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Minami K, Sato A, Tomiyama N, Ogata K, Kosaka T, Hojo H, Takahashi N, Suto H, Aoyama H, Yamada T. Prenatal test cohort of a modified rat comparative thyroid assay adding brain thyroid hormone measurements and histology but lowering group size appears able to detect disruption by sodium phenobarbital. Curr Res Toxicol 2024; 6:100168. [PMID: 38693933 PMCID: PMC11061706 DOI: 10.1016/j.crtox.2024.100168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/04/2024] [Accepted: 04/16/2024] [Indexed: 05/03/2024] Open
Abstract
The Comparative Thyroid Assay (CTA, USEPA) is a screening test for thyroid hormone (TH) disruption in peripheral blood of dams and offspring. Recently, we began investigating feasible improvements to the CTA by adding examination of offspring brain TH concentrations and brain histopathology. In addition, we hypothesize that the number of animals required could be reduced by 50 % while still maintaining sensitivity to characterize treatment related changes in THs. Previously, we showed that the prenatal test cohort of the modified CTA could detect 1000 ppm sodium phenobarbital (NaPB)-induced suppression of brain T3 (by 9 %) and T4 (by 33 %) with no significant changes in serum T3 and T4 (less than 8 %). In the current study we expanded the dose response in a prenatal test cohort. Pregnant SD rats (N = 10/group) were exposed to 0, 1000 or 1500 ppm NaPB in the diet from gestational days (GD) 6 to GD20. Serum THs concentrations in GD20 dams together with serum/brain THs concentrations and brain histopathology in the GD20 fetuses were examined. NaPB dose-dependently suppressed serum T3 (up to -26 %) and T4 (up to -44 %) in dams, with suppression of T3 in serum (up to -26 %) and brain (up to -18 %) and T4 in serum (up to -26 %) and brain (up to -29 %) of fetuses but without clear dose dependency. There were no remarkable findings that deviated significantly from controls in GD20 fetal brain by qualitative histopathology. Overall, the present study suggests that the prenatal test cohort of this modified CTA is able to detect the expected fetal TH disruptions by prenatal exposure to NaPB, while also reducing the number of animals used by 50 %, consistent with the results of our previous study. These findings add to the suggestion that lowering group sizes and adding endpoints may be a useful alternative to the original CTA design.
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Affiliation(s)
- Kenta Minami
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka 554-8558, Japan
| | - Akira Sato
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Naruto Tomiyama
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Keiko Ogata
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka 554-8558, Japan
| | - Tadashi Kosaka
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Hitoshi Hojo
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Naofumi Takahashi
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Hidenori Suto
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka 554-8558, Japan
| | - Hiroaki Aoyama
- The Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
| | - Tomoya Yamada
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka 554-8558, Japan
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Minami K, Suto H, Sato A, Ogata K, Kosaka T, Hojo H, Takahashi N, Tomiyama N, Fukuda T, Iwashita K, Aoyama H, Yamada T. Feasibility study for a downsized comparative thyroid assay with measurement of brain thyroid hormones and histopathology in rats: Case study with 6-propylthiouracil and sodium phenobarbital at high dose. Regul Toxicol Pharmacol 2022; 137:105283. [PMID: 36372265 DOI: 10.1016/j.yrtph.2022.105283] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 10/12/2022] [Accepted: 10/29/2022] [Indexed: 11/13/2022]
Abstract
Concern has been raised that thyroid hormone disruptors (THDs) may potentially interfere with the developing brain, but effects of mild suppression of maternal THs by environmental contaminants on neonatal brain development are not fully understood. The comparative thyroid assay (CTA) is a screening test for offspring THDs, but it requires several animals and is criticized that reliance on serum THs alone as predictive markers of brain malfunction is inadequate. To verify feasibility of the downsized CTA but additional examination of brain THs levels and histopathology, we commenced internal-validation studies. This paper presents the data of the study where 6-propylthiouracil (6-PTU, 10 ppm) and sodium phenobarbital (NaPB, 1000 ppm) were dosed by feeding from gestational days (GD)6-20, and from GD6 to lactation day 21. The modified CTA detected 6-PTU-induced severe (>70%) suppression of serum THs in dams, with >50% suppressed serum/brain TH levels in offspring and brain heterotopia in postnatal day 21 pups. The modified CTA also detected NaPB-induced mild (<35%) suppression of serum THs in dams, with mild (<35%) reduction of serum/brain TH levels in fetuses but not in pups. These findings suggest that the modified CTA may have a potential as a screening test for offspring THDs.
