Protective Roles of Calcium Channel Blocker Against Cadmium-Induced Physiological Stress in Freshwater Teleost Oncorhynchus mykiss

摘要

The roles of verapamil (VRP), a calcium channel blocker, on cadmium-induced physiological stress in freshwater teleost Oncorhynchus mykiss were investigated in this study. Forty-eight juvenile rainbow trout were divided randomly into four groups, i.e., control group, VRP group (100 μ.g/L VRP), Cd group (50 μg/L Cd~(2+)), and VRP+Cd group (100 μg/L VRP+ 50 μg/L Cd~(2+)). After 1-week exposure, oxidative stress indices (lipid peroxidation and carbonyl protein) and antioxidant parameters (superoxide dismutase, gluta-thione reductase, glutathione peroxidase, and reduced glutathione) were measured in gill and liver of all tested fish. Additionally, the behavioral changes were recorded during the experimental period. Compared with the control, cadmium-induced stress was apparent as reflected by a serious oxidative stress in gill and liver tissues, inhibited branchial antioxidant parame ters, and induced hepatic antioxidant responses, as well as abnormal behaviors observed. In the VRP+Cd group, the antioxidant defense system of fish returned to the control level, and the fish behavioral abnormal ism markedly decreased. The present results suggested that VRP could reduce the cadmium-induced physiological stress in rainbow trout and provided further evidence that Cd~(2+) uptake through Ca~(2+) transport pathways in freshwater teleost.