Examining the subchronic (28-day) effects of aqueous Cd-BaP co-exposure on detoxification capacity and cardiac function in adult zebrafish (Danio rerio)

Vladimir Kodzhahinchev; Mahesh Rachamalla; Ahmad Al-Dissi; Som Niyogi; Lynn P Weber

doi:10.1016/j.aquatox.2023.106672

Examining the subchronic (28-day) effects of aqueous Cd-BaP co-exposure on detoxification capacity and cardiac function in adult zebrafish (Danio rerio)

Aquat Toxicol. 2023 Oct:263:106672. doi: 10.1016/j.aquatox.2023.106672. Epub 2023 Aug 27.

Authors

Vladimir Kodzhahinchev¹, Mahesh Rachamalla², Ahmad Al-Dissi³, Som Niyogi⁴, Lynn P Weber⁵

Affiliations

¹ Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada. Electronic address: Vladimir.kod@usask.ca.
² Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada.
³ Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada.
⁴ Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada.
⁵ Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada.

PMID: 37672889
DOI: 10.1016/j.aquatox.2023.106672

Abstract

The present study aimed to examine the effects of environmentally relevant concentrations of cadmium (Cd) and Benzo[a]Pyrene (BaP) in the adult zebrafish (Danio rerio). To this end, fish were exposed to either 1 or 10 μg/L Cd or 0.1 or 1 μg/L BaP in isolation, or a co-exposure containing a mixture of the two toxicants. Our results showed extensive modulation of the expression of key antioxidant genes (GPx, SOD1, catalase), detoxifying genes (MT1, MT2, CYP1A1) and a stress biomarker (HSP70) differing between control, single toxicant groups and co-exposure groups. We additionally carried out histopathological analysis of the gills, liver, and hearts of exposed animals, noting no differences in tissue necrosis or apoptosis. Finally, we carried out ultrasonographic analysis of cardiac function, noting a significant decrease of E-wave peak velocity and end diastolic volume in exposed fish. This in turn was accompanied by a decrease in stroke volume and ejection fraction, but not cardiac output in co-exposed fish. The present study is the first to demonstrate that a subchronic aqueous exposure to a Cd-BaP mixture can extensively modulate detoxification capacity and cardiac function in adult zebrafish in a tissue-specific manner.

Keywords: Cardiotoxicity, Aquatic toxicology; Gene expression; Metal; Mixture toxicity; PAH.