Effects of carbamazepine, a contaminant of emerging concern, on the physiology of Astyanax lacustris mature females

Abstract

The presence of contaminants of emerging concern, such as the drug carbamazepine (CBZ), in aquatic ecosystems has attracted attention. Due to its persistence and low elimination rates, toxic effects to aquatic organisms, may be generated, including impairment of physiological processes. Among the effects of CBZ, disruption of the reproductive physiology of male organism has already been demonstrated, however, information about those effects in females is still lacking. Through in vivo and in vitro approaches and three environmentally relevant concentrations of CBZ (30 ng L-1, 300 ng L-1 and 3000 ng L-1), this study aims to evaluate CBZ effects on reproductive, metabolic and nervous system, and those related to xenobiotic biotransformation in sexually mature Astyanax lacustris females. In the in vivo assay, females will be exposed for 14 days to CBZ and then, the following hypotheses will be tested: 1) CBZ will promote alterations in the reproductive physiology of females, when analyzing the plasma level of steroid hormones and the ovarian morphology; 2) this exposure will alter the concentration of energetic substrates in storage tissues; 3) this exposure will change the activity of enzymes involved in antioxidant defenses in the brain and in the ovarian; and will also 4) affect the expression of aromatase gene and the activity of acetylcholinesterase in the brain. In order to understand the toxicological effects of CBZ in the steroidogenesis and the biotransformation process, in vitro assays will be conducted with the ovaries and the liver, with the following hypothesis 1) CBZ will promote changes in steroidogenesis and gametogenesis in the ovaries; and 2) CBZ will alter the transcription of biotransformation hepatic enzymes. In general, this study will provide more information about the toxicity and action mechanism of CBZ in A. lacustris females. (AU)