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Affiliation(s)
- Kenta Minami
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka, 554-8558, Japan
| | - Hidenori Suto
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka, 554-8558, Japan
| | - Akira Sato
- Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki, 303-0043, Japan
| | - Keiko Ogata
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka, 554-8558, Japan
| | - Tadashi Kosaka
- Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki, 303-0043, Japan
| | - Hitoshi Hojo
- Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki, 303-0043, Japan
| | - Naofumi Takahashi
- Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki, 303-0043, Japan
| | - Naruto Tomiyama
- Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki, 303-0043, Japan
| | - Takako Fukuda
- Bioscience Research Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98 Kasugade-naka, Konohana-ku, Osaka, 554-8558, Japan
| | - Katsumasa Iwashita
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka, 554-8558, Japan
| | - Hiroaki Aoyama
- Institute of Environmental Toxicology, 4321, Uchimoriya-machi, Joso-shi, Ibaraki, 303-0043, Japan
| | - Tomoya Yamada
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., 3-1-98, Kasugade-naka 3-chome, Konohana-ku, Osaka, 554-8558, Japan.
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Kuwagata M, Senuma M, Todoroki M, Kumagai F, Kumamoto T, Ogawa T. Induction of a thoracolumbar supernumerary rib in rat developmental toxicity studies: A short discussion on the critical window. Congenit Anom (Kyoto) 2019; 59:190-192. [PMID: 30499140 DOI: 10.1111/cga.12320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/18/2018] [Accepted: 11/21/2018] [Indexed: 01/24/2023]
Abstract
Thoracolumbar supernumerary ribs (TSRs) are classified as less severe skeletal anomalies in rat developmental toxicity studies, although their incidence is relatively high in rodent studies. To investigate the characteristics of the critical window for chemically-induced TSR, in this study, rats were administered 5-fluorocytocine (5-FC) or sodium salicylate (SAL) at one of three time periods on gestational day (GD) 9, early morning (7:00 am), midday (12:00 pm to 1:00 pm), or late afternoon (4:00 pm or 7:00 pm). The incidence of TSR and other anomalies were assessed in GD20 fetuses. A single treatment with both chemicals on GD9-induced TSR, with the incidence highest when administered at 7:00 Am, decreasing gradually when administered later. This trajectory was clearer in rats treated with 5-FC than with SAL. The critical period of TSR induction is shorter in rats administered 5-FC than SAL. The characteristics of the critical window may cause variability in the incidence of TSR observed in developmental toxicity studies.
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Affiliation(s)
- Makiko Kuwagata
- Laboratory of Safety Evaluation, Division of Safety, Hatano Research Institute, Food and Drug Safety Center, Hadano, Japan
| | - Mika Senuma
- Laboratory of Safety Evaluation, Division of Safety, Hatano Research Institute, Food and Drug Safety Center, Hadano, Japan
| | - Mai Todoroki
- Laboratory of Safety Evaluation, Division of Safety, Hatano Research Institute, Food and Drug Safety Center, Hadano, Japan
| | - Fumiaki Kumagai
- Laboratory of Safety Evaluation, Division of Safety, Hatano Research Institute, Food and Drug Safety Center, Hadano, Japan
| | | | - Tetsuo Ogawa
- Faculty of Medicine, Saitama Medical University, Saitama, Japan
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Kuwagata M, Sakai Y, Tanaka S, Takashima H, Katagiri R, Matsuoka T, Noritake K, Senuma M, Shimizu T, Hojo H, Ibi K, Kudo S, Oota T, Ube M, Miwa Y, Kajita S, Uesugi T, Yabe K, Tateishi T, Nakano N, Taniguchi T, Yamashita A, Hirano T, Kirihata Y, Sakai Y, Nishizawa S, Fujiwara M, Mineshima H, Horimoto M, Ema M. Historical control data on developmental toxicity studies in rats. Congenit Anom (Kyoto) 2019; 59:125-131. [PMID: 30084506 DOI: 10.1111/cga.12305] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/08/2018] [Accepted: 07/29/2018] [Indexed: 11/29/2022]
Abstract
Historical control data from prenatal developmental toxicity studies in rats have been used to evaluate whether toxicology outcomes were induced by exposure to a chemical or were within the range of spontaneous variation. These data are also important for monitoring animal characteristics. As a follow-up to historical control data from 1998 to 2010, this study analyzed control data from prenatal developmental studies performed in rats from 2011 to 2015. Data were collected from studies performed by 24 Japanese laboratories, including 15 pharmaceutical and chemical companies and nine contract research organizations, in Sprague-Dawley and two-sub-strains of Wistar Hannover rats. The data included maternal reproductive findings at terminal cesarean section and fetal findings, including incidences of spontaneous external, visceral, and skeletal anomalies. No noticeable differences in maternal reproductive data were observed among laboratories. The inter-laboratory variations in the incidences of fetal anomalies seemed to be due to differences in the selection of observation parameters, observation criteria, and classification of the findings, as well as to differences in terminology of fetal alterations. These historical control data may be helpful for adequate interpretation of experimental results and for evaluating the reproductive and developmental toxicities of various chemicals.
