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Shi L, Li X, Ji Z, Wang Z, Shi Y, Tian X, Wang Z. The reproductive inhibitory effects of levonorgestrel, quinestrol, and EP-1 in Brandt's vole ( Lasiopodomys brandtii). PeerJ 2020; 8:e9140. [PMID: 32566388 PMCID: PMC7293854 DOI: 10.7717/peerj.9140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 04/16/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Rodent pests can inflict devastating impacts on agriculture and the environment, leading to significant economic damage associated with their high species diversity, reproductive rates and adaptability. Fertility control methods could indirectly control rodent pest populations as well as limit ecological consequences and environmental concerns caused by lethal chemical poisons. Brandt's voles, which are common rodent pests found in the grasslands of middle-eastern Inner Mongolia, eastern regions of Mongolia, and some regions of southern Russia, were assessed in the present study. METHODS We evaluated the effects of a 2-mg/kg dose of levonorgestrel and quinestrol and a 1:1 mixture of the two (EP-1) on reproductive behavior as well as changes in the reproductive system, reproductive hormone levels, and toxicity in Brandt's voles. RESULTS Our results revealed that all three fertility control agents can cause reproductive inhibition at a dosage of 2 mg/kg. However, quinestrol caused a greater degree of toxicity, as determined by visible liver damage and reduced expression of the detoxifying molecule CYP1A2. Of the remaining two fertility control agents, EP-1 was superior to levonorgestrel in inhibiting the secretion of follicle-stimulating hormone and causing reproductive inhibition. We believe that these findings could help promote the use of these fertility control agents and, in turn, reduce the use of chemical poisons and limit their detrimental ecological and environmental impacts.
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Affiliation(s)
- Luye Shi
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
- School of Physical Education (Main Campus), Zhengzhou University, Zhengzhou, Henan, China
| | - Xiujuan Li
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Zhihong Ji
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Zishi Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Yuhua Shi
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Xiangyu Tian
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Zhenlong Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
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Berry C. The failure of rodent carcinogenesis as a model for Man. Toxicol Res (Camb) 2018; 7:553-557. [PMID: 30090605 PMCID: PMC6062156 DOI: 10.1039/c7tx00283a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 12/14/2017] [Indexed: 11/21/2022] Open
Abstract
Recent advances in our understanding of the process of carcinogenesis in Man have required revision of our thinking about the classical initiation/promotion sequence; understanding must now encompass the roles of both genetic and epigenetic change, realisation of the importance of the variable genetic backgrounds of the tumour bearers in any group and an understanding of the importance of random genetic events over time. The behavior of tumours, once established, is more complex than has been thought. Current views of the processes involved are not modelled in toxicity testing programmes.
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Affiliation(s)
- Colin Berry
- Queen Mary , London , Mile End Rd , London E1 4NS , UK .
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Harleman JH, Hargreaves A, Andersson H, Kirk S. A Review of the Incidence and Coincidence of Uterine and Mammary Tumors in Wistar and Sprague-Dawley Rats Based on the RITA Database and the Role of Prolactin. Toxicol Pathol 2012; 40:926-30. [DOI: 10.1177/0192623312444621] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Wistar rats are frequently selected for use in carcinogenicity studies because of their advantageous survival rate, which is more favorable than other strains such as the Sprague-Dawley (SD) strain. Uterine and mammary tumors are relatively common spontaneous neoplasms of both strains. We examined the incidence and coincidence of uterine tumors and mammary tumors in control animals of both strains within the RITA database. There was a strong inverse relationship between these tumor types in Wistar rats ( p < .001). A less strong relationship was present in SD rats ( p = .057). This association is likely to be related to prolactin. A short review of the role of prolactin in rats is given. These results are also discussed in the background of nonspecific toxicity at high dose levels in carcinogenicity studies above MTD levels resulting in reduction in body weights of >10%.
