1
|
Yuan YZ, Ye C, Sun JH, Hu MY, Huo SJ, Zhu YT, Xiang SY, Yu SQ. Toxicokinetics of mono-(2-ethylhexyl) phthalate with low-dose exposure applying fluorescence tracing technique. Toxicol Appl Pharmacol 2022; 434:115814. [PMID: 34843800 DOI: 10.1016/j.taap.2021.115814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 11/19/2022]
Abstract
Di(2-ethylhexyl) phthalate (DEHP) belongs to environmental endocrine disrupting chemicals (EEDCs) and can be rapidly hydrolyzed into the ultimate toxicant mono-2-ethylhexyl phthalate (MEHP). In this study, we used 5-aminofluorescein modified MEHP (MEHP-AF) as a fluorescence tracer to explore the toxicokinetics, including toxicokinetic parameters, absorption and transport across the intestinal mucosal barrier, distribution and pathological changes of organs. While the dose was as lower than 10 mg/kg by intragastric administration, the toxicokinetic parameters obtained by fluorescence microplate method were similar to those with the literatures by chromatography. MEHP-AF can be rapidly absorbed through the intestinal mucosal barrier in rats. In situ organ distribution in mice showed that MEHP-AF was mainly concentrated in the liver, kidney and testis. Our results suggested that the fluorescence tracing technique had the advantages with easy processing, less time-consuming, higher sensitivity for the quantitative determination, In addition, this technology also avoids the interference of exogenous or endogenous DEHP and MEHP in the experimental system. It also can be utilized to the visualization detection of MEHP in situ localization in the absorption organ and the toxic target organ. The results show that this may be a more feasible MEHP toxicological research method.
Collapse
Affiliation(s)
- Yi-Zhen Yuan
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China
| | - Chong Ye
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China
| | - Jia-Hui Sun
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China
| | - Meng-Yuan Hu
- College of Food and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210046, People's Republic of China
| | - Shao-Jie Huo
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China
| | - Yu-Ting Zhu
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China
| | - Su-Yun Xiang
- College of Food and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210046, People's Republic of China.
| | - Shu-Qin Yu
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, People's Republic of China.
| |
Collapse
|
2
|
Rajkumar A, Luu T, Beal MA, Barton-Maclaren TS, Hales BF, Robaire B. Phthalates and Alternative Plasticizers Differentially affect Phenotypic Parameters in Gonadal Somatic and Germ Cell Lines. Biol Reprod 2021; 106:613-627. [PMID: 34792101 DOI: 10.1093/biolre/ioab216] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/11/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
The developmental and reproductive toxicity associated with exposure to phthalates has motivated a search for alternatives. However, there is limited knowledge regarding the adverse effects of some of these chemicals. We used high-content imaging to compare the effects of mono (2-ethylhexyl) phthalate (MEHP) with six alternative plasticizers: di-2-ethylhexyl terephthalate (DEHTP); diisononyl-phthalate (DINP); di-isononylcyclohexane-1,2-dicarboxylate (DINCH); 2-ethylhexyl adipate (DEHA); 2,2,4-trimethyl 1,3-pentanediol diisobutyrate (TXIB) and di-iso-decyl-adipate (DIDA). A male germ spermatogonial cell line (C18-4), a Sertoli cell line (TM4) and two steroidogenic cell lines (MA-10 Leydig and KGN granulosa) were exposed for 48h to each chemical (0.001-100 μM). Cell images were analyzed to assess cytotoxicity and effects on phenotypic endpoints. Only MEHP (100 μM) was cytotoxic and only in C18-4 cells. However, several plasticizers had distinct phenotypic effects in all four cell lines. DINP increased Calcein intensity in C18-4 cells, whereas DIDA induced oxidative stress. In TM4 cells, MEHP, and DINCH affected lipid droplet numbers, while DEHTP and DINCH increased oxidative stress. In MA-10 cells, MEHP increased lipid droplet areas and oxidative stress; DINP decreased the number of lysosomes, while DINP, DEHA and DIDA altered mitochondrial activity. In KGN cells, MEHP, DINP and DINCH increased the number of lipid droplets, whereas DINP decreased the number of lysosomes, increased oxidative stress and affected mitochondria. The Toxicological Priority Index (ToxPi) provided a visual illustration of the cell line specificity of the effects on phenotypic parameters. The lowest administered equivalent doses were observed for MEHP. We propose that this approach may assist in screening alternative plasticizers.
Collapse
Affiliation(s)
- Abishankari Rajkumar
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada, H3G 1Y6
| | - Trang Luu
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada, H3G 1Y6
| | - Marc A Beal
- Existing Substances Risk Assessment Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada, KIA 0K9
| | - Tara S Barton-Maclaren
- Existing Substances Risk Assessment Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada, KIA 0K9
| | - Barbara F Hales
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada, H3G 1Y6
| | - Bernard Robaire
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada, H3G 1Y6.,Department of Obstetrics & Gynecology, McGill University, Montreal, QC, Canada. H3G 1Y6
| |
Collapse
|
3
|
Hwang DY, Cho JS, Oh JH, Shim SB, Jee SW, Lee SH, Seo SJ, Kang HG, Sheen YY, Lee SH, Kim YK. An In Vivo Bioassay for Detecting Antiandrogens Using Humanized Transgenic Mice Coexpressing the Tetracycline-Controlled Transactivator and Human CYP1B1 Gene. Int J Toxicol 2016; 24:157-64. [PMID: 16040568 DOI: 10.1080/10915810590948370] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The typical strategy used in analysis of antiandrogens involves the morphological changes of a marker in castrated rats Hershberger assay for the prostate, seminal vesicle, levator ani plus bulbocavernosus muscles (LABC), Cowper’s gland, and glans penis. However, there are disadvantages to this approach, such as the time required, and the results may not correspond to those in actual human exposure. To evaluate its ability for detecting antiandrogens, in vivo the dose effect of di-(2-ethylhexyl) phthalate (DEHP) and time effect of five antiandrogens, DEHP, di-n-butyl phthalate (DBP), diethyl phthalate (DEP), linuron (3-(4-dichlorophenyl)-methoxy-1-methylurea), and 2,4′-DDE (1,1-dichloro-2-( p-chlorophenyl)-2-( o-chlorophenyl)ethylene), were investigated using humanized transgenic mice coexpressing tetracycline-controlled transactivator (tTA) and the human cytochrome P450 (CYP) enzyme CYP1B1 (hCYP1B1). Adult transgenic males were treated with each of the five antiandrogens, and their tTA-driven hCYP1B1 expressions analyzed by real-time polymerase chain reaction (PCR) and/or Western blot and for O-debenzylation activity. Herein, the treatments of adult males with the five antiandrogens were shown to affect the increased levels of tTA-driven hCYP1B1 expression in both dose-dependent and repeated experiments. Thus, this novel in vivo bioassay, using humanized transgenic mice, is useful for measuring antiandrogens, and is a means to a more relevant bioas-say relating to actual human exposure.
Collapse
Affiliation(s)
- Dae Y Hwang
- Division of Laboratory Animal Resources, Korea Food and Drug Administration, National Institute of Toxicological Research, Eunpyng-ku, Seoul, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
|
5
|
Phthalates Are Metabolised by Primary Thyroid Cell Cultures but Have Limited Influence on Selected Thyroid Cell Functions In Vitro. PLoS One 2016; 11:e0151192. [PMID: 26985823 PMCID: PMC4795645 DOI: 10.1371/journal.pone.0151192] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/24/2016] [Indexed: 11/19/2022] Open
Abstract
Phthalates are plasticisers added to a wide variety of products, resulting in measurable exposure of humans. They are suspected to disrupt the thyroid axis as epidemiological studies suggest an influence on the peripheral thyroid hormone concentration. The mechanism is still unknown as only few in vitro studies within this area exist. The aim of the present study was to investigate the influence of three phthalate diesters (di-ethyl phthalate, di-n-butyl phthalate (DnBP), di-(2-ethylhexyl) phthalate (DEHP)) and two monoesters (mono-n-butyl phthalate and mono-(2-ethylhexyl) phthalate (MEHP)) on the differentiated function of primary human thyroid cell cultures. Also, the kinetics of phthalate metabolism were investigated. DEHP and its monoester, MEHP, both had an inhibitory influence on 3'-5'-cyclic adenosine monophosphate secretion from the cells, and MEHP also on thyroglobulin (Tg) secretion from the cells. Results of the lactate dehydrogenase-measurements indicated that the MEHP-mediated influence was caused by cell death. No influence on gene expression of thyroid specific genes (Tg, thyroid peroxidase, sodium iodine symporter and thyroid stimulating hormone receptor) by any of the investigated diesters could be demonstrated. All phthalate diesters were metabolised to the respective monoester, however with a fall in efficiency for high concentrations of the larger diesters DnBP and DEHP. In conclusion, human thyroid cells were able to metabolise phthalates but this phthalate-exposure did not appear to substantially influence selected functions of these cells.
Collapse
|
6
|
Frohnert Hansen J, Boas M, Møller Brorson M, Frederiksen H, Hartoft-Nielsen ML, Krogh Rasmussen Å, Main KM, Feldt-Rasmussen U. Migration of phthalates on culture plates - an important challenge to consider for in vitro studies. Scandinavian Journal of Clinical and Laboratory Investigation 2016; 76:165-71. [PMID: 26754760 DOI: 10.3109/00365513.2015.1110857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Phthalates are endocrine disruptors of the reproductive system and suspected to influence many other organ and hormone systems. They are also semi-volatile organic compounds present in the gas phase in the environment. Their mode of action has been investigated in numerous in vitro studies. Multi-well culture plates are typically used to study phthalates in cell cultures. In a pilot study, we observed evidence of phthalate migration in 24-well culture plates. As this has not previously been described, we investigated the phenomenon in more detail. Primary human thyroid epithelial cell cultures (n = 8 cultures) were exposed to either di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), mono-n-butyl phthalate (MnBP) or di-(2-ethylhexyl) phthalate (DEHP). Measurement of phthalate metabolites by mass spectrometry demonstrated that the short-branched DEP was able to migrate to adjacent wells when added to cell culture plates. DnBP also seemed to be able to migrate, unlike the long-branched DEHP or the monoester MnBP which did not seem to have this ability. High background levels of phthalate metabolites were also observed, which might compromise results from low dose phthalate studies. In conclusion, the migration of phthalates which is probably caused by their volatile properties might lead to false interpretation of study results.