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Affiliation(s)
- Makiko Kuwagata
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Yuko Sakai
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Sho Tanaka
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | | | - Ryuichi Katagiri
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Toshiki Matsuoka
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Kenichi Noritake
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Mika Senuma
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Tatsuya Shimizu
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Hitoshi Hojo
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Kanata Ibi
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Satoshi Kudo
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Takafumi Oota
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Masayuki Ube
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Yoji Miwa
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Shimpei Kajita
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Tohru Uesugi
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Kaoru Yabe
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Taishi Tateishi
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Nao Nakano
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | | | - Akihito Yamashita
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Takayuki Hirano
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Yuka Kirihata
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Yumi Sakai
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Shino Nishizawa
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Michio Fujiwara
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Hiroshi Mineshima
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Masao Horimoto
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
| | - Makoto Ema
- Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan
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Ema M, Endoh K, Fukushima R, Fujii S, Hara H, Hirata-Koizumi M, Hirose A, Hojo H, Horimoto M, Hoshino N, Hosokawa Y, Imai Y, Inada H, Inawaka K, Itoh K, Katsumata Y, Izumi H, Kato H, Maeda M, Matsumoto K, Matsuo S, Matsuoka T, Matsuura I, Mineshima H, Miwa Y, Nakano N, Naya M, Noyori H, Ohta T, Oku H, Ono A, Shimizu T, Shimomura K, Takakura I, Tanaka R, Tateishi T, Tominaga Y, Uesugi T, Urakawa C, Yabe K, Yamashita A, Yamauchi T, Yokoi R. Historical control data on developmental toxicity studies in rodents. Congenit Anom (Kyoto) 2014; 54:150-61. [PMID: 24666250 DOI: 10.1111/cga.12050] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 12/25/2013] [Indexed: 11/28/2022]
Abstract
Historical control data on rodent developmental toxicity studies, performed between 1994 and 2010, were obtained from 19 laboratories in Japan, including 10 pharmaceutical and chemical companies and nine contract research organizations. Rats, mice, and hamsters were used for developmental toxicity studies. Data included maternal reproductive findings at terminal cesarean sections and fetal findings including the spontaneous incidences of external, visceral, and skeletal anomalies. No noticeable differences were observed in maternal reproductive data between laboratories. Inter-laboratory variations in the incidences of fetuses with anomalies appeared to be due to differences in the selection of observation parameters, observation criteria, classification of the findings, and terminology of fetal alterations. Historical control data are useful for the appropriate interpretation of experimental results and evaluation of the effects of chemical on reproductive and developmental toxicities.
