Effects of in vivo exposures to nanoparticles (Al<sub>2</sub>O<sub>3</sub>, CuO, TiO<sub>2</sub>) on the activities of ATPases in the gill and muscle of freshwater mussel (Unio tigridis)

Abstract

Mussels are effective bioindicator organisms for aquatic environments. Therefore, they were often used to determine the effects of various xenobiotics in the aquatic systems. There is no study to our knowledge on the in vivo effects of nanoparticles (NPs) on the activities of ATPases in freshwater mussels (Unio tigridis). This work demonstrates the effects of Al$_{2}$O$_{3}$, CuO, and TiO$_{2}$ NPs on Na- ATPase, Ca-ATPase, and Mg-ATPase activities in the gill and muscle of mussels following 14-day exposures to different concentrations of NPs (0, 1, 3, 9 mg/L). Mussels were fed with laboratory cultured algae (Chlorella vulgaris) during the exposures. There was no ouabainsensitive ATPase activity in the tissues of U. tigridis. The activities of Na-ATPase and Ca-ATPase in the gill decreased significantly (p < 0.05), while Mg-ATPase activity increased. However, the activities of all ATPases decreased significantly after NP exposures in the muscle. There were more significant alterations in the gill compared to the alterations in the muscle. The order of NP effects was determined as TiO$_{2}$ > CuO > Al$_{2}$O$_{3}$. There was no significant alteration in algae consumption between control and NP-exposed mussels. The present study reporting the first data on the effects of NPs in U. tigridis demonstrated the sensitivity of mussel physiology towards NP exposures, suggesting further studies to understand better the physiological response of mussels.