Collapse
Affiliation(s)
| | - Malene Boas
- b Department of Growth and Reproduction , Rigshospitalet, University of Copenhagen , Denmark
| | | | - Hanne Frederiksen
- b Department of Growth and Reproduction , Rigshospitalet, University of Copenhagen , Denmark
| | | | - Åse Krogh Rasmussen
- a Department of Medical Endocrinology , Rigshospitalet, University of Copenhagen , Denmark
| | - Katharina M Main
- b Department of Growth and Reproduction , Rigshospitalet, University of Copenhagen , Denmark
| | - Ulla Feldt-Rasmussen
- a Department of Medical Endocrinology , Rigshospitalet, University of Copenhagen , Denmark
| |
Collapse
|
7
|
Savchuk I, Söder O, Svechnikov K. Mono-2-ethylhexyl phthalate stimulates androgen production but suppresses mitochondrial function in mouse leydig cells with different steroidogenic potential. Toxicol Sci 2015; 145:149-56. [PMID: 25677926 DOI: 10.1093/toxsci/kfv042] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Numerous studies have reported on testicular toxicity of phthalates in different experimental paradigms and showed that Leydig cells (LCs) were one of the main targets of phthalate actions. Adverse effects of phthalates on LCs steroidogenesis have been attributed to their metabolites, monophthalates. This study focuses on investigation whether LCs responsiveness to monophthalates action is associated with their potential to produce androgens. We found that of 3 monophthalates investigated [ie, mono-2-ethylhexyl phthalate (MEHP), mono-n-butyl phthalate, and mono-n-benzyl phthalate] only MEHP caused biological effects on the mouse LCs function. This monophthalate stimulated basal steroidogenesis associated with upregulation of StAR protein expression with no effect on hCG-stimulated androgen production by LCs from CBA/Lac and C57BL/6j mouse genotypes were observed. Further, MEHP attenuated ATP production and increased superoxide generation by both phenotypes of mouse LCs that indicated on mitochondrial dysfunction induced by the monophthalate. All together, our data indicate that MEHP-mediated stimulation of steroidogenesis and perturbation in mitochondrial function are not associated with the capacity of the LCs to synthesize androgens. We suggest that this effect of MEHP observed in LCs of rodent origin needs to be taken into consideration in analysis of earlier start of puberty in boys and may highlight a possible influence of phthalates on reproductive health in males.
Collapse
Affiliation(s)
- Iuliia Savchuk
- Department of Woman and Child Health, Pediatric Endocrinology Unit Q2:08, Karolinska Institute and University Hospital, Astrid Lindgren Children's Hospital, SE-17176 Stockholm, Sweden
| | - Olle Söder
- Department of Woman and Child Health, Pediatric Endocrinology Unit Q2:08, Karolinska Institute and University Hospital, Astrid Lindgren Children's Hospital, SE-17176 Stockholm, Sweden
| | - Konstantin Svechnikov
- Department of Woman and Child Health, Pediatric Endocrinology Unit Q2:08, Karolinska Institute and University Hospital, Astrid Lindgren Children's Hospital, SE-17176 Stockholm, Sweden
| |
Collapse
|
8
|
Bradley EL, Burden RA, Bentayeb K, Driffield M, Harmer N, Mortimer DN, Speck DR, Ticha J, Castle L. Exposure to phthalic acid, phthalate diesters and phthalate monoesters from foodstuffs: UK total diet study results. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2013; 30:735-42. [DOI: 10.1080/19440049.2013.781684] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
9
|
Breslin WJ, Paulman A, Sun-Lin D, Goldstein KM, Derr A. The Inhibin B (InhB) Response to the Testicular Toxicants Mono-2-Ethylhexyl Phthalate (MEHP), 1,3 Dinitrobenzene (DNB), or Carbendazim (CBZ) Following Short-term Repeat Dosing in the Male Rat. ACTA ACUST UNITED AC 2013; 98:72-81. [DOI: 10.1002/bdrb.21043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 12/12/2012] [Indexed: 11/10/2022]
Affiliation(s)
- William J. Breslin
- Non-Clinical Safety Assessment, Lilly Research Laboratories; Lilly Corporate Center; Indianapolis; Indiana
| | - April Paulman
- Department of Pathology; Covance Laboratories Inc; Greenfield; Indiana
| | - Denise Sun-Lin
- Investigative Toxicology, Lilly Research Laboratories; Lilly Corporate Center; Indianapolis; Indiana
| | - Keith M. Goldstein
- Investigative Toxicology, Lilly Research Laboratories; Lilly Corporate Center; Indianapolis; Indiana
| | - Angela Derr
- Discovery and Translational Services; Covance Laboratories Inc; Greenfield; Indiana
| |
Collapse
|
10
|
Yuan K, Zhao B, Li XW, Hu GX, Su Y, Chu Y, Akingbemi BT, Lian QQ, Ge RS. Effects of phthalates on 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase 3 activities in human and rat testes. Chem Biol Interact 2012; 195:180-8. [DOI: 10.1016/j.cbi.2011.12.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 10/14/2022]
|
11
|
Takatori S, Akutsu K, Kondo F, Ishii R, Nakazawa H, Makino T. Di(2-ethylhexyl)phthalate and mono(2-ethylhexyl)phthalate in media for in vitro fertilization. CHEMOSPHERE 2012; 86:454-459. [PMID: 22024100 DOI: 10.1016/j.chemosphere.2011.09.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/07/2011] [Accepted: 09/11/2011] [Indexed: 05/31/2023]
Abstract
In vitro fertilization (IVF) is one of the most important treatments of infertility to provide a chance of conceiving. In IVF treatment, sperm are washed and motile sperm are isolated with sperm washing media (SWM) for the purpose of fertilization; fertilized ova are then incubated for a maximum of 5 or 6d in media for IVF (IVFM). The exposure of fertilized ova to chemicals via such media has not been studied. We determined the concentrations of two contaminants; di(2-ethylhexyl)phthalate (DEHP) and its hydrolyzed product mono(2-ethylhexyl)phthalate (MEHP) in IVFM, SWM, and protein sources (PS: human serum albumin or serum substitute) for IVFM and SWM. The DEHP and MEHP in these media were extracted by a liquid-liquid extraction method and their concentrations determined by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Fifteen IVFM, nine SWM, and six PS obtained in Japan were examined. The concentrations of DEHP and MEHP in IVFM and SWM were <10-114 and <2.0-263 ng mL(-1), respectively. The concentrations of both DEHP and MEHP were higher in the media containing PS than in those without PS. Either MEHP alone or both DEHP and MEHP were detected in PS. The concentrations of DEHP and MEHP in PS were <10-982 and 47.0-1840 ng mL(-1), respectively. The DEHP and MEHP detected in these media were derived from PS. This is the first study on the chemical contamination of IVFM, SWM, and PS.
Collapse
Affiliation(s)
- Satoshi Takatori
- Department of Food, Drugs and Environment, Osaka Prefectural Institute of Public Health, 1-3-69 Nakamichi, Higashinari-ku, Osaka 537-0025, Japan
| | | | | | | | | | | |
Collapse
|
12
|
Inhibitors of testosterone biosynthetic and metabolic activation enzymes. Molecules 2011; 16:9983-10001. [PMID: 22138857 PMCID: PMC6264586 DOI: 10.3390/molecules16129983] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 11/21/2011] [Accepted: 11/21/2011] [Indexed: 01/16/2023] Open
Abstract
The Leydig cells of the testis have the capacity to biosynthesize testosterone from cholesterol. Testosterone and its metabolically activated product dihydrotestosterone are critical for the development of male reproductive system and spermatogenesis. At least four steroidogenic enzymes are involved in testosterone biosynthesis: Cholesterol side chain cleavage enzyme (CYP11A1) for the conversion of cholesterol into pregnenolone within the mitochondria, 3β-hydroxysteroid dehydrogenase (HSD3B), for the conversion of pregnenolone into progesterone, 17α-hydroxylase/17,20-lyase (CYP17A1) for the conversion of progesterone into androstenedione and 17β-hydroxysteroid dehydrogenase (HSD17B3) for the formation of testosterone from androstenedione. Testosterone is also metabolically activated into more potent androgen dihydrotestosterone by two isoforms 5α-reductase 1 (SRD5A1) and 2 (SRD5A2) in Leydig cells and peripheral tissues. Many endocrine disruptors act as antiandrogens via directly inhibiting one or more enzymes for testosterone biosynthesis and metabolic activation. These chemicals include industrial materials (perfluoroalkyl compounds, phthalates, bisphenol A and benzophenone) and pesticides/biocides (methoxychlor, organotins, 1,2-dibromo-3-chloropropane and prochloraz) and plant constituents (genistein and gossypol). This paper reviews these endocrine disruptors targeting steroidogenic enzymes.