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Affiliation(s)
- Makoto Ema
- A Study Group for Historical Control Data on Prenatal Developmental Toxicity Studies in Rodents
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Tyshko N, Zhminchenko V, Selyaskin K, Pashorina V, Utembaeva N, Tutelyan V. Assessment of the impact of genetically modified LibertyLink ® maize on reproductive function and progeny development of Wistar rats in three generations. Toxicol Rep 2014; 1:330-340. [PMID: 28962249 PMCID: PMC5598231 DOI: 10.1016/j.toxrep.2014.05.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/21/2014] [Accepted: 05/21/2014] [Indexed: 11/18/2022] Open
Abstract
This publication presents the assessment of the impact of genetically modified (GM) LibertyLink® maize on reproductive function, prenatal and postnatal progeny development of Wistar rats over three generations. The animals were divided into two groups, which were fed with rodent diet with inclusion of GM LibertyLink® ('test' group) and non-GM near-isogenic counterpart ('control' group) maize varieties. The maize was included into the diet at maximum possible level (between 32 and 33%) not causing nutritional imbalance or metabolic disturbance for the experimental animals. Data analysis showed no impact of LibertyLink® maize on the animals' fertility: the observed mating efficiency in both groups was within the normal expected range values under the given experiment conditions. The comparison of progeny prenatal development in the generations F0-F2 has not shown any differences between the groups. Analysis of the physical development of the F0-F2 progeny or pups body weight and length progress did not show any abnormalities. The average number of pups per litter in the control and test groups was within the expected range of variations. Therefore, the results should be considered as direct evidence of the lack of any reproductive toxicity of LibertyLink® maize (a.k.a. T25 maize).
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Affiliation(s)
- N.V. Tyshko
- FSBI “Institute of Nutrition” RAMS, Moscow, Russian Federation
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Sato A, Abe K, Yuzuriha M, Fujii S, Takahashi N, Hojo H, Teramoto S, Aoyama H. A novel mutation in the thyroglobulin gene that causes goiter and dwarfism in Wistar Hannover GALAS rats. Mutat Res 2014; 762:17-23. [PMID: 24582622 DOI: 10.1016/j.mrfmmm.2014.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/23/2014] [Accepted: 02/18/2014] [Indexed: 06/03/2023]
Abstract
Outbred stocks of rats have been used extensively in biomedical, pharmaceutical and/or toxicological studies as a model of genetically heterogeneous human populations. One of such stocks is the Wistar Hannover GALAS rat. However, the colony of Wistar Hannover GALAS rat has been suspected of keeping a problematic mutation that manifests two distinct spontaneous abnormalities, goiter and dwarfism, which often confuses study results. We have successfully identified the responsible mutation, a guanine to thymine transversion at the acceptor site (3' end) of intron 6 in the thyroglobulin (Tg) gene (Tgc.749-1G>T), that induces a complete missing of exon 7 from the whole Tg transcript by mating experiments and subsequent molecular analyses. The following observations confirmed that Tgc.749-1G>T/Tgc.749-1G>T homozygotes manifested both dwarfism and goiter, while Tgc.749-1G>T/+ heterozygotes had only a goiter with normal appearance, suggesting that the mutant phenotypes inherit as an autosomal semi-dominant trait. The mutant phenotypes, goiter and dwarfism, mimicked those caused by typical endocrine disrupters attacking the thyroid. Hence a simple and reliable diagnostic methodology has been developed for genomic DNA-based genotyping of animals. The diagnostic methodology reported here would allow users of Wistar Hannover GALAS rats to evaluate their study results precisely by carefully interpreting the data obtained from Tgc.749-1G>T/+ heterozygotes having externally undetectable thyroidal lesions.
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Affiliation(s)
- Akira Sato
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan
| | - Kuniya Abe
- Technology and Development Team for Mammalian Genome Dynamism, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | - Misako Yuzuriha
- Technology and Development Team for Mammalian Genome Dynamism, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | - Sakiko Fujii
- Safety Research Division, Safety Research Institute for Chemical Compounds Co., Ltd., 363-24 Shin-ei, Kiyota-ku, Sapporo, Hokkaido 004-0839, Japan
| | - Naofumi Takahashi
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan
| | - Hitoshi Hojo
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan
| | - Shoji Teramoto
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan
| | - Hiroaki Aoyama
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan.
