Histological study and evaluation of Hsp70 gene expression in gill and liver tissues of goldfish (Carassius auratus) exposed to Zinc oxide nanoparticles

In parallel with the increased use of nano-sized metallic materials, the possibility of their release into the environment has increased in recent decades. However, there is not sufficient information on the toxic potential of these materials on different aspects of the life history of aquatic organisms. In this study, we investigated the impact of zinc oxide nanoparticles (ZnO-NPs) on goldfish by studying histopathological alteration and Hsp70 gene expression in gill and liver tissues. The results showed that after exposure to different concentrations of ZnO-NPs, severe lesions were observed in the gill and liver tissues of goldfish. Expression of Hsp70 significantly increased in comparison with the control group and this increase was observed especially in the initial sampling times. Also expression pattern of Hsp70 is relatively similar in gill and liver tissues of goldfish. Based on the results of the present study, ZnO-NPs, as widely used nanoparticles can endanger the health of goldfish and further studies are needed to evaluate its potential toxic effects.