1. The Aryl hydrocarbon receptor mediates reproductive toxicity of polychlorinated biphenyl congener 126 in rats.
- Author
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Klenov V, Flor S, Ganesan S, Adur M, Eti N, Iqbal K, Soares MJ, Ludewig G, Ross JW, Robertson LW, and Keating AF
- Subjects
- Animals, Basic Helix-Loop-Helix Transcription Factors genetics, Biotransformation genetics, Body Weight drug effects, Female, Gene Expression Regulation drug effects, Hormones blood, Organ Size drug effects, Ovary drug effects, Ovary metabolism, Ovary pathology, RNA, Messenger metabolism, Rats, Sprague-Dawley, Rats, Transgenic, Receptors, Aryl Hydrocarbon genetics, Reproduction drug effects, Uterus drug effects, Uterus metabolism, Uterus pathology, Rats, Basic Helix-Loop-Helix Transcription Factors deficiency, Endocrine Disruptors toxicity, Polychlorinated Biphenyls toxicity, Receptors, Aryl Hydrocarbon deficiency
- Abstract
Polychlorinated biphenyls (PCBs) are endocrine disrupting chemicals with documented, though mechanistically ill-defined, reproductive toxicity. The toxicity of dioxin-like PCBs, such as PCB126, is mediated via the aryl hydrocarbon receptor (AHR) in non-ovarian tissues. The goal of this study was to examine the uterine and ovarian effects of PCB126 and test the hypothesis that the AHR is required for PCB126-induced reproductive toxicity. Female Holzman-Sprague Dawley wild type (n = 14; WT) and Ahr knock out (n = 11; AHR
-/- ) rats received a single intraperitoneal injection of either corn oil vehicle (5 ml/kg: WT_O and AHR-/- _O) or PCB126 (1.63 mg/kg in corn oil: WT_PCB and AHR-/- _PCB) at four weeks of age. The estrous cycle was synchronized and ovary and uterus were collected 28 days after exposure. In WT rats, PCB126 exposure reduced (P < 0.05) body and ovary weight, uterine gland number, uterine area, progesterone, 17β-estradiol and anti-Müllerian hormone level, secondary and antral follicle and corpora lutea number but follicle stimulating hormone level increased (P < 0.05). In AHR-/- rats, PCB126 exposure increased (P ≤ 0.05) circulating luteinizing hormone level. Ovarian or uterine mRNA abundance of biotransformation, and inflammation genes were altered (P < 0.05) in WT rats due to PCB126 exposure. In AHR-/- rats, the transcriptional effects of PCB126 were restricted to reductions (P < 0.05) in three inflammatory genes. These findings support a functional role for AHR in the female reproductive tract, illustrate AHR's requirement in PCB126-induced reprotoxicity, and highlight the potential risk of dioxin-like compounds on female reproduction., (Copyright © 2021. Published by Elsevier Inc.)- Published
- 2021
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