloxifene was examined in adult male CD rats after the oral administration of doses of 0, 10, 30, or 100 mg/kg/d. In the first study, males (12/group) were treated for 2 weeks followed by 2 weeks without treatment. After dose administration on Day 13, 6 males/group were cohabited with untreated females (1:2) for up to 7 d. Males were killed on Day 14 or 28 (6/group each day). Sperm were collected from the right cauda epididymis and evaluated for relative concentration, motion characteristics, and breakage. The kinetics of spermatogenesis were examined by DNA flow cytometry. The left testis and epididymis were preserved for histopathologic evaluation. Females were examined for reproductive status on Gestation Day 13. In a second study, males (20/group) were treated for 7 weeks (4 weeks prior to cohabitation during a 2-week cohabitation period, and for 1 additional week). Treated males were cohabited with untreated females (1:1). On Gestation Day 20, untreated females were examined for reproductive status and fetuses were examined for viability, weight, gender, and morphology. At necropsy, male reproductive tissues were collected, weighed, and preserved for histopathologic evaluation. In both studies, male body weight gain and food consumption were depressed at all dose levels. There was no indication in either study that raloxifene caused important changes in sperm production, sperm quality, or male reproductive performance at doses as high as 100 mg/kg/d.
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Affiliation(s)
- J A Hoyt
- Toxicology and Drug Disposition, Lilly Research Laboratories, A Division of Eli Lilly and Company, Greenfield, Indiana 46140, USA.
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Stevens JT, Gfeller W, Machemer L, Leist KH. Adequacy of required regulatory hazard testing for the detection of potential hormonal activity of crop protection chemicals. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 1998; 1:59-79. [PMID: 9487093 DOI: 10.1080/10937409809524543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The capacity of some synthetic chemicals, the so-called "endocrine-disrupting chemical," to alter hormonal activity, as well as the adequacy of the testing of chemicals to evaluate this capacity, has been called into question. Among the chemicals indicted have been certain crop protection agents or pesticides. Crop protection chemicals rank among the most closely regulated and thoroughly tested chemicals in use in both the human health and environmental hazard areas. However, it has been proposed that in vitro and in vivo screening tests be used to identify potential endocrine-active chemicals and to supplement or replace required regulatory bioassays. In vitro tests, such as receptor binding, examine a single chemical event, do not measure toxicity, post-receptor-mediated biological response, or the absorption, distribution, metabolism, and elimination of a chemical. Therefore, data derived solely from such a limited testing technique should not be used as a basis for selection of chemicals for making regulatory decisions. In vivo screening tests, such as the uterotrophic assay, which promise to provide a rapid answer to a targeted question, do not capture the complexity of the biological response. As in the case with in vitro tests, results from a single in vivo test, such as a change in uterine weight, should not be used as a basis for regulatory decision making. Further, it has been suggested that such a screening battery should be put into place for ecotoxicity testing. Yet it is well recognized that endocrine-active chemicals that affect fish and wildlife in their natural habitat have been shown to cause similar adverse effects in laboratory test animals. Therefore, these screening tests do not add value to the current regulatory test battery. Evidence is presented that demonstrates that the regulatory safety assessment paradigm has a low likelihood of missing potential endocrine-active chemicals and has served society well.
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Affiliation(s)
- J T Stevens
- Department of Toxicology, Novartis Crop Protection, Inc., Greensboro, NC 27419-8300, USA
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4. Reproductive Toxicity. Hum Exp Toxicol 1997. [DOI: 10.1177/096032719701600103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Harleman JH, Nolte T. Testicular toxicity: regulatory guidelines--the end of formaldehyde fixation? Toxicol Pathol 1997; 25:414-7; discussion 418. [PMID: 9280130 DOI: 10.1177/019262339702500415] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J H Harleman
- Corporate R&D ASTA Medica Group, Institute of Toxicology, Halle/Westfalen, Germany
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Smith PF. Third international conference on harmonization of technical requirements for registration of pharmaceuticals for human use--a toxicologist's perspective. Toxicol Pathol 1996; 24:519-28. [PMID: 8864198 DOI: 10.1177/019262339602400423] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This overview provides a perspective on the ICH process and outcomes based on the third international conference held in Yokohama, Japan, in November/December 1995. It is an attempt to provide awareness of this process to the toxicologic pathology community from the point of view of a practicing toxicologist and meeting attendee and to consolidate much of the information on this process in one place. The ICH process is an active, and ongoing process to improve the standardization of safety assessment testing throughout the world, and further changes will no doubt have occurred by the time this document is published.
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Affiliation(s)
- P F Smith
- Department of Regulatory Drug Safety, G. D. Searle and Company, Skokie, Illinois 60077, USA
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