Influence of the combination of carbamazepine and increased temperature on the reproductive physiology of Astyanax lacustris males (Teleostei: Characiformes).

• Grant number: 25/06100-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2025
• End date: September 30, 2027
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Renata Guimarães Moreira Whitton
• Grantee: Rayanne Alves dos Santos
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 24/13478-0 - Faunal responses to anthropogenic environmental changes: contributions of conservation physiology, AP.TEM

Abstract

Increased anthropogenic activity leads to the release of several harmful substances into ecosystems. As a result, global warming intensifies, increasing water temperature, which can be detrimental to teleost, including their reproductive success. Not only that, but the presence of pharmaceuticals in aquatic ecosystems makes it difficult for them to survive and reproduce in an adverse environment. Among the most widely used pharmaceuticals, carbamazepine (CBZ) stands out, an anticonvulsant that can cause changes in the reproductive physiology of fish. When combined with elevated temperatures, the toxicity of pharmaceuticals, including CBZ, can be increased, causing even more toxic effects. Considering that little is known about this interaction of factors (temperature and CBZ) on teleost, including native species, the present study aims to evaluate the influence of temperature on the toxicity of CBZ in different aspects of the neuroendocrine control of reproduction of Astyanax lacustris males. Fish will be exposed for 7 days to two concentrations of CBZ: 5 ug/L and 10 ug/L and two different temperatures: control 24 ºC ± 2 ºC and elevated 32 ºC ± 2 ºC, this simulating a global warming scenario. The mRNA levels of gnrh in the hypothalamus, fsh¿ and lh¿ in the pituitary and hsp70 in the gills and liver of the animals will be evaluated, as well as the plasma level of steroid hormones (cortisol, testosterone, 11-ketotestosterone and 17¿-estradiol). The results obtained will contribute to the knowledge of the possible effects caused by the toxicity of CBZ together with the exponential growth of climate change. (AU)