Collapse
|
13
|
Ma X, Lian QQ, Dong Q, Ge RS. Environmental inhibitors of 11β-hydroxysteroid dehydrogenase type 2. Toxicology 2011; 285:83-9. [DOI: 10.1016/j.tox.2011.04.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 03/21/2011] [Accepted: 04/08/2011] [Indexed: 10/18/2022]
|
14
|
Lee YJ, Ahn MY, Kim HS, Kwack SJ, Park KL, Yoon S, Min D. Role of phospholipase D in regulation of testicular Leydig cell hyperplasia in Sprague–Dawley rats treated with di(2-ethylhexyl) phthalate. Arch Toxicol 2010; 85:975-85. [DOI: 10.1007/s00204-010-0618-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Accepted: 10/14/2010] [Indexed: 10/18/2022]
|
15
|
Fan J, Traore K, Li W, Amri H, Huang H, Wu C, Chen H, Zirkin B, Papadopoulos V. Molecular mechanisms mediating the effect of mono-(2-ethylhexyl) phthalate on hormone-stimulated steroidogenesis in MA-10 mouse tumor Leydig cells. Endocrinology 2010; 151:3348-62. [PMID: 20463053 PMCID: PMC2903930 DOI: 10.1210/en.2010-0010] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Di-(2-ethylhexyl) phthalate, a widely used plasticizer, and its active metabolite, mono-(2-ethylhexyl) phthalate (MEHP), have been shown to exert adverse effects on the reproductive tract in developing and adult animals. As yet, however, the molecular mechanisms by which they act are uncertain. In the present study, we address the molecular and cellular mechanisms underlying the effects of MEHP on basal and human chorionic gonadotropin (hCG)-stimulated steroid production by MA-10 Leydig cells, using a systems biology approach. MEHP induced dose-dependent decreases in hCG-stimulated steroid formation. Changes in mRNA and protein expression in cells treated with increasing concentrations of MEHP in the presence or absence of hCG were measured by gene microarray and protein high-throughput immunoblotting analyses, respectively. Expression profiling indicated that low concentrations of MEHP induced the expression of a number of genes that also were expressed after hCG stimulation. Cross-comparisons between the hCG and MEHP treatments revealed two genes, Anxa1 and AR1. We suggest that these genes may be involved in a new self-regulatory mechanism of steroidogenesis. The MEHP-induced decreases in hCG-stimulated steroid formation were paralleled by increases in reactive oxygen species generation, with the latter mediated by the Cyp1a1 gene and its network. A model for the mechanism of MEHP action on MA-10 Leydig cell steroidogenesis is proposed.
Collapse
Affiliation(s)
- Jinjiang Fan
- The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Room C10-148, Montreal, Quebec, Canada H3G 1A4
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Zhao B, Chu Y, Huang Y, Hardy DO, Lin S, Ge RS. Structure-dependent inhibition of human and rat 11β-hydroxysteroid dehydrogenase 2 activities by phthalates. Chem Biol Interact 2010; 183:79-84. [DOI: 10.1016/j.cbi.2009.09.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 09/15/2009] [Accepted: 09/18/2009] [Indexed: 10/20/2022]
|
17
|
Lee YJ, Lee E, Kim TH, Choi JS, Lee J, Jung KK, Kwack SJ, Kim KB, Kang TS, Han SY, Lee BM, Kim HS. Effects of Di(2-ethylhexyl) Phthalate on Regulation of Steroidogenesis or Spermatogenesis in Testes of Sprague-Dawley Rats. ACTA ACUST UNITED AC 2009. [DOI: 10.1248/jhs.55.380] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Ena Lee
- College of Pharmacy, Pusan National University
| | | | | | - Jaewon Lee
- College of Pharmacy, Pusan National University
| | - Ki Kyung Jung
- National Institute of Toxicological Research, Korea Food and Drug Administration
| | - Seung Jun Kwack
- National Institute of Toxicological Research, Korea Food and Drug Administration
| | - Kyu Bong Kim
- National Institute of Toxicological Research, Korea Food and Drug Administration
| | - Tae Seok Kang
- National Institute of Toxicological Research, Korea Food and Drug Administration
| | - Soon Young Han
- National Institute of Toxicological Research, Korea Food and Drug Administration
| | - Byung Mu Lee
- Division of Toxicology, College of Pharmacy, Sungkyunkwan University
| | | |
Collapse
|
18
|
Barnabé S, Beauchesne I, Cooper DG, Nicell JA. Plasticizers and their degradation products in the process streams of a large urban physicochemical sewage treatment plant. WATER RESEARCH 2008; 42:153-62. [PMID: 17706266 DOI: 10.1016/j.watres.2007.07.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2007] [Revised: 07/21/2007] [Accepted: 07/24/2007] [Indexed: 05/16/2023]
Abstract
The plasticizers bis (2-ethylhexyl) phthalate (BEHP), bis (2-ethylhexyl) terephthalate (BEHTP) and bis (2-ethylhexyl) adipate (BEHA) were found in significant quantities in the influents, process streams, treated effluent and solid residues of a large physicochemical treatment plant in Montreal, Canada. Of these plasticizers, BEHA was the most abundant in the influent but most was removed during primary treatment. Evidence indicated that significant biodegradation occurred within the sewers and during treatment resulting in the formation of three biodegradation products that had been reported in earlier laboratory studies; namely, 2-ethylhexanol, 2-ethylhexanal and 2-ethylhexanoic acid. Significantly greater concentrations of 2-ethylhexanal were found in process streams than had been reported in earlier laboratory work. This was attributed to the fact that there were fewer opportunities for losses of this volatile compound over the course of wastewater treatment. The plasticizers were removed from the aqueous phase to varying degrees during treatment, with most ending up in the solid residues. All three metabolites and the parent plasticizers were observed in the effluent and most were found in the solids that were analyzed. Results suggest that the treatment plant does not effectively remove plasticizers from the influent and represents a significant source of these compounds and their degradation products in the environment.
Collapse
Affiliation(s)
- S Barnabé
- Department of Civil Engineering and Applied Mechanics, McGill University, 817 Sherbrooke Street West, Montréal, Québec, Canada H3A 2K6
| | | | | | | |
Collapse
|
19
|
Moffit JS, Bryant BH, Hall SJ, Boekelheide K. Dose-dependent effects of sertoli cell toxicants 2,5-hexanedione, carbendazim, and mono-(2-ethylhexyl) phthalate in adult rat testis. Toxicol Pathol 2007; 35:719-27. [PMID: 17763286 DOI: 10.1080/01926230701481931] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Sertoli cells are the primary cellular target for a number of pharmaceutical and environmental testicular toxicants, including 2,5-hexanedione, carbendazim, and mono-(2-ethylhexyl) phthalate. Exposure to these individual compounds can result in impaired Sertoli cell function and subsequent germ cell loss. The loss of testicular function is marked by histopathological changes in seminiferous tubule diameter, seminiferous epithelial sloughing, vacuolization, spermatid head retention, germ cell apoptosis, and altered microtubule assembly. The present study investigates dose-response relationships for these classic Sertoli cell toxicants using histopathology endpoints. Understanding the relationship between the Sertoli cell toxicant dose and its histopathologic manifestations will help establish the sensitivity of these endpoints as markers of testicular injury. The results indicate that no single histopathology endpoint was sensitive on its own in identifying altered testicular morphology resulting from toxicant exposure. However, when multiple endpoints were combined dose-response relationships could be associated with incremental alterations in histopathology. The data generated from these experiments will be useful in further investigating the effects of Sertoli cell toxicant exposure in animal toxicity studies. In addition, this work is fundamental to a planned investigation of the histopathologic and gene expression changes associated with testicular toxicant co-exposures, which may occur both occupationally and environmentally.
Collapse
Affiliation(s)
- Jeffrey S Moffit
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island 02912, USA
| | | | | | | |
Collapse
|
20
|
Suna S, Yamaguchi F, Kimura S, Tokuda M, Jitsunari F. Preventive effect of d-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury in rat. Toxicol Lett 2007; 173:107-17. [PMID: 17698303 DOI: 10.1016/j.toxlet.2007.06.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Revised: 06/28/2007] [Accepted: 06/29/2007] [Indexed: 10/23/2022]
Abstract
To investigate the preventive effects of d-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury, prepubertal male Sprague-Dawley rats were exposed to DEHP via their diet or orally, while under treatment with d-psicose. The rats given a diet-containing 1% DEHP alone for 7-14 days showed severe testicular atrophy accompanied by aspermatogenesis. On the other hand, those given the diet plus 2% but not 1% d-psicose-supplemented water for 14 days did not develop testicular atrophy, and exhibited an almost complete spermatogenesis. There was no significant difference in plasma mono-(2-ethylhexyl) phthalate (MEHP) levels between the d-psicose-free and d-psicose-treated groups. The testicular malondialdehyde (MDA) level after a single oral administration of 2g/kg of DEHP showed a similar pattern of increase to the plasma MEHP level and peaked in 24h suggesting a close and dose-dependent relation between plasma MEHP and testicular reactive oxygen species (ROS) levels. Pretreatment with d-psicose at a concentration of 2% and 4% resulted in an almost complete but not absolute suppression of testicular MDA production among rats administered 2g/kg of DEHP. The microarray analysis showed the induction of oxidative stress related genes including the thioredoxin, glutathione peroxidase 1 and 2, glutaredoixn 1 after 24h of the DEHP treatment in the testis. These results show that d-psicose prevents DEHP-induced testicular injury by suppressing the generation of ROS in the rat testis. This effect may be due to the direct scavenging by d-psicose of ROS generated in the testis.
Collapse
Affiliation(s)
- Shigeru Suna
- Department of Hygiene and Public Health, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki, Kagawa 761-0793, Japan.
| | | | | | | | | |
Collapse
|
21
|
Ryu JY, Whang J, Park H, Im JY, Kim J, Ahn MY, Lee J, Kim HS, Lee BM, Yoo SD, Kwack SJ, Oh JH, Park KL, Han SY, Kim SH. Di(2-ethylhexyl) phthalate induces apoptosis through peroxisome proliferators-activated receptor-gamma and ERK 1/2 activation in testis of Sprague-Dawley rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:1296-303. [PMID: 17654247 DOI: 10.1080/15287390701432160] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Di(2-ethylhexyl) phthalate (DEHP) is a well-known hepatic and reproductive toxicant whose toxicity may be mediated by peroxisome proliferators-activated receptor (PPAR). This study examined the effects of DEHP on the expression of PPAR-regulated genes involved in testicular cells apoptosis. Sprague-Dawley male rats were treated orally with 250, 500, or 750 mg/kg/d DEHP for 28 d, while control rats were given corn oil. The levels of cell cycle regulators (pRb, cyclins, CDKs, and p21) and apoptosis-related proteins were analyzed by Western blot analysis. The role of PPAR-gamma (PPAR-gamma), class B scavenger receptor type 1 (SR-B1), and ERK1/2 was further studied to examine the signaling pathway for DEHP-induced apoptosis. Results showed that the levels of pRB, cyclin D, CDK2, cyclin E, and CDK4 were significantly lower in rats given 500 and 750 mg/kg/d DEHP, while levels of p21 were significantly higher in rat testes. Dose-dependent increases in PPAR-gamma and RXRalpha proteins were observed in testes after DEHP exposure, while there was a significant decrease in RXRgamma protein levels. In addition to PPAR-gamma, DEHP also significantly increased SR-B1 mRNA and phosphorylated ERK1/2 protein levels. Furthermore, DEHP treatment induced pro-caspase-3 and cleavage of its substrate protein, poly(ADP-ribose) polymerase (PARP), in a dose-dependent manner. Data suggest that DEHP exposure may induce the expression of apoptosis-related genes in testes through induction of PPAR-gamma and activation of the ERK1/2 pathway.
