The osmoregulation system of freshwater fish is sensitive to salinity increase in water. There is no satisfactory data to our knowledge on the accumulation of metal-oxide nanoparticles (NPs) in tissues of O. niloticus and their effects on ATPases (Na,K-ATPase, Mg-ATPase, Ca-ATPase) in differing salinities. Thus, this study investigated the effects of salinity (0 and 10 ppt) and Al₂O₃ and TiO₂ NPs (1 and 10 mg NPs/L) on the response of ATPases in acute (2 days) and chronic (20 days) durations. Data showed that nanoparticles accumulated in the tissues of fish, gill tissues having the highest levels of Al and Ti in both acute and chronic durations. Interestingly, the higher salinity significantly increased (P < 0.05) NP accumulations in the tissues in acute exposures, whereas it significantly decreased (P < 0.05) in chronic exposures. Salinity increase caused significant decreases (P < 0.05) in ATPase activities (up to 54 %) in control fish from both exposure protocols. Likewise, NP alone exposures (up to 80 %) and salt+NP (up to 83 %) exposures generally caused significant (P < 0.05) decreases in ATPase activities compared to their controls. Similarly, salt+NP exposures also decreased ATPase activities compared to NP exposures alone. The present data demonstrated that salinity and/or NP exposures decreased ATPase activities in the gill of freshwater fish, emphasizing the possible hazardous consequences of salt inputs and NP discharges into freshwater systems.

淡水鱼的渗透压调节系统对水中盐度的增加很敏感。关于金属氧化物纳米粒子（NPs）在尼罗罗非鱼组织中的积累及其在不同盐度下对 ATP 酶（Na、K-ATP 酶、Mg-ATP 酶、Ca-ATP 酶）的影响，目前还没有令人满意的数据。因此，本研究调查了盐度（0 和 10 ppt）以及 Al ₂ O ₃和 TiO _{2的影响。}NPs（1 和 10 mg NPs/L）在急性（2 天）和慢性（20 天）期间对 ATP 酶的反应。数据显示，纳米粒子在鱼的组织中积累，在急性和慢性持续时间中，Al 和 Ti 含量最高的鳃组织。有趣的是，较高的盐度显着增加（P < 0.05）急性暴露在组织中的NP 积累，而在慢性暴露中显着降低（P < 0.05）。在两种暴露方案中，盐度增加导致对照鱼的 ATP 酶活性显着降低 (P < 0.05)（高达 54%）。同样，与对照组相比，NP 单独暴露（高达 80%）和盐+NP（高达 83%）暴露通常会导致 ATP 酶活性显着降低（P < 0.05）。相似地，与单独的 NP 暴露相比，盐 + NP 暴露也降低了 ATPase 活性。目前的数据表明，盐度和/或 NP 暴露降低了淡水鱼鳃中的 ATP 酶活性，强调了盐输入和 NP 排放到淡水系统中可能产生的危险后果。