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Kim M, Jeong JS, Kim H, Hwang S, Park IH, Lee BC, Yoon SI, Jee SH, Nam KT, Lim KM. Low Dose Exposure to Di-2-Ethylhexylphthalate in Juvenile Rats Alters the Expression of Genes Related with Thyroid Hormone Regulation. Biomol Ther (Seoul) 2018; 26:512-519. [PMID: 30078309 PMCID: PMC6131019 DOI: 10.4062/biomolther.2018.076] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/23/2018] [Accepted: 06/26/2018] [Indexed: 11/06/2022] Open
Abstract
Phthalates widely used in the manufacture of plastics have deeply penetrated into our everyday lives. Recently, a concern over the toxicity of phthalates on thyroid, has been raised but in most of cases, the doses employed were unrealistically high. To investigate the effects of phthalates on thyroid, we investigated the effects of the repeated oral exposure to low to high doses (0.3, 3, 30 and 150 mg/kg) di-2-ethylhexylphthalate (DEHP) from weaning to maturity for 90 days in juvenile rats on the thyroid. The histological examination revealed that DEHP significantly induced hyperplasia in the thyroid from the doses of 30 mg/kg, which was confirmed with Ki67 staining. In line with this finding, increased mRNA expression of thyrotropin releasing hormone (Trh) was observed in the thyroid of female at 0.3 mg/kg and 150 mg/kg as determined by RNAseq analysis. Moreover, significantly increased expression of parathyroid hormone (Pth) in the female at 0.3 mg/kg, and thyroglobulin (Tg) and thyroid hormone responsive (Thrsp) in the male at 0.3 mg/kg were noted in the blood, of which changes were substantially attenuated at 150 m/kg, alluding the meaningful effects of low dose DEHP on the thyroid hormone regulation. Urinary excretion of mono-2-ethylhexyl-phthalate (MEHP), a major metabolite of DEHP was determined to be 4.10 and 12.26 ppb in male, 6.65 and 324 ppb in female at 0.3 and 30 mg/kg DEHP, respectively, which fell within reported human urine levels. Collectively, these results suggest a potential adverse effects of low dose phthalates on the thyroid.
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Affiliation(s)
- Minjeong Kim
- College of Pharmacy, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Ji Seong Jeong
- Developmental and Reproductive Toxicology Research Group, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Hyunji Kim
- Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Seungwoo Hwang
- Korean Bioinformation Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
| | | | | | - Sung Il Yoon
- Department of Epidemiology and Health Promotion, and Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul 03722, Republic of Korea
| | - Sun Ha Jee
- Lab frontier Co., Anyang 14042, Republic of Korea
| | - Ki Taek Nam
- Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Kyung-Min Lim
- College of Pharmacy, Ewha Womans University, Seoul 03760, Republic of Korea
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Jeong JS, Nam KT, Lee B, Pamungkas AD, Song D, Kim M, Yu WJ, Lee J, Jee S, Park YH, Lim KM. Low-Dose Bisphenol A Increases Bile Duct Proliferation in Juvenile Rats: A Possible Evidence for Risk of Liver Cancer in the Exposed Population? Biomol Ther (Seoul) 2017; 25:545-552. [PMID: 28822992 PMCID: PMC5590799 DOI: 10.4062/biomolther.2017.148] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 08/03/2017] [Accepted: 08/03/2017] [Indexed: 11/05/2022] Open
Abstract
Increasing concern is being given to the association between risk of cancer and exposure to low-dose bisphenol A (BPA), especially in young-aged population. In this study, we investigated the effects of repeated oral treatment of low to high dose BPA in juvenile Sprague-Dawley rats. Exposing juvenile rats to BPA (0, 0.5, 5, 50, and 250 mg/kg oral gavage) from post-natal day 9 for 90 days resulted in higher food intakes and increased body weights in biphasic dose-effect relationship. Male mammary glands were atrophied at high dose, which coincided with sexual pre-maturation of females. Notably, proliferative changes with altered cell foci and focal inflammation were observed around bile ducts in the liver of all BPA-dosed groups in males, which achieved statistical significance from 0.5 mg/kg (ANOVA, Dunnett's test, p<0.05). Toxicokinetic analysis revealed that systemic exposure to BPA was greater at early age (e.g., 210-fold in Cmax, and 26-fold in AUC at 50 mg/kg in male on day 1 over day 90) and in females (e.g., 4-fold in Cmax and 1.6-fold in AUC at 50 mg/kg vs. male on day 1), which might have stemmed from either age- or gender-dependent differences in metabolic capacity. These results may serve as evidence for the association between risk of cancer and exposure to low-dose BPA, especially in young children, as well as for varying toxicity of xenobiotics in different age and gender groups.
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Affiliation(s)
- Ji Seong Jeong
- Developmental and Reproductive Toxicology Research Group, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Ki Taek Nam
- Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Buhyun Lee
- Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | | | - Daeun Song
- College of Pharmacy, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Minjeong Kim
- College of Pharmacy, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Wook-Joon Yu
- Developmental and Reproductive Toxicology Research Group, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Jinsoo Lee
- Developmental and Reproductive Toxicology Research Group, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Sunha Jee
- Department of Epidemiology and Health Promotion, and Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul 03722, Republic of Korea
| | - Youngja H Park
- College of Pharmacy, Korea University, Sejong 30019, Republic of Korea
| | - Kyung-Min Lim
- College of Pharmacy, Ewha Womans University, Seoul 03760, Republic of Korea
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Cappon GD. Nonclinical support of pediatric drug development in a global context: an industry perspective. ACTA ACUST UNITED AC 2011; 92:269-72. [PMID: 21594976 DOI: 10.1002/bdrb.20303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 04/08/2011] [Indexed: 11/10/2022]
Abstract
The earlier inclusion of children into clinical trials has challenged toxicologists to develop nonclinical strategies to support these trials early in the drug development process, and the routine practise of global development strategies (i.e., concomitant development and filing in multiple geographical regions) adds another complication. Ideally, one would like to develop a stagey that would meet regulatory requirements from all regions. This presentation illustrated the challenges faced in developing a strategy regarding the need to perform a toxicity study in juvenile animals and the design of any necessary study that will receive global regulatory agreement.
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Affiliation(s)
- Gregg D Cappon
- Pfizer Global Research & Development, Groton Laboratories, Eastern Point Rd., Groton, CT 06340, USA.
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