Collapse
Affiliation(s)
- Ju Young Ryu
- College of Pharmacy, Pusan National University, Pusan, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Ito Y, Yamanoshita O, Kurata Y, Kamijima M, Aoyama T, Nakajima T. Induction of peroxisome proliferator-activated receptor alpha (PPARalpha)-related enzymes by di(2-ethylhexyl) phthalate (DEHP) treatment in mice and rats, but not marmosets. Arch Toxicol 2006; 81:219-26. [PMID: 16937134 DOI: 10.1007/s00204-006-0141-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2006] [Accepted: 07/31/2006] [Indexed: 10/24/2022]
Abstract
To clarify species differences in the induction of peroxisome proliferator-activated receptor alpha (PPARalpha)-related enzymes by di(2-ethylhexyl)phthalate (DEHP) exposure, we investigated the inductions of PPARalpha and its target genes (mitochondrial medium-chain acyl-CoA dehydrogenase (MCAD) and peroxisomal keto-acyl-CoA thiolase (PT) in liver from mice (CD-1), rats (Sprague-Dawley), and marmosets (Callithrix jacchus) exposed to DEHP. Male mice and rats were treated with 0, 1.25 and 2.5 mmol/kg DEHP for 2 weeks, and marmosets with 0, 0.25, 1.25 and 6.25 mmol/kg DEHP for 15 months by gavage. Hepatic mono(2-ethylhexyl)phthalate (MEHP) levels were significantly higher in mice and rats than in marmosets. The constitutive expression of hepatic PPARalpha was 5-7 times greater in rats and mice than in marmosets, but DEHP treatment did not induce PPARalpha-mRNA in all animals. The treatment-induced PT expression detected either by anti-PT antibody or PT-mRNA levels in the liver only from mice and rats, and the induction of the mRNA was greater in the latter than in the former. Thus, DEHP used in this experiment influenced the peroxisomal enzymes in mice and rats, but did not affect the mitochondrial enzymes in any animals or the peroxisomal enzymes in marmosets. These results suggest that there are species differences in the induction of PPARalpha-related enzymes, especially in peroxisomal enzymes by DEHP treatment, and their underlying mechanism may in part reside in the different constitutive levels of PPARalpha and different forming levels of MEHP.
Collapse
Affiliation(s)
- Yuki Ito
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan
| | | | | | | | | | | |
Collapse
|
23
|
Kang JS, Morimura K, Toda C, Wanibuchi H, Wei M, Kojima N, Fukushima S. Testicular toxicity of DEHP, but not DEHA, is elevated under conditions of thioacetamide-induced liver damage. Reprod Toxicol 2006; 21:253-9. [PMID: 16303285 DOI: 10.1016/j.reprotox.2005.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Revised: 09/28/2005] [Accepted: 09/30/2005] [Indexed: 11/30/2022]
Abstract
As part of an investigation of possible enhancement by liver disease of testicular toxicity caused by phthalates, we tested the effects of di(2-ethylhexyl)phthalate (DEHP) and di(2-ethylhexyl)adipate (DEHA) in a thioacetamide (TAA)-induced rat liver damage model. Male, 6-week-old, F344 rats (n=60) were divided into ten groups. Animals of groups 1-5 received TAA (200 mg/kg, intraperitoneal, three times per week) for 4 weeks, and groups 6-10 served as controls without TAA. After a 1 week interval, at week 5, powder diet containing DEHP or DEHA was provided to the animals of groups 1 and 6 (DEHP 25000 ppm), groups 2 and 7 (DEHP 6000 ppm), groups 3 and 8 (DEHA 25000 ppm) and groups 4 and 9 (DEHA 6000 ppm), while groups 5 and 10 received basal diet. All animals were sacrificed at week 9. Significant decrease in sperm numbers and motility and increase in morphology abnormalities were evident in group 1 as compared to groups 5 and 6 (p<0.01). However, DEHA treatment was not associated with any apparent testicular toxicity in either TAA- or vehicle-treated animals. Histopathological examination of the testes revealed severe atrophy and degeneration of testicular tubules in all animals given TAA and DEHP at high dose, only mild to moderate lesions being found with DEHP alone. We conclude that liver toxicity induced by TAA is associated with the enhancement of testicular toxicity of DEHP, but not DEHA, in rats.
Collapse
Affiliation(s)
- Jin Seok Kang
- Department of Pathology, Osaka City University Medical School, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan
| | | | | | | | | | | | | |
Collapse
|
24
|
Main KM, Mortensen GK, Kaleva MM, Boisen KA, Damgaard IN, Chellakooty M, Schmidt IM, Suomi AM, Virtanen HE, Petersen DVH, Andersson AM, Toppari J, Skakkebaek NE. Human breast milk contamination with phthalates and alterations of endogenous reproductive hormones in infants three months of age. ENVIRONMENTAL HEALTH PERSPECTIVES 2006; 114:270-6. [PMID: 16451866 PMCID: PMC1367843 DOI: 10.1289/ehp.8075] [Citation(s) in RCA: 312] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
UNLABELLED Phthalates adversely affect the male reproductive system in animals. We investigated whether phthalate monoester contamination of human breast milk had any influence on the postnatal surge of reproductive hormones in newborn boys as a sign of testicular dysgenesis. DESIGN We obtained biologic samples from a prospective Danish-Finnish cohort study on cryptorchidism from 1997 to 2001. We analyzed individual breast milk samples collected as additive aliquots 1-3 months postnatally (n = 130; 62 cryptorchid/68 healthy boys) for phthalate monoesters [mono-methyl phthalate (mMP), mono-ethyl phthalate (mEP), mono-n-butyl phthalate (mBP), mono-benzyl phthalate (mBzP), mono-2-ethylhexyl phthalate (mEHP), mono-isononyl phthalate (miNP)]. We analyzed serum samples (obtained in 74% of all boys) for gonadotropins, sex-hormone binding globulin (SHBG), testosterone, and inhibin B. RESULTS All phthalate monoesters were found in breast milk with large variations [medians (minimum-maximum)]: mMP 0.10 (< 0.01-5.53 microg/L), mEP 0.95 (0.07-41.4 microg/L), mBP 9.6 (0.6-10,900 microg/L), mBzP 1.2 (0.2-26 microg/L), mEHP 11 (1.5-1,410 microg/L), miNP 95 (27-469 microg/L). Finnish breast milk had higher concentrations of mBP, mBzP, mEHP, and Danish breast milk had higher values for miNP (p = 0.0001-0.056). No association was found between phthalate monoester levels and cryptorchidism. However, mEP and mBP showed positive correlations with SHBG (r = 0.323, p = 0.002 and r = 0.272, p = 0.01, respectively); mMP, mEP, and mBP with LH:free testosterone ratio (r = 0.21-0.323, p = 0.002-0.044) and miNP with luteinizing hormone (r = 0.243, p = 0.019). mBP was negatively correlated with free testosterone (r = -0.22, p = 0.033). Other phthalate monoesters showed similar but nonsignificant tendencies. CONCLUSIONS Our data on reproductive hormone profiles and phthalate exposures in newborn boys are in accordance with rodent data and suggest that human Leydig cell development and function may also be vulnerable to perinatal exposure to some phthalates. Our findings are also in line with other recent human data showing incomplete virilization in infant boys exposed to phthalates prenatally.
Collapse
Affiliation(s)
- Katharina M Main
- University Department of Growth and Reproduction, Rigshospitalet, Copenhagen, Denmark.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Kurahashi N, Kondo T, Omura M, Umemura T, Ma M, Kishi R. The Effects of Subacute Inhalation of Di (2‐ethylhexyl) Phthalate (DEHP) on the Testes of Prepubertal Wistar Rats. J Occup Health 2005; 47:437-44. [PMID: 16230838 DOI: 10.1539/joh.47.437] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In animal studies using oral dosing for short periods, di (2-ethylhexyl) phthalate (DEHP) is well known for its reproductive toxicity, especially for its testicular toxicity. However, extending the period of DEHP exposure in prepubertal rats resulted in significant increases in testosterone. This suggests that the reproductive effect of DEHP might be associated with the timing and the term of exposure. Moreover, the route of exposure may induce differences in its effect because tissue levels of metabolites of DEHP after inhalation are thought to be different from those after oral administration. We researched the effects of inhalation of DEHP on testes of prepubertal rats. Our results showed that inhalation of DEHP by 4-wk-old male Wistar rats at doses of 5 or 25 mg/m(3), 6 h per day, for 4 and 8 wk significantly increased the concentration of plasma testosterone and weight of seminal vesicles. However, the concentration of luteinizing hormone (LH), follicular stimulating hormone (FSH) and the expression of mRNAs of androgen biosynthesis enzyme, cytochrome P450 cholesterol side-chain-cleavage enzyme (P450scc), 3beta-hydroxysteroid dehydrogenase (3beta-HSD), cytochrome P450 17alpha-hydroxylase/17, 20 lyase (CYP17) and aromatase (CYP19) did not change. Rats with precocious testes did not increase in any of the DEHP groups. We also found that the estimated effective dose in this study was less than those reported in previous studies which used oral dosing. Our study showed that inhaled DEHP increased plasma testosterone concentrations in prepubertal rats and suggested that their effects were more sensitive to inhalation of DEHP than oral dosing.
