Assessing the consequences of the pesticide methoxychlor: neuroendocrine and behavioral measures as indicators of biological impact of an estrogenic environmental chemical

Ottinger, Mary Ann; Wu, Julie M.; Hazelton, Julie L.; Abdelnabi, Mahmoud; Thompson, Nichola; Quinn, Michael J.; Donoghue, Dan; Schenck, Frank J; Ruscio, Michael; Beavers, J.; Jaber, Mark

doi:10.1016/j.brainresbull.2004.11.019

Cited by 36 publications

(18 citation statements)

References 39 publications

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“…It has been well established that many environmental chemicals are maternally deposited into eggs [36][37][38][39]. However, despite the aryl hydrocarbon receptor (AhR) activity and TEQ of PCB 77, no adverse effects had been observed on embryonic survival in treated or environmentally exposed tree swallows.…”

Section: Exposure To Pcb 77 Did Not Affect Survivabilitymentioning

confidence: 99%

Effects of in ovo exposure to 3,3′,4,4′‐tetrachlorobiphenyl (PCB 77) on heart development in tree swallow (Tachycineta bicolor)

Carro

Walker

Dean

et al. 2017

Enviro Toxic and Chemistry

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Tree swallow (Tachycineta bicolor) eggs from 2 uncontaminated sites, the Patuxent Research Refuge (Laurel, MD, USA) and the Cobleskill Reservoir (Cobleskill, NY, USA) were dosed with polychlorinated biphenyl (PCB) 77 to evaluate effects on the developing cardiovascular system. To ensure embryonic viability, treatments were administered into the air cell at embryonic day 2.5 including: untreated (control), vehicle (filtered sterilized fatty acid mixture), 100 ng/g and 1000 ng/g egg. Eggs were dosed in the field with 0.2 mL/egg, returned to the nest, collected at embryonic day 13, hatched in the laboratory, and necropsied. The PCB 77-treated hatchlings were compared with uninjected, vehicle-injected, and environmentally exposed hatchlings collected from a PCB-contaminated Upper Hudson River (NY, USA) site. The PCB 77-treated embryos showed no effects on hatching success or hatchling mortality, heart index, or morphological measures of 4 distinct heart layers (heart width, length, septal thickness, total and ventricular cavity area) compared with controls. Hatchlings that had received PCB 77 exhibited increased incidence of a cardiomyopathy and absence of the ventricular heart wall compact layer (Chi square test; p < 0.001); environmentally exposed embryos showed no apparent effects. The compact layer is essential in development and overall heart function for ventricular cardiomyocyte proliferation and normal heart contraction. The finding that in ovo exposure to PCB 77 resulted in distinct cardiomyopathy has implications for long-term individual fitness. Environ Toxicol Chem 2018;37:116-125. C 2017 SETAC

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Section: Exposure To Pcb 77 Did Not Affect Survivabilitymentioning

confidence: 99%

Effects of in ovo exposure to 3,3′,4,4′‐tetrachlorobiphenyl (PCB 77) on heart development in tree swallow (Tachycineta bicolor)

Carro

Walker

Dean

et al. 2017

Enviro Toxic and Chemistry

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“…Nevertheless, specific evidence for endocrine disruption of GnRH neurons in birds is largely lacking. It is likely that this is the case, as EDCs affect neurotransmitter systems in birds that are known to affect GnRH cells (see Ottinger et al (2005b) for a review). Future research will be very important in determining specific effects of EDCs on avian GnRH cells.…”

Section: Birdsmentioning

confidence: 98%

Environmental Endocrine Disruption of Brain and Behavior

Gore¹,

Crews

2009

Hormones, Brain and Behavior

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“…Recent studies have demonstrated that the estrogenic activity of MXC provides evidence for EDC action in many tissues including the uterus, vagina, brain and bone (35). MXC can bind to ERα and ERβ, which suggest that MXC may be associated with E2-mediated responses in humans (36).…”

Section: Effects Of E2 Bpa or MXC On Cyclin D1 And P21 Expression Inmentioning

confidence: 99%

Treatment with bisphenol A and methoxychlor results in the growth of human breast cancer cells and alteration of the expression of cell cycle-related genes, cyclin D1 and p21, via an estrogen receptor-dependent signaling pathway

Choi

2012

Int J Mol Med

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Abstract. Various endocrine disrupting chemicals (EDCs) are exogenous compounds found in the environment and have the potential to interfere with the endocrine system and hormonal regulation. Among EDCs, bisphenol A (BPA) and 1,1,1-trichloro-2,2-bis(4-methoxyphenol)-ethane [methoxychlor (MXC)] have estrogenic activity resulting in a variety of dysfunctions in the E2-mediated response by binding to estrogen receptors (ERs), causing human health problems such as abnormal reproduction and carcinogenesis. In this study, we investigated the effects of BPA and MXC on cell proliferation facilitated by ER signaling in human breast cancer cells. MCF-7 cells are known to be ERα-positive and to be a highly E2-responsive cancer cell line; these cells are, therefore, a useful in vitro model for detecting estrogenic activity in response to EDCs. We evaluated cancer cell proliferation following BPA and MXC treatment using an MTT assay. We analyzed alterations in the expression of genes associated with the cell cycle in MCF-7 cells by semi-quantitative reverse-transcription PCR following treatment with BPA or MXC compared to EtOH. To determine whether BPA and MXC stimulate cancer cell growth though ER signaling, we co-treated the cells with agonists (propyl pyrazoletriol, PPT; and diarylpropionitrile, DPN) or an antagonist (ICI 182,780) of ER signaling and reduced ERα gene expression via siRNA in MCF-7 cells before treatment with EDCs. These studies confirmed the carcinogenicity of EDCs in vitro. As a result, BPA and MXC induced the cancer cell proliferation by the upregulation of genes that promote the cell cycle and the downregulation of anti-proliferative genes, especially ones affecting the G1/S transition via ERα signaling. These collective results confirm the carcinogenicity of these EDCs in vitro. Further studies are required to determine whether EDCs promote carcinogenesis in vivo.

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Assessing the consequences of the pesticide methoxychlor: neuroendocrine and behavioral measures as indicators of biological impact of an estrogenic environmental chemical

Cited by 36 publications

References 39 publications

Effects of in ovo exposure to 3,3′,4,4′‐tetrachlorobiphenyl (PCB 77) on heart development in tree swallow (Tachycineta bicolor)

Effects of in ovo exposure to 3,3′,4,4′‐tetrachlorobiphenyl (PCB 77) on heart development in tree swallow (Tachycineta bicolor)

Environmental Endocrine Disruption of Brain and Behavior

Treatment with bisphenol A and methoxychlor results in the growth of human breast cancer cells and alteration of the expression of cell cycle-related genes, cyclin D1 and p21, via an estrogen receptor-dependent signaling pathway

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