Decrease in Aryl Hydrocarbon Receptor and 17β-Estradiol Receptor (A&B) Gene Expression in The Hypothalamus and The Pineal Gland, After Administration of Dimethylbenz (A) Anthracene, A Mammary Carcinogen, To Sprague-Dawley Female Rats.
Thomas Cadoudal,Véronique Lenoir,Graziella Penot,Indika Sh Sathish,Yueqin Zhao,Xavier Coumoul,Claude Forest,Bernard Kerdelhué +7 more
TL;DR: DMBA reduces the brain expression of AHR, ERS1 and ERS2, key transcriptional factors, but only in brain structures involved in the control of neuroendocrine systems.
read more
Abstract: Purpose: The promotion of mammary adenocarcinoma induced by Dimethyl benz (a) Anthracene (DMBA) is preceded by disruptions of the Hypothalamo-Pituitary-Gonadal and Hypothalamo-Pituitary-Adrenal axes and by a reduction of the secretion of Melatonin. We hypothesized that these disruptions might be induced by changes, in neuroendocrine structures of the brain, in the gene expression of receptors for Aryl Hydrocarbon (AHR) and 17β-Estradiol (ERS1 and ERS2).
Methods: Sprague Dawley female rats received one single administration of DMBA (75 mg/kg) at 52-55 days of age and were ovariectomized 5 days later. Then, one month later, RNAs from the Pineal Gland, the Hippocampus and the Hypothalamus were prepared and analyzed by real-time PCR for the presence of the transcripts encoding receptors for AHR and 17β-Estradiol (ERS1 and ERS2) together with those encoding Gonadotropin Releasing Hormone (GNRH1),Corticotropin Releasing Hormone (CRH) and Hydroxy-Indol-O-Methyl-Transferase (ASMT),the rate limiting enzyme for the synthesis of Melatonin.
Results: There was a long lasting and almost identical decrease in the expression of AHR, ERS1 and ERS2 in the Hypothalamus and the Pineal Gland. Also, there was an increase in the expression of ASMT and GNRH1 genes in the Pineal Gland, and of the GNRH1 gene in the Hypothalamus.However and, very interestingly, no effect was seen for the expression of any investigated gene in the Hippocampus, a structure of the brain implicated in cognition.
Conclusion: DMBA reduces the brain expression of AHR, ERS1 and ERS2, key transcriptional factors, but only in brain structures involved in the control of neuroendocrine systems.
read more
Chat with Paper
AI Agents for this Paper
Find similar papers on Google Scholar, PubMed and Arxiv
Write a critical review of this paper
Analyze citations of this paper to find unaddressed research gaps
Citations
Dimethyl-Benz(a)anthracene: A mammary carcinogen and a neuroendocrine disruptor.
TL;DR: The present review analyses the various neuroendocrine disruptions that occur along the HPG and the HPA axes, and the marked inhibitory effect of the carcinogen on melatonin secretion.
50
Polycystic Ovarian Syndrome: A Review
Ankita Veerbhan
- 01 Jan 2016
TL;DR: Signs and indications of PCOS incude no menstrual periods, substantial periods, abundance body and facial hair, skin inflammation, pelvic torment, trouble getting pregnant, and patches of thick, darker, smooth skin.
4
References
Modulation of oestrogen receptor signalling by association with the activated dioxin receptor.
Fumiaki Ohtake,Ken-ichi Takeyama,Takahiro Matsumoto,Hirochika Kitagawa,Yasuji Yamamoto,Keiko Nohara,Chiharu Tohyama,Andrée Krust,Junsei Mimura,Pierre Chambon,Junn Yanagisawa,Yoshiaki Fujii-Kuriyama,Shigeaki Kato +12 more
TL;DR: It is shown that the agonist-activated AhR/Arnt heterodimer directly associates with oestrogen receptors ER-α and ER-β, which results in the recruitment of unliganded ER and the co-activator p300 to ostrogen-responsive gene promoters, leading to activation of transcription and oestrogensic effects.
818
Differentiation of the mammary gland and susceptibility to carcinogenesis
TL;DR: Induction of mammary cancer in rats by administration of the chemical carcinogen 7, 12-dimethylbenz(a)anthracene reveals that the same factors influencing human breast cancer risk also affect the susceptibility of the rat mammary gland to the chemicalcar carcinogen.
647
Cytochrome P450-mediated metabolism of estrogens and its regulation in human
TL;DR: A novel finding that human CYP1B1 is regulated by estradiol via the estrogen receptor suggests that the regulation of CYP enzymes involved in estrogen metabolism by estrogen itself would be physiologically significant for the homeostasis of estrogens at local organs.
589
Dioxin receptor is a ligand-dependent E3 ubiquitin ligase
Fumiaki Ohtake,Atsushi Baba,Ichiro Takada,Maiko Okada,Kei Iwasaki,Hiromi Miki,Sayuri Takahashi,Alexander Kouzmenko,Keiko Nohara,Tomoki Chiba,Yoshiaki Fujii-Kuriyama,Shigeaki Kato +11 more
TL;DR: The findings uncover a function for AhR as an atypical component of the ubiquitin ligase complex and demonstrate a non-genomic signalling pathway in which fat-soluble ligands regulate target-protein-selective degradation through a ubiquitIn ligasecomplex.
584
Endocrine disrupters: a review of some sources, effects, and mechanisms of actions on behaviour and neuroendocrine systems
Cheryl A. Frye,E Bo,Gemma Calamandrei,Laura Calzà,Francesco Dessì-Fulgheri,Mercedes Fernandez,Leonida Fusani,Olivier Kah,Małgorzata Kajta,Y Le Page,Heather B. Patisaul,Aldina Venerosi,Anna Wójtowicz,Giancarlo Panzica +13 more
TL;DR: EDCs, from varied sources, may have organisational effects during development and/or activational effects in adulthood that influence sexually‐dimorphic, reproductively‐relevant processes or other functions, by mimicking, antagonising or altering steroidal actions.