Collapse
Affiliation(s)
- Norie Kurahashi
- Department of Public Health, Hokkaido University Graduate School of Medicine, Japan
| | | | | | | | | | | |
Collapse
|
26
|
Mortensen GK, Main KM, Andersson AM, Leffers H, Skakkebaek NE. Determination of phthalate monoesters in human milk, consumer milk, and infant formula by tandem mass spectrometry (LC-MS-MS). Anal Bioanal Chem 2005; 382:1084-92. [PMID: 15933851 DOI: 10.1007/s00216-005-3218-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 02/25/2005] [Accepted: 03/15/2005] [Indexed: 11/27/2022]
Abstract
Daily exposure of humans to phthalates may be a health risk because animal experiments have shown these compounds can affect the differentiation and function of the reproductive system. Because milk is the main source of nutrition for infants, knowledge of phthalate levels is important for exposure and risk assessment. Here we describe the development and validation of a quantitative analytical procedure for determination of phthalate metabolites in human milk. The phthalate monoesters investigated were: monomethyl phthalate (mMP), monoethyl phthalate (mEP), mono-n-butyl phthalate (mBP), monobenzyl phthalate (mBzP), mono-(2-ethylhexyl) phthalate (mEHP), and monoisononyl phthalate (mNP). The method is based on liquid extraction with a mixture of ethyl acetate and cyclohexane (95:5) followed by two-step solid-phase extraction (SPE). Detection and quantification of the phthalate monoesters were accomplished by high-pressure liquid chromatography using a Betasil phenyl column (100 mmx2.1 mmx3 microm) and triple tandem mass spectrometry (LC-MS-MS). Detection limits were in the range 0.01 to 0.5 microg L(-1) and method variation was from 5 to 15%. Analysis of 36 milk samples showed that all these phthalates were present, albeit at different concentrations. Median values (microg L(-1)) obtained were 0.11 (mMP), 0.95 (mEP), 3.5 (mBP), 0.8 (mBzP), 9.5 (mEHP), and 101 (mNP). We also analysed seven samples of consumer milk and ten samples of infant formula. Only mBP and mEHP were detected in these samples, in the ranges 0.6-3.9 microg L(-1) (mBP) and 5.6-9.9 microg L(-1) (mEHP).
Collapse
Affiliation(s)
- Gerda K Mortensen
- Department of Growth and Reproduction, Copenhagen University Hospital , Rigshospitalet, Section 5064, Blegdamsvej 9, 2100 Copenhagen, Denmark.
| | | | | | | | | |
Collapse
|
27
|
Bhattacharya N, Dufour JM, Vo MN, Okita J, Okita R, Kim KH. Differential Effects of Phthalates on the Testis and the Liver1. Biol Reprod 2005; 72:745-54. [PMID: 15564602 DOI: 10.1095/biolreprod.104.031583] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Phthalates have been shown to elicit contrasting effects on the testis and the liver, causing testicular degeneration and promoting abnormal hepatocyte proliferation and carcinogenesis. In the present study, we compared the effects of phthalates on testicular and liver cells to better understand the mechanisms by which phthalates cause testicular degeneration. In vivo treatment of rats with di-(2-ethylhexyl) phthalate (DEHP) caused a threefold increase of germ cell apoptosis in the testis, whereas apoptosis was not changed significantly in livers from the same animals. Western blot analyses revealed that peroxisome proliferator-activated receptor (PPAR) alpha is equally abundant in the liver and the testis, whereas PPAR gamma and retinoic acid receptor (RAR) alpha are expressed more in the testis. To determine whether the principal metabolite of DEHP, mono-(2-ethylhexyl) phthalate (MEHP), or a strong peroxisome proliferator, 4-chloro-6(2,3-xylindino)-2-pyrimidinylthioacetic acid (Wy-14,643), have a differential effect in Sertoli and liver cells by altering the function of RAR alpha and PPARs, their nuclear trafficking patterns were compared in Sertoli and liver cells after treatment. Both MEHP and Wy-14,643 increased the nuclear localization of PPAR alpha and PPAR gamma in Sertoli cells, but they decreased the nuclear localization of RAR alpha, as previously shown. Both PPAR alpha and PPAR gamma were in the nucleus and cytoplasm of liver cells, but RAR alpha was predominant in the cytoplasm, regardless of the treatment. At the molecular level, MEHP and Wy-14,643 reduced the amount of phosphorylated mitogen-activated protein kinase (activated MAPK) in Sertoli cells. In comparison, both MEHP and Wy-14,643 increased phosphorylated MAPK in liver cells. These results suggest that phthalates may cause contrasting effects on the testis and the liver by differential activation of the MAPK pathway, RAR alpha, PPAR alpha, and PPAR gamma in these organs.
Collapse
Affiliation(s)
- Nandini Bhattacharya
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington 99164, USA
| | | | | | | | | | | |
Collapse
|
28
|
Rasoulpour RJ, Boekelheide K. NF-κB Is Activated in the Rat Testis Following Exposure to Mono-(2-Ethylhexyl) Phthalate. Biol Reprod 2005; 72:479-86. [PMID: 15496515 DOI: 10.1095/biolreprod.104.034363] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The process of spermatogenesis requires a delicate balance of proapoptotic and antiapoptotic signaling to maintain optimal sperm output. A major transcription factor known to regulate numerous apoptosis-related genes is NF-kappaB. Here we show that mono-(2-ethylhexyl) phthalate (MEHP, 1 g/kg) induces translocation of NF-kappaB subunits (p65, p50, and c-Rel) to germ cell nuclei in young rats (Postnatal Day 28) as early as 1 h after exposure. Immunohistochemistry of rat testes exposed to MEHP showed increased p50 and c-Rel presence in spermatocytes and spermatogonia. In addition, there was increased p65 nuclear positivity in Sertoli cells and germ cells after MEHP, while Rel-B localization was unchanged. These alterations correlated with increased nuclear NF-kappaB-binding activity after MEHP exposure, as shown by electrophoretic mobility shift assays of whole-testis nuclear protein extracts. The increased activity of this transcription factor was associated with a transient protection of the seminiferous epithelium manifested as a decreased number of germ cell apoptotic nuclei measured by TUNEL assay 6 h after MEHP exposure. These results suggest that NF-kappaB is involved in the testicular response to MEHP-induced injury.
Collapse
Affiliation(s)
- Reza J Rasoulpour
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island 02912, USA
| | | |
Collapse
|
29
|
Takatori S, Kitagawa Y, Kitagawa M, Nakazawa H, Hori S. Determination of di(2-ethylhexyl)phthalate and mono(2-ethylhexyl)phthalate in human serum using liquid chromatography-tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 804:397-401. [PMID: 15081935 DOI: 10.1016/j.jchromb.2004.01.056] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2003] [Revised: 01/27/2004] [Accepted: 01/27/2004] [Indexed: 11/19/2022]
Abstract
Concentrations of mono(2-ethylhexyl)phthalate (MEHP), and di(2-ethylhexyl)phthalate (DEHP), in serum of healthy volunteers were determined by high performance liquid chromatography (HPLC) with tandem mass spectrometry (LC/MS/MS). The serum was extracted with acetone, followed by hexane extraction under acidic conditions, and then applied to the LC/MS/MS. Recoveries of 20 ng/ml of MEHP and DEHP were 101+/-5.7 (n=6) and 102+/-6.5% (n=6), respectively. The limits of quantification (LOQ) of MEHP and DEHP in the method were 5.0 and 14.0 ng/ml, respectively. The concentration of MEHP in the serum was at or less than the LOQ. The concentration of DEHP in the serum was less than the LOQ. Contaminations of MEHP and DEHP from experimental reagents, apparatus and air during the procedure were less than the LOQ and were estimated to be <1.0 and 2.2+/-0.6 ng/ml, respectively. After subtraction of the contamination, the net concentrations of MEHP and DEHP in the serum were estimated at or <5 and <2 ng/ml, respectively. To decrease contamination by DEHP, the cleanup steps and the apparatus and solvent usage were minimized in the sample preparation procedures. The high selectivity of LC/MS/MS is the key for obtaining reliable experimental data from in the matrix-rich analytical samples and for maintaining a low level contamination of MEHP and DEHP in this experimental system. This method would be a useful tool for the detection of MEHP and DEHP in serum.
Collapse
Affiliation(s)
- S Takatori
- Osaka Prefectural Institute of Public Health, 3-69, 1-chome, Nakamichi, Higashinari-ku, Osaka 537-0025, Japan.
| | | | | | | | | |
Collapse
|
30
|
Ito Y, Yokota H, Wang R, Yamanoshita O, Ichihara G, Wang H, Kurata Y, Takagi K, Nakajima T. Species differences in the metabolism of di(2-ethylhexyl) phthalate (DEHP) in several organs of mice, rats, and marmosets. Arch Toxicol 2004; 79:147-54. [PMID: 15798888 DOI: 10.1007/s00204-004-0615-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2004] [Accepted: 09/23/2004] [Indexed: 11/30/2022]
Abstract
To clarify species differences in the metabolism of di(2-ethylhexyl) phthalate (DEHP) we measured the activity of four DEHP-metabolizing enzymes (lipase, UDP-glucuronyltransferase (UGT), alcohol dehydrogenase (ADH), and aldehyde dehydrogenase (ALDH)) in several organs (the liver, lungs, kidneys, and small intestine) of mice (CD-1), rats (Sprague-Dawley), and marmosets (Callithrix jacchus). Lipase activity, measured by the rate of formation of mono(2-ethylhexyl) phthalate (MEHP) from DEHP, differed by 27- to 357-fold among species; the activity was highest in the small intestines of mice and lowest in the lungs of marmosets. This might be because of the significant differences between Vmax/Km values of lipase for DEHP among the species. UGT activity for MEHP in the liver microsomes was highest in mice, followed by rats and marmosets. These differences, however, were only marginal compared with those for lipase activity. ADH and ALDH activity also differed among species; the activity of the former in the livers of marmosets was 1.6-3.9 times greater than in those of rats or mice; the activity of the latter was higher in rats and marmosets (2-14 times) than in mice. These results were quite different from those for lipase or UGT activity. Because MEHP is considered to be the more potent ligand to peroxisome proliferator-activated receptor alpha involved in different toxic processes, a possibly major difference in MEHP-formation capacity could be also considered on extrapolation from rodents to humans.
