Effects of manganese on fat snook Centropomus parallelus (Carangaria: Centropomidae) exposed to different temperatures

ABSTRACT

This study evaluates the effects of exposure to manganese (Mn²⁺) for 96 hours at two different temperatures (24 and 27°C) on juveniles of Centropomus parallelus through the activities of glutathione S-transferase (GST) and catalase (CAT), micronuclei test (MN) and comet assay. The GST activity did not show any significant difference between the groups exposed to Mn²⁺ and the respective control groups; in contrast, a major increase in the CAT activity was observed at 27°C in the group exposed to Mn²⁺ compared to the control group. The genotoxic analyses showed that in all animals exposed to Mn²⁺, the number of red cells with micronuclei increased significantly compared to the respective control groups. There was also a significant increase in the incidence of DNA damage in the groups exposed to Mn²⁺. At a temperature of 24ºC, animals exposed to Mn²⁺ had more DNA damage than those at 27°C. It is likely that the increase in temperature can also induce oxidative stress. Thus, we conclude that manganese is toxic to the fat snook juveniles, causing genotoxic damage, and when associated with an increase in temperature, manganese can also provoke an increase in oxidative stress.

Keywords:
Biomarkers; DNA damage; Enzymes; Genotoxicity; Metal; Micronuclei