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Furukawa S, Hayashi S, Abe M, Hagio S, Irie K, Kuroda Y, Ogawa I, Sugiyama A. Background data on developmental parameters during the gestation period in rats. J Toxicol Pathol 2013; 26:83-8. [PMID: 23723574 PMCID: PMC3620220 DOI: 10.1293/tox.26.83] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Accepted: 12/17/2012] [Indexed: 12/15/2022] Open
Abstract
Abstract: Background data during the gestation period were obtained from 128 Wistar Hannover GALAS rats and 26 Crl:CD(SD) pregnant rats in the control groups of our previous toxicity studies. The body weights of dams in the Wistar Hannover GALAS rats were significantly lower throughout the gestation period than those in the Crl:CD(SD) rats. In contrast, the time-dependent change in the body weight gain (%) of dams showed very similar trends in both strains. The mean number of live embryos/fetuses in the Wistar Hannover GALAS rats was 12.0, and was lower than that (14.5) in the Crl:CD(SD) rats. The placental weights gradually increased with pregnancy progression and reached a plateau on gestation day (GD) 19, although the embryo/fetal weights rapidly increased from GD 17 to GD 21. The embryo/fetal weights in the Wistar Hannover GALAS rats were significantly lower on only GD 21 than those in the Crl:CD(SD) rats. It is considered that this fetal weight difference between the strains develops during the fetal period, but not during the organogenesis period. In contrast, there were no differences in the placental weights between the two strains. Microscopically, the thickness of the labyrinth zone in the Wistar Hannover GALAS rats was thicker throughout the gestation period than that in the Crl:CD(SD) rats.
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Affiliation(s)
- Satoshi Furukawa
- Biological Research Laboratories, Nissan Chemical Industries, Ltd., 1470 Shiraoka, Shiraoka, Saitama 349-0294, Japan
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Noritake KI, Ikeda T, Ito K, Miwa Y, Senuma M, Takashima H, Tateishi T, Hisada S, Maki E. A Study for collecting background data on Wistar Hannover [Crl:WI(Han)] rats in embryo-fetal development studies - comparative data to Sprague Dawley rats -. J Toxicol Sci 2013; 38:847-54. [DOI: 10.2131/jts.38.847] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Ken-ichi Noritake
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., Present address; Preclinical Safety Research Laboratories, Sunplanet Co., Ltd
| | - Takashi Ikeda
- Safety Research Department, ASKA Pharmaceutical Co., Ltd
| | - Keiichi Ito
- Biosafety Research Center, Foods, Drugs and Pesticides
| | | | - Mika Senuma
- Hatano Research Institute, Food and Drug Safety Center
| | | | | | - Shigeru Hisada
- Safety Research Department, ASKA Pharmaceutical Co., Ltd
| | - Eiji Maki
- Consultant on Drug Safety Assessment
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10
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Gotoh H, Aoyama H. Spermatogenic defects in F2 mice between normal mouse strains C3H and C57BL/6 without mutation. Congenit Anom (Kyoto) 2012. [PMID: 23181493 DOI: 10.1111/j.1741-4520.2012.00379.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Genetic disorders are usually considered to be caused by harmful gene mutations, as well as by chromosomal aberrations, including small insertions, duplications and/or deletions. However, as infertile individuals often arise among the offspring of crosses between two fertile mouse strains, we postulate that a certain combination of 'normal' genes with neither gene mutations nor chromosomal aberrations can cause such serious phenotypic alterations as reproductive dysfunction. In this study, we show evidence that a combination of multiple normal genes from two different normal mouse strains manifests a wide range of male reproductive dysfunctions, from benign changes to complete infertility. These abnormal phenotypes are thought to have occurred by epistatic interactions of alleles.
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Affiliation(s)
- Hideo Gotoh
- Agrogenomics Research Center, National Institute of Agrobiological Sciences, Tsukuba.