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Affiliation(s)
| | - Adam Hargreaves
- Astra Zeneca, Safety Assessment, Mereside Alderley Park, Macclesfield, UK
| | | | - Sarah Kirk
- Astra Zeneca, Safety Assessment, Mereside Alderley Park, Macclesfield, UK
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Ettlin RA, Kuroda J, Plassmann S, Prentice DE. Successful drug development despite adverse preclinical findings part 1: processes to address issues and most important findings. J Toxicol Pathol 2010; 23:189-211. [PMID: 22272031 PMCID: PMC3234634 DOI: 10.1293/tox.23.189] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 09/06/2010] [Indexed: 01/08/2023] Open
Abstract
Unexpected adverse preclinical findings (APFs) are not infrequently encountered during drug development. Such APFs can be functional disturbances such as QT prolongation, morphological toxicity or carcinogenicity. The latter is of particular concern in conjunction with equivocal genotoxicity results. The toxicologic pathologist plays an important role in recognizing these effects, in helping to characterize them, to evaluate their risk for man, and in proposing measures to mitigate the risk particularly in early clinical trials. A careful scientific evaluation is crucial while termination of the development of a potentially useful drug must be avoided. This first part of the review discusses processes to address unexpected APFs and provides an overview over typical APFs in particular classes of drugs. If the mode of action (MoA) by which a drug candidate produces an APF is known, this supports evaluation of its relevance for humans. Tailor-made mechanistic studies, when needed, must be planned carefully to test one or several hypotheses regarding the potential MoA and to provide further data for risk evaluation. Safety considerations are based on exposure at no-observed-adverse-effect levels (NOAEL) of the most sensitive and relevant animal species and guide dose escalation in clinical trials. The availability of early markers of toxicity for monitoring of humans adds further safety to clinical studies. Risk evaluation is concluded by a weight of evidence analysis (WoE) with an array of parameters including drug use, medical need and alternatives on the market. In the second part of this review relevant examples of APFs will be discussed in more detail.
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Affiliation(s)
- Robert A. Ettlin
- Ettlin Consulting Ltd., 14 Mittelweg, 4142 Muenchenstein,
Switzerland
| | - Junji Kuroda
- KISSEI Pharmaceutical Co., Ltd., 2320–1 Maki, Hotaka, Azumino,
Nagano 399-8305, Japan
| | - Stephanie Plassmann
- PreClinical Safety (PCS) Consultants Ltd., 7 Gartenstrasse, 4132
Muttenz, Switzerland
| | - David E. Prentice
- PreClinical Safety (PCS) Consultants Ltd., 7 Gartenstrasse, 4132
Muttenz, Switzerland
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Keenan C, Elmore S, Francke-Carroll S, Kemp R, Kerlin R, Peddada S, Pletcher J, Rinke M, Schmidt SP, Taylor I, Wolf DC. Best practices for use of historical control data of proliferative rodent lesions. Toxicol Pathol 2009; 37:679-93. [PMID: 19454599 DOI: 10.1177/0192623309336154] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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On the interpretation of rat carcinogenicity studies for human PTH(1-34) and human PTH(1-84). J Bone Miner Res 2008; 23:803-11. [PMID: 18435577 DOI: 10.1359/jbmr.080208] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Cancel AM, Smith T, Rehkemper U, Dillberger JE, Sokal D, McClain RM. A one-year neonatal mouse carcinogenesis study of quinacrine dihydrochloride. Int J Toxicol 2006; 25:109-18. [PMID: 16597549 DOI: 10.1080/10915810600605773] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Quinacrine is an acridine derivative under investigation for its use in nonsurgical female sterilization. Safety issues regarding the carcinogenic potential of quinacrine have been raised because it is mutagenic and clastogenic in vitro. The objective of the study was to evaluate the carcinogenic potential of quinacrine dihydrochloride (quinacrine) in neonatal mice treated with single intraperitoneal doses on postpartum days 8 and 15 and observed for 52 weeks. Neonatal Crl: CD-1 mice of each sex were randomly allocated into four treatment groups (0, 10, 50, and 150 mg/kg), dosed twice with quinacrine suspended in carboxymethylcellulose, observed for 52 weeks post dose, and then euthanized, necropsied, and subjected to a full histopathological examination. In male mice, tumor incidence was not significantly increased at any site at any dose level. In female mice, the incidence of benign uterine endometrial stromal polyps was slightly greater at the mid and high dose (> or = 50 mg/kg), as was the incidence of endometrial hyperplasia. The incidence of polyps in these groups was not significantly greater than in controls by pair-wise comparison but was significantly greater (p = .042) by the linear trend test. The authors conclude that quinacrine administered twice to neonatal mice may have enhanced or accelerated the development of endometrial hyperplasia and uterine stromal polyps at higher doses. Because uterine stromal polyps are a commonly observed benign tumor in older mice, the significance of this finding is unclear and will require a weight of evidence evaluation for a conclusion on the carcinogenic potential of quinacrine.