Collapse
Affiliation(s)
- Yuki Ito
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 466-8550, Nagoya, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Akingbemi BT, Ge R, Klinefelter GR, Zirkin BR, Hardy MP. Phthalate-induced Leydig cell hyperplasia is associated with multiple endocrine disturbances. Proc Natl Acad Sci U S A 2004; 101:775-80. [PMID: 14715905 PMCID: PMC321757 DOI: 10.1073/pnas.0305977101] [Citation(s) in RCA: 258] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2003] [Indexed: 11/18/2022] Open
Abstract
The possibility that exposures to environmental agents are associated with reproductive disorders in human populations has generated much public interest recently. Phthalate esters are used most commonly as plasticizers in the food and construction industry, and di-(2-ethylhexyl) phthalate (DEHP) is the most abundant phthalate in the environment. Daily human exposure to DEHP in the U.S. is significant, and occupational and clinical exposures from DEHP-plasticized medical devices, e.g., blood bags, hemodialysis tubing, and nasogastric feeding tubes, increase body burden levels. We investigated the effects of chronic exposures to low environmentally relevant DEHP levels on testicular function. Our data show that prolonged exposures to this agent induced high levels of the gonadotropin luteinizing hormone and increased the serum concentrations of sex hormones [testosterone and 17beta-estradiol (E2)] by >50%. Increased proliferative activity in Leydig cells was evidenced by enhanced expression of cell cycle proteins, as determined by RT-PCR. The numbers of Leydig cells in the testis of DEHP-treated rats were 40-60% higher than in control rats, indicating induction of Leydig cell hyperplasia. DEHP-induced elevations in serum testosterone and E2 levels suggest the possibility of multiple crosstalks between androgen, estrogen, and steroid hormone receptors, whereas the presence of estrogen receptors in nonreproductive tissues, e.g., cardiovascular system and bones, implies that the increases in serum E2 levels have implications beyond reproduction, including systemic physiology. Analysis of the effects of phthalate exposures on gonadotropin and steroid hormone levels should form part of overall risk assessment in human populations.
Collapse
Affiliation(s)
- Benson T Akingbemi
- Center for Biomedical Research, Population Council, New York, NY 10021, USA
| | | | | | | | | |
Collapse
|
32
|
Ono H, Saito Y, Imai K, Kato M. SUBCELLULAR DISTRIBUTION OF DI-(2-ETHYLHEXYL)PHTHALATE IN RAT TESTIS. J Toxicol Sci 2004; 29:113-24. [PMID: 15206579 DOI: 10.2131/jts.29.113] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Subcellular distribution of di-(2-ethylhexyl)phthalate (DEHP) in the testis was studied by single oral administration of [3,4,5,6-(3)H]-phthalic acid di-(2-ethylhexyl) ester (DEHP-3H) or phthalic acid di-(2-ethyl[1-(3)H]hexyl) ester (3H-DEHP) to 8-week-old male rats. Autoradiographs and electron microscopic autoradiographs were prepared from the testis, liver and kidney at 6 and 24 hr after administration and distribution of radioactive materials in the tissues were observed. In the autoradiographic specimen at 6 hr after administration of DEHP 3H-labeled at phthalic acid moiety (DEHP-3H), many grains were observed in the testis, mainly at the basal area of seminiferous tubules at the stages IX to I of the spermatogenic cycle. Electron microscopic autoradiographs taken at the same time revealed that localization of grains were in the smooth-surfaced endoplasmic reticulum and mitochondria of Sertoli cells. A few grains were also present at the Golgi apparatus and lysosome of Sertoli cells, and at the interfaces between the Sertoli cells or between Sertoli cells and spermatocytes, and in the cytoplasm of spermatocytes. Autoradiographs of the liver revealed grains in the centrilobular hepatocytes, localized at mitochondria, rough-surfaced endoplasmic reticulum and peroxisomes. In the kidney, the radioactivity was localized at the brush border of the tubular cells in the pars recta of proximal tubules. In the 24-hr specimen, the grain density in the seminiferous tubules obviously decreased. On the other hand, by autoradiography with DEHP 3H-labeled at the alcohol (3H-DEHP), only a few grains were observed in autoradiographs of the testes at 6 hr after administration. No grains were noted in autoradiographs of the liver and kidney with 3H-DEHP. The results showed that the phthalic acid ester was splitted rapidly in the body and only the phthalic acid moiety distributed into the cells.
Collapse
Affiliation(s)
- Hiroshi Ono
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan
| | | | | | | |
Collapse
|
33
|
Hurst CH, Waxman DJ. Activation of PPARalpha and PPARgamma by environmental phthalate monoesters. Toxicol Sci 2003; 74:297-308. [PMID: 12805656 DOI: 10.1093/toxsci/kfg145] [Citation(s) in RCA: 365] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Phthalate esters are widely used as plasticizers in the manufacture of products made of polyvinyl chloride. Mono-(2-ethylhexyl)-phthalate (MEHP) induces rodent hepatocarcinogenesis by a mechanism that involves activation of the nuclear transcription factor peroxisome proliferator-activated receptor-alpha (PPARalpha). MEHP also activates PPAR-gamma (PPARgamma), which contributes to adipocyte differentiation and insulin sensitization. Human exposure to other phthalate monoesters, including metabolites of di-n-butyl phthalate and butyl benzyl phthalate, is substantially higher than that of MEHP, prompting this investigation of their potential for PPAR activation, assayed in COS cells and in PPAR-responsive liver (PPARalpha) and adipocyte (PPARgamma) cell lines. Monobenzyl phthalate (MBzP) and mono-sec-butyl phthalate (MBuP) both increased the COS cell transcriptional activity of mouse PPARalpha, with effective concentration for half-maximal response (EC50) values of 21 and 63 microM, respectively. MBzP also activated human PPARalpha (EC50=30 microM) and mouse and human PPARgamma (EC50=75-100 microM). MEHP was a more potent PPAR activator than MBzP or MBuP, with mouse PPARalpha more sensitive to MEHP (EC50=0.6 microM) than human PPARalpha (EC50=3.2 microM). MEHP activation of PPARgamma required somewhat higher concentrations, EC50=10.1 microM (mouse PPARgamma) and 6.2 microM (human PPARgamma). No significant PPAR activation was observed with the monomethyl, mono-n-butyl, dimethyl, or diethyl esters of phthalic acid. PPARalpha activation was verified in FAO rat liver cells stably transfected with PPARalpha, where expression of several endogenous PPARalpha target genes was induced by MBzP, MBuP, and MEHP. Similarly, activation of endogenous PPARgamma target genes was evidenced for all three phthalates by the stimulation of PPARgamma-dependent adipogenesis in the 3T3-L1 cell differentiation model. These findings demonstrate the potential of environmental phthalate monoesters for activation of rodent and human PPARs and may help to elucidate the molecular basis for the adverse health effects proposed to be associated with human phthalate exposure.
Collapse
Affiliation(s)
- Christopher H Hurst
- Department of Biology, Division of Cell and Molecular Biology, Boston University, Boston, Massachusetts 02215, USA
| | | |
Collapse
|
34
|
Silva MJ, Malek NA, Hodge CC, Reidy JA, Kato K, Barr DB, Needham LL, Brock JW. Improved quantitative detection of 11 urinary phthalate metabolites in humans using liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 789:393-404. [PMID: 12742130 DOI: 10.1016/s1570-0232(03)00164-8] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Phthalates are widely used as industrial solvents and plasticizers, with global use exceeding four million tons per year. We improved our previously developed high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometric (HPLC-APCI-MS/MS) method to measure urinary phthalate metabolites by increasing the selectivity and the sensitivity by better resolving them from the solvent front, adding three more phthalate metabolites, monomethyl phthalate (mMP), mono-(2-ethyl-5-oxohexyl)phthalate (mEOHP) and mono-(2-ethyl-5-hydroxyhexyl)phthalate (mEHHP); increasing the sample throughput; and reducing the solvent usage. Furthermore, this improved method enabled us to analyze free un-conjugated mono-2-ethylhexyl phthalate (mEHP) by eliminating interferences derived from coelution of the glucuronide-bound, or conjugated form, of the mEHP on measurements of the free mEHP. This method for measuring phthalate metabolites in urine involves solid-phase extraction followed by reversed-phase HPLC-APCI-MS/MS using isotope dilution with (13)C(4) internal standards. We further evaluated the ruggedness and the reliability of the method by comparing measurements made by multiple analysts at different extraction settings on multiple instruments. We observed mMP, monoethyl phthalate (mEP), mono-n-butyl phthalate (mBP), monobenzyl phthalate (mBzP), mEHP, mEHHP and mEOHP in the majority of urine specimens analyzed with DEHP-metabolites mEHHP and mEOHP present in significantly higher amounts than mEHP.
Collapse
Affiliation(s)
- Manori J Silva
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Mailstop F17, Atlanta, GA 30341-3724, USA.