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Aoyama H, Hojo H, Takahashi KL, Shimizu-Endo N, Araki M, Takeuchi-Kashimoto Y, Saka M, Teramoto S. Two-generation reproduction toxicity study in rats with methoxychlor. Congenit Anom (Kyoto) 2012; 52:28-41. [PMID: 22348781 DOI: 10.1111/j.1741-4520.2011.00344.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A two-generation reproduction toxicity study was conducted in rats with a reference estrogenic pesticide, methoxychlor, to validate the sensitivity and competency of current guidelines recommended by the United States Environmental Protection Agency; Japanese Ministry of Agriculture, Forestry and Fisheries; and Organisation for Economic Co-operation and Development for predicting reproductive toxicity of the test compound based on estrogenic endocrine disrupting effects. Both sexes of SD rats were exposed to methoxychlor in the diet at concentrations of 0, 10, 500 and 1500 ppm for two successive generations. The present study has successfully detected estrogenic activities and reproductive toxicities of methoxychlor, as well as its systemic toxicity. Body weights, body weight gains and food consumption of both sexes of animals were suppressed significantly in the 500 and 1500 ppm groups. Typical reproductive toxicities observed in females of these groups included, but were not limited to, prolonged estrous cycle, reduced fertility, decreased numbers of implantation sites and newborns, decreased ovary weights and/or increased incidences of cystic ovary. Uterine weights of weanlings increased significantly in these groups, suggesting that the sensitivity of this parameter for predicting estrogenic ability of the test compound is comparable to that of the uterotrophic assay. Reproductive toxicities of methoxychlor seemed less potent in males than in females. Methoxychlor delayed preputial separation and significantly reduced sperm counts and reproductive organ weights of males of the 500 and/or 1500 ppm groups; however, most males that failed to impregnate females in the same group showed normal fertility when they were re-mated with untreated females. Neither systemic nor reproductive toxicities appeared in the 10 ppm group.
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Affiliation(s)
- Hiroaki Aoyama
- Laboratories of Reproductive Toxicology, Toxicology Division, Institute of Environmental Toxicology, Ibaraki, Japan.
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Takeuchi T, Okuda H, Kasahara Y, Ushigome S, Aihara I, Fukushima S. Differences in spontaneous fetal abnormalities among three outbred stocks of Wistar Hannover rats in Japan. Congenit Anom (Kyoto) 2011; 51:149-52. [PMID: 21848998 DOI: 10.1111/j.1741-4520.2010.00305.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Wistar Hannover rats, which are maintained by three animal breeders in Japan, were examined to obtain basic data on reproductive and developmental parameters. Untreated pregnant females were terminated on gestational day 20, and the fetuses were removed by cesarian section. The fetuses were counted, weighed and examined for morphological abnormalities. There were few differences among the three stocks of Wistar Hannover rats on the numbers of implantations and live fetuses, sex ratio and fetal weights. The most common fetal abnormalities were the presence of left-sided umbilical arteries, supernumerary ribs and wavy ribs. The incidences of these abnormalities were different among the three stocks of Wistar Hannover rats. Our results provide important data which should be considered in the determination of which stock of rat is used in developmental studies.
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Affiliation(s)
- Tetsuya Takeuchi
- Japan Bioassay Research Center, Japan Industrial Safety and Health Association, Kanagawa.
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van Drongelen J, Pertijs J, Wouterse A, Hermsen R, Sweep FC, Lotgering FK, Smits P, Spaanderman ME. Contribution of different local vascular responses to mid-gestational vasodilation. Am J Obstet Gynecol 2011; 205:155.e12-7. [PMID: 21529754 DOI: 10.1016/j.ajog.2011.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 02/22/2011] [Accepted: 03/08/2011] [Indexed: 10/18/2022]
Abstract
OBJECTIVE At-term pregnancy-induced vasodilation is the resultant of endothelium-dependent vasodilation, decreased myogenic reactivity, increased compliance, and reduced sensitivity to vasoconstrictor agents. We hypothesized that these vascular changes are already present at mid-gestation. STUDY DESIGN In 20 mid-pregnant and 20 nonpregnant Wistar Hannover rats, we measured vascular responses of isolated mesenteric arteries and kidney. RESULTS In the pregnant rats compared with the nonpregnant rats, mesenteric flow-mediated vasodilation and renal perfusion flow increased 1.52-fold (from 47±5 to 31±4 μL/min) and 1.13-fold (from 12.8±0.1 to 14.4±0.1 mL/min), respectively. Nitric oxide inhibition reduced mesenteric flow-mediated vasodilation to a similar extent in the pregnant and nonpregnant rats; it completely blocked the pregnancy-induced increase in renal perfusion flow. Pregnancy did not change mesenteric artery sensitivity to phenylephrine, myogenic reactivity, nor vascular compliance. CONCLUSION At mid-gestation, alterations in rat mesenteric vascular tone depend primarily on flow-mediated endothelium-dependent changes and not on changes in α-adrenergic vasoconstrictor sensitivity, myogenic reactivity, or vascular compliance.