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Affiliation(s)
- Aida M Cancel
- Family Health International, Research Triangle Park, North Carolina, USA.
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Knight A, Bailey J, Balcombe J. Animal carcinogenicity studies: 2. Obstacles to extrapolation of data to humans. Altern Lab Anim 2006; 34:29-38. [PMID: 16522148 DOI: 10.1177/026119290603400118] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Due to limited human exposure data, risk classification and the consequent regulation of exposure to potential carcinogens has conventionally relied mainly upon animal tests. However, several investigations have revealed animal carcinogenicity data to be lacking in human predictivity. To investigate the reasons for this, we surveyed 160 chemicals possessing animal but not human exposure data within the US Environmental Protection Agency chemicals database, but which had received human carcinogenicity assessments by 1 January 2004. We discovered the use of a wide variety of species, with rodents predominating, and of a wide variety of routes of administration, and that there were effects on a particularly wide variety of organ systems. The likely causes of the poor human predictivity of rodent carcinogenicity bioassays include: 1) the profound discordance of bioassay results between rodent species, strains and genders, and further, between rodents and human beings; 2) the variable, yet substantial, stresses caused by handling and restraint, and the stressful routes of administration common to carcinogenicity bioassays, and their effects on hormonal regulation, immune status and predisposition to carcinogenesis; 3) differences in rates of absorption and transport mechanisms between test routes of administration and other important human routes of exposure; 4) the considerable variability of organ systems in response to carcinogenic insults, both between and within species; and 5) the predisposition of chronic high dose bioassays toward false positive results, due to the overwhelming of physiological defences, and the unnatural elevation of cell division rates during ad libitum feeding studies. Such factors render profoundly difficult any attempts to accurately extrapolate human carcinogenic hazards from animal data.
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Affiliation(s)
- Andrew Knight
- Animal Consultants International, London SE11 4NR, UK.
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Ennever FK, Lave LB. Implications of the lack of accuracy of the lifetime rodent bioassay for predicting human carcinogenicity. Regul Toxicol Pharmacol 2003; 38:52-7. [PMID: 12878054 DOI: 10.1016/s0273-2300(03)00068-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The NTP lifetime rodent bioassay (LRB) is the "gold standard" for predicting human carcinogenicity. Unfortunately, little attempt has been made to validate it against human carcinogenicity. Here we show that the extremely limited data available do not support either of the two common interpretations of LRB results. If a risk-avoidance interpretation is used where any positive result in a sex/species combination is considered positive, 9 of the 10 known human carcinogens tested are positive, but an implausible 22% of all chemicals are positive. If a less risk averse interpretation is used where only chemicals positive in both rats and mice are considered positive, only 3 of the 6 known human carcinogens tested are positive. In either interpretation, some known human carcinogens are not positive in the LRB, potentially allowing widespread human exposure to misidentified chemicals. Improving the predictive accuracy of the LRB and other tests for human carcinogenicity requires that test results be validated against the known human carcinogenicity of chemicals. This will require redirecting available resources from screening chemicals to validating carcinogenicity tests as well as a substantial investment in epidemiology to identify more known human carcinogens and presumed human non-carcinogens.
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Affiliation(s)
- Fanny K Ennever
- Graduate School of Industrial Administration, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
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