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Lampen A, Zimnik S, Nau H. Teratogenic phthalate esters and metabolites activate the nuclear receptors PPARs and induce differentiation of F9 cells. Toxicol Appl Pharmacol 2003; 188:14-23. [PMID: 12668118 DOI: 10.1016/s0041-008x(03)00014-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Industrial plasticizers such as phthalates can induce peroxisome proliferation. Some phthalates such as di-2-ethyl-hexyl-phthalate (DEHP) and its metabolites mono-2-ethyl-hexyl-phthalate and 2-ethyl-hexanoic acid are also known teratogens. Recently, we introduced two in vitro test systems consisting of F9 teratocarcinoma cell differentiation and activation of peroxisome proliferator-activated receptor (PPAR)-ligand-binding domain in Chinese hamster ovary-reporter cells for the detection of teratogenic compounds related to the antiepileptic drug valproic acid. We now applied these methods to the class of phthalate esters and their metabolites by testing 2 diphthalate esters and 19 monophthalate esters in vitro. In the F9 cell assay only five compounds, mono-2-ethyl-hexyl-phthalate, mono-1-methyl-heptyl-phthalate, mono-benzyl-phthalate, benzyl-butyl-phthalate, and 2-ethyl-hexanoic acid were found to induce F9 cell differentiation. The other test compounds were not able to induce differentiation of F9 cells. Three compounds (mono-methyl-phthalate, mono-ethyl-phthalate, and mono-2,2-dimethyl-1-phenyl-propyl-phthalate, and phthalic acid di-methyl-ester were found not to interact with any PPARs. All other phthalate esters activated PPARs. Most compounds activated PPARalpha and PPARgamma. Interestingly PPARgamma in most cases was activated stronger than PPARalpha. Only the five test compounds, mono-2-ethyl-hexyl-phthatate, mono-1-methyl-heptyl-phthalate, mono-benzyl-phthalate, benzyl-butyl-phthalate, and 2-ethyl-hexanoic acid activated PPARdelta and interacted with a specific PPARdelta-response element. These are the same compounds that induced F9 cell differentiation and three of them are known teratogenic compounds. It is concluded that phthatate esters are acting like hormones by activating PPARs. The combination of F9 cell differentiation assay and PPARdelta activation assay detected possible teratogenic phthalate-ester and derivatives. Therefore the test systems seem useful for a screening test system in the early development of new plasticizers.
Collapse
Affiliation(s)
- Alfonso Lampen
- Zentrumsabteilung für Lebensmitteltoxikologie, Tierärztliche Hochschule Hannover, D-30173 Hannover, Germany.
| | | | | |
Collapse
|
36
|
Draper CJ, Greenwalt TJ, Dumaswala UJ. Biochemical and structural changes in RBCs stored with different plasticizers: the role of hexanol. Transfusion 2002; 42:830-5. [PMID: 12375654 DOI: 10.1046/j.1537-2995.2002.00138.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND PVC containers are plasticized with di(2-ethyl)hexylphthalate (DEHP) or a related phthalate. The toxicity of DEHP has been questioned. It has been proposed to use butyryltrihexylcitrate (BTHC) as the plasticizer. The purpose of this study was to determine if hexanol, a component of BTHC, plays a role in the preservation of RBCs stored in BTHC-plasticized PVC bags. STUDY DESIGN AND METHODS WBC-reduced RBCs of ABO- and D-matched blood groups were prepared in 1-L polyolefin (PO) bags (PL732). Six 60-g aliquots were transferred to transfer packs made of PL146 (DEHP-plasticized) and PL2209 (BTHC-plasticized) and four PO (PL732) packs. To the PL146 and PL2209 packs, 30 mL of AS-1 was added. To three of the PO packs, 30 mL of AS-1 with sufficient DEHP, BTHC, or hexanol to achieve a final concentration of 3 mM was added, and to the final PO pack, 30 mL of AS-1 only was added (control). The units were stored for 6 weeks at 1 to 6 degrees C. RBC ATP, hemolysis, morphology, membrane lipids, deformability, and fluidity were measured. RESULTS ATP levels were not significantly different in any of the systems after 6 weeks. Compared to the PO bags, hemolysis was lowest in the PL146 containers and was also significantly lower (p < 0.006) in the PO bags with added DEHP, BTHC, or hexanol. The accumulation of vesicles was significantly less in the units stored in the PL146 and PL2209 than in the PO plastic with or without added plasticizers or hexanol (p < or = 0.004). There was no significant difference in the formation of vesicles in any of the PO units (p > 0.05). There was no demonstrable change in the membrane fluidity of the RBCs during storage in any of the systems. The decrease in deformability was the same, and the losses of cholesterol and phospholipid during storage were similar in all the studies. CONCLUSIONS The hexanol component of the BHTC plasticizer in a concentration of 144.6 microg per mL concentration suppresses hemolysis and vesiculation of RBCs during storage. The hexanol and DEHP that are slowly leached during storage have a greater effect in suppressing hemolysis and vesicle formation than when added extraneously to AS-1 in PO containers.
Collapse
Affiliation(s)
- C J Draper
- Hoxworth Blood Center, University of Cincinnati Medical Center, Ohio 45267-0055, USA
| | | | | |
Collapse
|
37
|
Keire DA, Anton P, Faull KF, Ruth E, Walsh JH, Chew P, Quisimoro D, Territo M, Reeve JR. Diethyl phthalate, a chemotactic factor secreted by Helicobacter pylori. J Biol Chem 2001; 276:48847-53. [PMID: 11677249 DOI: 10.1074/jbc.m109811200] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The structure of a small-molecule, non-peptide chemotactic factor has been determined from activity purified to apparent homogeneity from Helicobacter pylori supernatants. H. pylori was grown in brucella broth media until one liter of solution had 0.9 absorbance units. The culture was centrifuged, and the bacteria re-suspended in physiological saline and incubated at 37 degrees C for 4 h. A monocyte migration bioassay revealed the presence of a single active chemotactic factor in the supernatant from this incubation. The chemotactic factor was concentrated by solid phase chromatography and purified by reverse phase high pressure liquid chromatography. The factor was shown to be indistinguishable from diethyl phthalate (DEP) on the basis of multiple criteria including nuclear magnetic resonance spectroscopy, electron impact mass spectroscopy, UV visible absorption spectrometry, GC and high pressure liquid chromatography retention times, and chemotactic activity toward monocytes. Control experiments with incubated culture media without detectable bacteria did not yield detectable DEP, suggesting it is bacterially derived. It is not known if the bacteria produce diethyl phthalate de novo or if it is a metabolic product of a precursor molecule present in culture media. DEP produced by H. pylori in addition to DEP present in man-made products may contribute to the high levels of DEP metabolites observed in human urine. DEP represents a new class of chemotactic factor.
Collapse
Affiliation(s)
- D A Keire
- CURE: Digestive Diseases Research Center, Veterans Affairs Greater Los Angeles Health Care System, Los Angeles, California 90073, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Larsen ST, Hansen JS, Thygesen P, Begtrup M, Poulsen OM, Nielsen GD. Adjuvant and immuno-suppressive effect of six monophthalates in a subcutaneous injection model with BALB/c mice. Toxicology 2001; 169:37-51. [PMID: 11696408 DOI: 10.1016/s0300-483x(01)00484-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The prevalence of allergic airway diseases is rapidly increasing in Western Europe and North America. This increase in disease prevalence may be associated with environmental pollutants. The present study investigated the adjuvant and immuno-suppressive effect of a series of monophthalates which are considered to be important metabolites of commonly used phthalate plasticizers. The effects were studied in a screening model. Ovalbumin (OA), used as the model antigen, was injected subcutaneously in the neck region of BALB/cJ mice with or without one of the test substances, mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBnP), mono-n-octyl phthalate (MnOP), mono-2-ethylhexyl phthalate (MEHP), mono-iso-nonyl phthalate (MiNP) or mono-iso-decyl phthalate (MiDP). The levels of OA-specific IgE, IgG1 and IgG2a in sera were measured by ELISA. Immuno-suppressive effect, defined as a statistically significant reduction in IgE or IgG1 antibody production, was observed with MEHP (1000 microg/ml, IgE and IgG1), MnOP (1000 microg/ml, IgE and IgG1), MiNP (1000 microg/ml, IgE and 10 microg/ml, IgG1) and MiDP (100 microg/ml, IgE and IgG1). Adjuvant effect, defined as a statistically significant increase in IgE or IgG1 antibody level, occurred with MEHP (10 microg/ml, IgE), MnOP (100 microg/ml, and 10 microg/ml, IgG1) and MiNP (100 microg/ml, IgE). No statistically significant immune modulating effect was seen with MBnP and MnBP.
Collapse
Affiliation(s)
- S T Larsen
- National Institute of Occupational Health, Lersø Parkallé 105, 2100, Copenhagen, Denmark.
| | | | | | | | | | | |
Collapse
|
39
|
Hodgert Jury H, Zacharewski TR, Hammond GL. Interactions between human plasma sex hormone-binding globulin and xenobiotic ligands. J Steroid Biochem Mol Biol 2000; 75:167-76. [PMID: 11226833 DOI: 10.1016/s0960-0760(00)00168-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Human sex hormone-binding globulin (SHBG) binds sex steroids with high affinity. In plasma, the number of SHBG steroid-binding sites far exceeds the molar concentrations of sex steroids, and will accommodate other ligands such as phytoestrogens and fatty acids. We have therefore developed a screening assay to identify ligands for SHBG, which exist in our diet or environment. This assay allows the binding of potential ligands to SHBG to be assessed under physiological conditions, and is sensitive to the effects of plasma constituents. Several classes of endocrine active compounds were tested, including hydroxy-polychlorinated biphenyls (HO-PCBs), phthalate esters, monoesters, chlorinated pesticides, as well as synthetic estrogens and phytoestrogens. The relative binding affinities (RBAs) of various compounds to SHBG were determined in competitive displacement assays, by comparison with 17 beta-estradiol (RBA=100). Synthetic estrogens bound SHBG with RBAs of 0.4 (ethinylestradiol)-0.2 (diethylstilbestrol), while some phytoestrogens bound with RBAs of 0.12 (coumestrol)-0.04 (naringenin). Many compounds did not bind to SHBG with sufficient affinity to allow RBA measurements, and these include: several phytoestrogens, such as genistein and kaempferol, polychlorinated biphenyls, phthalate esters and monoesters. Of nine HO-PCB congeners tested only 4-OH-2', 3', 4', 5'-tetraCB and 4-OH-2, 2', 3', 4', 5'-pentaCB bound SHBG in undiluted serum with RBAs of 0.05 and 0.11. Although all test compounds bound to SHBG with much lower affinity than endogenous sex steroids, these interactions may be physiologically relevant in situations where plasma SHBG levels are high and endogenous sex steroid levels are low, such as in pre-pubertal children and women taking oral contraceptives.
