Muscarinic receptors mediate the endocrine‐disrupting effects of an organophosphorus insecticide in zebrafish

• Published in: Environmental toxicology Vol. 32; no. 7; pp. 1964 - 1972
• Main Authors: Santos da Rosa, João Gabriel, Alcântara Barcellos, Heloísa Helena de, Fagundes, Michele, Variani, Cristiane, Rossini, Mainara, Kalichak, Fabiana, Koakoski, Gessi, Acosta Oliveira, Thiago, Idalencio, Renan, Frandoloso, Rafael, Piato, Angelo L., José Gil Barcellos, Leonardo
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01-07-2017
• Subjects: acetylcholine receptors; Acetylcholine receptors (muscarinic); Agrochemicals; Animals; Aquatic ecosystems; Chemical compounds; Cortisol; Danio rerio; Ecosystems; Endocrine disruptors; Endocrine Disruptors - toxicity; Freshwater fishes; Gene expression; Genes; Glucocorticoids; Homeostasis; Hormones; Hsp70 protein; HSP72 Heat-Shock Proteins - genetics; HSP72 Heat-Shock Proteins - metabolism; Hydrocortisone - metabolism; Hypothalamus; Insecticides; Insecticides - toxicity; Locomotion - drug effects; Methyl Parathion - toxicity; methyl‐parathion; Muscarinic Antagonists - pharmacology; Pesticides; Phosphoproteins - genetics; Phosphoproteins - metabolism; Pituitary; Pollutants; Pro-Opiomelanocortin - genetics; Pro-Opiomelanocortin - metabolism; Proto-Oncogene Proteins c-fos - metabolism; Receptors; Receptors, Muscarinic - metabolism; RNA, Messenger - metabolism; Scopolamine; Scopolamine - pharmacology; Steroidogenesis; Structure-function relationships; Water Pollutants, Chemical - toxicity; Zebrafish; Zebrafish - metabolism; Zebrafish Proteins - genetics; Zebrafish Proteins - metabolism; acetylcholine receptors; steroidogenesis; methyl-parathion; scopolamine; Danio rerio
• ISSN: 1520-4081; 1522-7278
• DOI: 10.1002/tox.22424

The glucocorticoid cortisol, the end product of hypothalamus‐pituitary‐interrenal axis in zebrafish (Danio rerio), is synthesized via steroidogenesis and promotes important physiological regulations in response to a stressor. The failure of this axis leads to inability to cope with environmental challenges preventing adaptive processes in order to restore homeostasis. Pesticides and agrichemicals are widely used, and may constitute an important class of environmental pollutants when reach aquatic ecosystems and nontarget species. These chemical compounds may disrupt hypothalamus‐pituitary‐interrenal axis by altering synthesis, structure or function of its constituents. We present evidence that organophosphorus exposure disrupts stress response by altering the expression of key genes of the neural steroidogenesis, causing downregulation of star, hsp70, and pomc genes. This appears to be mediated via muscarinic receptors, since the muscarinic antagonist scopolamine blocked these effects.