Evaluation of the effects of environmentally relevant concentrations of carbamazepine on the neuroendocrine regulation of Astyanax lacustris males (Teleostei: Characiformes).

• Grant number: 23/03227-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2023
• End date: July 31, 2025
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Renata Guimarães Moreira Whitton
• Grantee: Daniel Jaen Alonso Neto
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 24/05369-7 - Assessing the Health Impacts of Environmental-Relevant Concentrations of Carbamazepine in Danio rerio, BE.EP.MS

Abstract

The homeostasis of the neuroendocrine system in vertebrates depends on the interaction between the hypothalamus and the pituitary gland, and the hypothalamic-pituitary-gonadal (HPG), thyroid (HPT), and interrenal (HPI) axes communicate within them to regulate functions such as reproduction, metabolism, and stress response. This interaction between the hypothalamus and pituitary in neuroendocrine regulation has been extensively studied in teleosts, but mainly in temperate species. As in vertebrates, in teleosts, hypothalamic neurons produce neuro-hormones that stimulate or inhibit the release of pituitary hormones, which in turn regulate the synthesis and release of gonadal and interenal steroids and thyroid hormones. Environmental changes, such as the presence of chemical compounds in the water can modulate the neuroendocrine regulation of these axes. Currently, many chemical compounds are released into the environment, acting as endocrine disruptors (ED). Among these compounds, we highlight carbamazepine (CBZ), a pharmaceutical used to treat neurological disorders, and frequently found in aquatic environments. The CBZ is highly resistant to biodegradation, which may result in a high potential for bioaccumulation and physiological interference in teleosts, and therefore deserves attention in studies of ED in aquatic organisms. The goal of this project is to evaluate the ability of CBZ to act as an ED in the HPG, HPT and HPI axes in males of the native teleost Astyanax lacustris. The fish will be sub chronically exposed to environmentally relevant concentrations of CBZ and analyzed the plasma concentrations of the gonadal steroids (17²-estradiol, testosterone and 11-ketotestosterone), cortisol, and thyroid hormones (T3 and T4). It will be also analyzed the pituitary gene expression of adrenocorticotropic hormone (acth), thyroid-stimulating hormone (tsh), follicle-stimulating hormone (fsh) and luteinizing hormone (lh).