Highlights
- Both SA and Cd induce oxidative stress and boost LPO in tongue sole.
- SA amplifies oxidative stress and intensifies LPO in fish by interacting with Cd.
- Antioxidants exhibit a higher sensitivity to SA compared to Cd exposure.
- Escalating levels of stressors enhance the integrated antioxidant response.
- Sensitive biomarkers for oxidant stress by SA and Cd exposure are identified.
Abstract
Antioxidant responses of juvenile sole exposed to seawater acidification (SA) and Cd were investigated. SA increased lipid peroxidation (LPO) in the fish, independent of Cd concentrations. Cd at medium and high levels inflated LPO under no or moderate SA conditions. This effect was absent under high SA levels, due to SA effect exceeding and obscuring Cd effect. SA and Cd collaborated to provoke LPO, with SOD and CAT being stimulated to defend against oxidative stress, while those related to GSH redox cycle were inhibited under SA exposure. Responses of GSH-related antioxidants to Cd impact varied contingent on their interactions with SA. This defensive strategy was insufficient to protect fish from increased LPO. Antioxidants responded more sensitively to SA than Cd exposure. GSH, GR, SOD and CAT are sensitive biomarkers for SA conditions. The findings offer insights into assessing fish’s antioxidant defense strategy under Cd and SA circumstances in natural habitats.
Ni Z., Liu J., Cui W., Cao L. & Dou S., 2024. Interactive impacts of CO2-induced seawater acidification and cadmium exposure on antioxidant defenses of juvenile tongue sole Cynoglossus semilaevis. Marine Pollution Bulletin 201: 116284. doi: 10.1016/j.marpolbul.2024.116284. Article (subscription required).