Collapse
Affiliation(s)
- H Hodgert Jury
- Department of Pharmacology and Toxicology, University of Western Ontario, London, Ont., Canada
| | | | | |
Collapse
|
40
|
Blount BC, Milgram KE, Silva MJ, Malek NA, Reidy JA, Needham LL, Brock JW. Quantitative detection of eight phthalate metabolites in human urine using HPLC-APCI-MS/MS. Anal Chem 2000; 72:4127-34. [PMID: 10994974 DOI: 10.1021/ac000422r] [Citation(s) in RCA: 246] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Because of the ubiquity of phthalates and their potential role in increasing risk for cancer and reproductive dysfunction, the need for human exposure assessment studies is urgent. In response to this need, we developed a high-throughput, robust, sensitive, accurate, and precise assay for simultaneous measurement of trace levels of eight phthalate metabolites in human urine by HPLC-MS/MS. Human urine samples were processed using enzymatic deconjugation of the glucuronides followed by solid-phase extraction. The eluate was concentrated, and the phthalate metabolites were chromatographically resolved by reversed-phase HPLC, detected by APCI-tandem mass spectrometry, and quantified by isotope dilution. This selective analytical method permits rapid detection (7.7 min total run time) of eight urinary metabolites of the most commonly used phthalates with detection limits in the low nanagram per milliliter range. Assay precision was improved by incorporating 13C4-labeled internal standards for each of the eight analytes, as well as a conjugated internal standard to monitor deconjugation efficiency. This selective, sensitive, and rapid method will help elucidate potential associations (if any) between human exposure to phthalates and adverse health effects.
Collapse
Affiliation(s)
- B C Blount
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA
| | | | | | | | | | | | | |
Collapse
|
41
|
Maloney EK, Waxman DJ. trans-Activation of PPARalpha and PPARgamma by structurally diverse environmental chemicals. Toxicol Appl Pharmacol 1999; 161:209-18. [PMID: 10581215 DOI: 10.1006/taap.1999.8809] [Citation(s) in RCA: 272] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A large number of industrial chemicals and environmental pollutants, including trichloroethylene (TCE), di(2-ethylhexyl)phthalate (DEHP), perfluorooctanoic acid (PFOA), and various phenoxyacetic acid herbicides, are nongenotoxic rodent hepatocarcinogens whose human health risk is uncertain. Rodent model studies have identified the receptor involved in the hepatotoxic and hepatocarcinogenic actions of these chemicals as peroxisome proliferator-activated receptor alpha (PPARalpha), a nuclear receptor that is highly expressed in liver. Humans exhibit a weak response to these peroxisome proliferator chemicals, which in part results from the relatively low level of PPARalpha expression in human liver. Cell transfection studies were carried out to investigate the interactions of peroxisome proliferator chemicals with PPARalpha, cloned from human and mouse, and with PPARgamma, a PPAR isoform that is highly expressed in multiple human tissues and is an important regulator of physiological processes such as adipogenesis and hematopoiesis. With three environmental chemicals, TCE, perchloroethylene, and DEHP, PPARalpha was found to be activated by metabolites, but not by the parent chemical. A decreased sensitivity of human PPARalpha compared to mouse PPARalpha to trans-activation was observed with some (Wy-14, 643, PFOA), but not other, peroxisome proliferators (TCE metabolites, trichloroacetate and dichloroacetate; and DEHP metabolites, mono[2-ethylhexyl]phthalate and 2-ethylhexanoic acid). Investigation of human and mouse PPARgamma revealed the transcriptional activity of this receptor to be stimulated by mono(2-ethylhexyl)phthalate, a DEHP metabolite that induces developmental and reproductive organ toxicities in rodents. This finding suggests that PPARgamma, which is highly expressed in human adipose tissue, where many lipophilic foreign chemicals tend to accumulate, as well as in colon, heart, liver, testis, spleen, and hematopoietic cells, may be a heretofore unrecognized target in human cells for a subset of industrial and environmental chemicals of the peroxisome proliferator class.
Collapse
Affiliation(s)
- E K Maloney
- Division of Cell and Molecular Biology, Boston University, Boston, Massachusetts, 02215, USA
| | | |
Collapse
|
42
|
Snyder EL, Aster RH, Heaton A, Grode G, Napychank P, Kagen L, Jefferies LC, Hedberg S, Buchholz DH. Five-day storage of platelets in a non-diethylhexyl phthalate-plasticized container. Transfusion 1992; 32:736-41. [PMID: 1412680 DOI: 10.1046/j.1537-2995.1992.32893032101.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A non-diethylhexyl phthalate (DEHP)-plasticized blood bag for 5-day storage of random-donor platelet concentrates has been developed. The plastic bag is composed of polyvinylchloride plastic with a butyryl trihexyl citrate plasticizer. The suitability of this plastic for the storage of platelet concentrates for use in clinical transfusion practice was evaluated. In vitro storage studies showed no significant differences at Day 5 for a series of in vitro assays (test plastic vs. control plastic) including pH (7.31 vs. 7.44), lactate dehydrogenase discharge (21.8 vs. 17.1%), pO2 (103 vs. 120 torr), osmotic recovery (52 vs. 57%), and morphology score (527 vs. 516). For paired radiolabeled recovery and survival data from autologous blood donors, results showed equivalence between the test plastic and two control plastics. A small but significant difference between test and control plastics in regard to survival was found by using a linear computer model, but not with a gamma function (multiple-hit) model. For paired transfusions to thrombocytopenic patients, the corrected count increments at 1 to 4 hours (test vs. control) were 13,534 versus 15,494 (p > 0.05, NS). Similar results were seen for corrected count increments determined at 12 to 24 hours. It can be concluded that platelets stored in the test plastic are acceptable for use in clinical practice.
Collapse
Affiliation(s)
- E L Snyder
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Granholm T, Creasy DM, Pöllänen P, Söder O. Di-n-pentyl phthalate-induced inflammatory changes in the rat testis are accompanied by local production of a novel lymphocyte activating factor. J Reprod Immunol 1992; 21:1-14. [PMID: 1734074 DOI: 10.1016/0165-0378(92)90036-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Phthalate esters (PAE) are plasticizers in polyvinyl chloride plastics used, for example, in package material for medical solutions. PAE exposure is associated with testicular damage that primarily affects Sertoli cells, and is concomitant with leukocyte infiltration into the testicular interstitium. We have demonstrated that the rat testis constitutively produces a lymphocyte activating factor (LAF) resembling interleukin-1 alpha, and originating from Sertoli cells. The testicular interleukin-1-like factor (tIL-1) has a relative molecular mass (Mr) of 17,000 (17 k) and an isoelectric point (pI) of 5.7. In the present study we have measured testicular LAF activity after exposure to di-n-pentyl phthalate (DPP) in 40-day-old rats. We found a large increase in LAF bioactivity which was evident already 3 h after a single oral dose of DPP. The increase was maximal 9-12 h after exposure, and had decreased toward the control level at 24 h. The increased activity was found to be at least partly due to the induction of a novel LAF with Mr 38,000 and pI 4.5. Morphological examination confirmed earlier results with an interstitial leukocyte infiltration 6 h after DPP exposure. The identity of the novel LAF and its functional relation to testicular inflammation remain to be established.
Collapse
Affiliation(s)
- T Granholm
- Pediatric Endocrinology Unit, Karolinska Hospital, Stockholm, Sweden
| | | | | | | |
Collapse
|
44
|
Seidl S, Gosda W, Reppucci AJ. The in vitro and in vivo evaluation of whole blood and red cell concentrates drawn on CPDA-1 and stored in a non-DEHP plasticized PVC container. Vox Sang 1991; 61:8-13. [PMID: 1949719 DOI: 10.1111/j.1423-0410.1991.tb00919.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A new polyvinyl chloride (PVC) blood storage container, PL 2209, plasticized with butyryl-n-trihexyl-citrate (BTHC) instead of diethylhexyl phthalate (DEHP) was used for in vitro and in vivo studies. Whole blood and red cell concentrates drawn on CPDA-1 were stored 42 days at 1-6 degrees C. Various biochemical parameters were tested and compared to those values seen in the literature for products stored in DEHP-plasticized containers. Measurements of lactate production, glucose consumption, sodium and potassium ions for both whole blood and red cells were compatible with published data. Adenosine triphosphate (ATP) values were on the average 73% for the red cell units and 80% for the whole blood units after 35 days storage. Hemolysis was 0.43% for the red cell concentrate and 0.38% for the whole blood units after the same storage period. Autologous recovery studies after 35 days of storage for both the whole blood units and red cell concentrate gave 80% recovery 24 h after reinjection. From these data it can be concluded that PL 2209 BTHC-plasticized PVC blood storage containers allow 35 days storage of blood draw on CPDA-1 and can be considered as an alternative to DEHP-plasticized PVC containers.
Collapse
Affiliation(s)
- S Seidl
- Department of Immunohaematology, University Frankfurt/Main, FRG
| | | | | |
Collapse
|
45
|
Bird AC. Doyne Lecture. Pathogenesis of retinal pigment epithelial detachment in the elderly; the relevance of Bruch's membrane change. Eye (Lond) 1991; 5 ( Pt 1):1-12. [PMID: 2060656 DOI: 10.1038/eye.1991.2] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- A C Bird
- Department of Clinical Ophthalmology, Moorfields Eye Hospital, London
| |
Collapse
|
46
|
Chapin R, Phelps J. Recent advances in testicular cell culture: Implications for toxicology. Toxicol In Vitro 1990; 4:543-59. [DOI: 10.1016/0887-2333(90)90115-a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|