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Teratogenicity and maternal effects of Lactobacillus brevis KB290 in rats and rabbits. Food Chem Toxicol 2010; 49:722-6. [PMID: 21112368 DOI: 10.1016/j.fct.2010.11.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 10/18/2010] [Accepted: 11/20/2010] [Indexed: 12/11/2022]
Abstract
Lactobacillus brevis KB290 (KB290), a plant-derived probiotic lactic acid bacterium, improves gut health and stimulates immune function. Here we extensively investigated the teratogenicity of KB290 in rats and rabbits. We observed no adverse maternal or fetal effects and concluded that the no observable adverse effect level for maternal general toxicity, maintenance of pregnancy, and teratogenicity should be ≥ 10(10) cfu/kg/day. Our results suggest that KB290 would be safe for pregnant females and their offspring.
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Weyrauch UM, Torres EM, Baird AL, Dunnett SB. A Simple Breeding Protocol for the Procurement of Accurately Staged Rat Donor Embryos for Neural Transplantation. Cell Transplant 2009; 18:471-6. [DOI: 10.3727/096368909788809802] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Obtaining accurately staged rat embryos can be difficult because of the variety of breeding protocols employed and because precise staging cannot be confirmed until excision of the embryos from the dam. The detection of estrus, pairing of animals, and confirmation of pregnancies is generally left to commercial suppliers, as in-house breeding can be laborious and unpredictable. Here we describe a simple, reliable in-house breeding protocol for the generation of accurately staged embryos as assessed by measurements of average crown to rump length (CRL).
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Affiliation(s)
- U. M. Weyrauch
- Department of Biosciences, Cardiff University, Cardiff, UK
| | - E. M. Torres
- Department of Biosciences, Cardiff University, Cardiff, UK
| | - A. L. Baird
- Department of Biosciences, Cardiff University, Cardiff, UK
| | - S. B. Dunnett
- Department of Biosciences, Cardiff University, Cardiff, UK
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Kishida T, Muto SI, Hayashi M, Tsutsui M, Tanaka S, Murakami M, Kuroda J. Strain differences in hepatic cytochrome P450 1A and 3A expression between Sprague-Dawley and Wistar rats. J Toxicol Sci 2008; 33:447-57. [DOI: 10.2131/jts.33.447] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Tomoyuki Kishida
- Toxicology Research Laboratory, R & D, Kissei Pharmaceutical Co., Ltd
| | - Shin-ichi Muto
- Toxicology Research Laboratory, R & D, Kissei Pharmaceutical Co., Ltd
| | - Morimichi Hayashi
- Toxicology Research Laboratory, R & D, Kissei Pharmaceutical Co., Ltd
| | - Masaru Tsutsui
- Toxicology Research Laboratory, R & D, Kissei Pharmaceutical Co., Ltd
| | - Satoru Tanaka
- Toxicology Research Laboratory, R & D, Kissei Pharmaceutical Co., Ltd
| | - Makoto Murakami
- Toxicology Research Laboratory, R & D, Kissei Pharmaceutical Co., Ltd
| | - Junji Kuroda
- Toxicology Research Laboratory, R & D, Kissei Pharmaceutical Co., Ltd
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Hojo H, Aoyama H, Takahashi KL, Shimizu N, Araki M, Takizawa Y, Sakasai K, Kuwahara M, Saka M, Teramoto S. Two-generation reproduction toxicity study in rats with 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT). Congenit Anom (Kyoto) 2006; 46:105-14. [PMID: 16732769 DOI: 10.1111/j.1741-4520.2006.00110.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DDT, an organochlorine pesticide, has been cited as a representative chemical suspected of having endocrine disrupting effects. In this study, the potential endocrine disrupting activities of p,p'-DDT, a major component of DDT, were investigated in rats in a 2-generation reproduction toxicity study in accordance with the most current test guidelines of the Ministry of Agriculture, Forestry and Fisheries in Japan, Organization for Economic Cooperation and Development (OECD) and United States Environmental Protection Agency (USEPA) with some modifications and additions. p,p'-DDT was given to parental rats at dietary levels of 0, 5, 50 or 350 ppm. Systemic toxicities in the parental animals consisted of tremors and subsequent deaths (females only) and/or pathological alterations of the liver (both sexes of animals) of the 2 higher dose groups. Reproductive and postnatal developmental toxicities were not evident up to the highest dose level except for the decreased pup viability index on postnatal day 21 in the 350 ppm group. Changes in serum estradiol and progesterone levels and/or a delay in male sexual maturation were noted in the 2 higher dose groups in a dose-dependent fashion, suggesting alterations of endogenous endocrine functions. However, these changes never resulted in substantial reproductive disorders.
