Effects of acute arsenic exposure in two different populations of Hyalella curvispina amphipods from North Patagonia Argentina

ABSTRACT

Arsenic (As) is a toxic metalloid present in high levels in diverse regions of Argentina. The aim of this study was to determine acute As-mediated toxicity in two different populations of autochthonous Hyalella curvispina amphipods from a reference site (LB) and an agricultural one (FO) within North Patagonia Argentina. Previously, both populations exhibited significant differences in pesticide susceptibility. Lab assays were performed to determine acute lethal concentrations, as well as some biochemical parameters. Lethal concentration (LC₅₀) values obtained after 48 and 96 hr As exposure were not significantly different between these populations, although FO amphipods appeared slightly less susceptible. LC₅₀-48 hr values were 3.33 and 3.92 mg/L As, while LC₅₀-96 hr values were 1.76 and 2.14 mg/L As for LB and FO amphipods. The no observed effect concentration (NOEC) values were 0.5 mg/L As. Cholinesterase (ChE) activity was significantly diminished by As acute exposure (0.5–1.5 mg/L As), indicative of a significant neurotoxic action for this metalloid in both amphipod populations. Activities of catalase (CAT) and glutathione S-transferase (GST) and levels of reduced glutathione (GSH) were differentially altered following As exposure. CAT activity was increased after 96 hr As exposure. GST activity and GSH levels were significantly elevated followed by either a decrease or a return to control values after 96 hr treatment. However, additional studies are necessary to understand the mechanisms underlying the As-mediated oxidative effects in H. curvispina. Our findings suggest that measurement of ChE activity in H. curvispina amphipods might serve as a useful biomarker of As exposure and effect.

KEYWORDS:

• Arsenic toxicity
• Hyalella curvispina
• cholinesterase
• antioxidant enzymes
• GSH content

Acknowledgments

This work was supported by grants from the National University of Comahue (PIN 04/N025-2015/2019 and PIN 04/N037-2020/2022) and from National Council for Scientific and Technological Research, CONICET, (PIP 0239-2016/2020 and PUE 0067-2017-2021). The authors thank Ms. Luciana Di Pascuale from MED, Mundis Medical English Program, Argentina, for proofreading the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the CONICET [PIP 0239-2016/2020, PUE 0067-2017-2021]; Universidad Nacional del Comahue [PIN 04/N025-2015/2019, PIN 04/N037-2020/2022].