Impacts of acute Fipronil exposure on cardiorespiratory function of the rainbow trout (Oncorhynchus mykiss) during aerobic exercise

• Grant number: 23/01330-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: August 01, 2023
• End date: July 26, 2024
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Luiz Henrique Florindo
• Grantee: Igor Noll Guagnoni
• Supervisor: Tobias Wang
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil
• Institution abroad: Aarhus University, Denmark
• Associated to the scholarship: 20/14167-8 - Effects of the insecticide Fipronil on the short-term regulation of the cardiorespiratory function in neotropical fish Hoplias malabaricus, the Traíra, BP.DR

Abstract

Fipronil is a chloride channel antagonist regulated by gamma-aminobutyric acid (GABA) or glutamic acid, which causes the death of arthropods by impediment neuronal repolarization associated with the blockade of the influx of chloride into cells. Because of its low resistance potential, high selective toxicity to arthropods, and long persistence in the environment, fipronil is one of the most widely commercialized pesticides in the world. However, toxicological studies have shown that fipronil displays high toxicity to several nontarget aquatic organisms such as fish. Many studies reported that fish contamination by Fipronil promotes gill damage and tissue protection responses with major consequences for fitness, such as the direct impact on cardiorespiratory efficiency, gas exchange capacity, and acid-base regulation. Also, although vertebrates do not have chloride channels regulated by glutamic acid, these animals have chloride channels regulated by GABA, and consequently are also susceptible to the effects of Fipronil. Many studies have found GABA receptors in central and peripheral neural sites of vertebrates associated with the respiratory rhythm generator, baroreflex and chemoreflex control, and the control of basal cardiorespiratory function. All these regulatory mechanisms play an important role in the efficiency of O2 extraction and transport and are also essential for the sustainable production of the energy required to perform activities related to the adaptive value of animals. So, considering that: (1) Fipronil is widely used around the world and frequently found in water; (2) the vertebrates' neural pathways involved in cardiovascular and respiratory control are highly conserved; (3) and recent studies have shown a strong influence of GABA receptors on the basal cardiorespiratory function of ectothermic vertebrates, this project will test if acute Fipronil contamination can impact the capacity of rainbow trout (Oncorhynchus mykiss) to sustain aerobic exercise through important dysfunctions in the regulatory mechanisms of cardiorespiratory function. (AU)