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Affiliation(s)
- Hitoshi Hojo
- Laboratories of Reproductive Toxicology, Toxicology Division, Institute of Environmental Toxicology, Ibaraki, Japan
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Aoyama H, Hojo H, Takahashi KL, Shimizu N, Araki M, Harigae M, Tanaka N, Shirasaka N, Kuwahara M, Nakashima N, Yamamoto E, Saka M, Teramoto S. A TWO-GENERATION REPRODUCTIVE TOXICITY STUDY OF 2,4-DICHLOROPHENOL IN RATS. J Toxicol Sci 2005; 30 Spec No.:59-78. [PMID: 16641544 DOI: 10.2131/jts.30.s59] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A two-generation reproductive toxicity study was conducted with 2,4-dichlorophenol (2,4-DCP), an agent suspected of exerting endocrine disrupting effects. Wistar-Hannover rats, 24/sex/group, were given diet containing 2,4-DCP at dose levels of 0, 500, 2000 or 8000 ppm to examine the potential effects of the test substance on parental animals and their offspring over 2 successive generations. Neither clear systemic nor reproductive toxicity of 2,4-DCP was apparent in the 500 ppm group. In the 2000 ppm group, mean body weight gain and food consumption of females were lowered significantly during the treatment period. Effects on body weights and food consumption were more serious in the 8000 ppm group, both males and females being significantly affected. Reproductive effects of the test substance were also observed in the 2000 and 8000 ppm groups dose-dependently. Observations included significantly increased uterine weights of F1 and/or F2 female weanlings and reduced numbers of implantation sites and live births of F1 parental females. These results suggest that 2,4-DCP has weak reproductive toxicity, possibly based on endocrine activity. However, the basic mechanisms for apparent estrogenic effects of 2,4-DCP remain to be elucidated.
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Affiliation(s)
- Hiroaki Aoyama
- Laboratory of Reproductive Toxicology, Chemistry Division , Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Mitsukaido-shi, Ibaraki 303-0043, Japan.
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Ganmaa D, Qin LQ, Wang PY, Tezuka H, Teramoto S, Sato A. A two-generation reproduction study to assess the effects of cows' milk on reproductive development in male and female rats. Fertil Steril 2004; 82 Suppl 3:1106-14. [PMID: 15474082 DOI: 10.1016/j.fertnstert.2004.05.073] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2004] [Revised: 05/14/2004] [Accepted: 05/14/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To examine whether the considerable quantities of increased female sex hormone levels found in modern milk as a result of modern dairy farming practices are safe for human consumption. DESIGN Males and females of the P generation were maintained on a diet containing milk for 10 weeks before mating. Exposure to milk was continued up to the end of weaning of the F2b offspring. SETTING Two-generation reproduction study. ANIMAL(S) Male and female Wistar Galas rats. INTERVENTION(S) P- and F1-generation rats were mated. MAIN OUTCOME MEASURE(S) Fertility, fecundity, and morphology and function of reproductive organs. RESULT(S) Although milk had growth-promoting effects in both parents and offspring, it caused no impairments in fertility, fecundity, or reproductive organ development in either generation. However, a whole litter from a dam of the P generation was born dead, three litters in total had a pup with skeletal abnormalities, and the AGD of F2a female pups was reduced. These events occurred only in the milk-treated rats. It is unknown whether these issues had any relevance to milk or only happened by chance. CONCLUSION(S) Further study is required to determine whether milk from pregnant cows is completely free from adverse effects on reproductive health.
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Affiliation(s)
- Davaasambuu Ganmaa
- Department of Environmental Health, Medical University of Yamanashi, Japan
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