Insecticides that disrupt the healthy functioning of the ecosystem have toxic potential on non-target organisms. Fish, an important component of the aquatic ecosystem, are exposed to these pesticides in different ways. The stress response is regarded as an adaptive mechanism that allows the fish to cope with the perceived stressor to maintain its normal or homeostatic state. This mechanism is determined by antioxidant parameters and oxidative stress indicators measured in gill and liver tissue of rainbow trout. Accordingly, the effects of fipronil (FP) insecticide on the physiology of rainbow trout (Oncorhynchus mykiss) were determined with using the different biomarkers (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), malondialdehyde (MDA), paraoxonase (PON), arylesterase (ARE), myeloperoxidase (MPO), 8-hydroxy-2-deoxyguanosine (8-OHdG)), and caspase 3 activity) in this study. Different doses of FP inhibited antioxidant enzyme activities in rainbow trout liver and gill tissues while inducing oxidative stress parameter (MDA, MPO, and 8-OHdG) levels. Also, caspase-3 activity was increased in liver and gill tissue, but this increase was statistically significant only in gill tissue (p < 0.05). When the results of the study were taken into consideration, it was concluded that different doses of FP insecticide caused physiological changes in rainbow trout and the studied parameters were usable biomarkers in explaining the adaptive response of stress factor.

破坏生态系统健康功能的杀虫剂对非目标生物具有潜在的毒性。鱼是水生生态系统的重要组成部分，以不同的方式暴露于这些农药。应激反应被认为是一种适应性机制，可以使鱼类应对感知到的应激源，以维持其正常或体内稳态。该机制由虹鳟tr和肝组织中测得的抗氧化剂参数和氧化应激指标决定。因此，氟虫腈（FP）杀虫剂对虹鳟鱼（Oncorhynchus mykiss）是使用不同的生物标记物（超氧化物歧化酶（SOD），过氧化氢酶（CAT），谷胱甘肽过氧化物酶（GPX），丙二醛（MDA），对氧磷酶（PON），芳基酯酶（ARE），髓过氧化物酶（MPO），8-羟基- 2-脱氧鸟苷（8-OHdG）和caspase 3活性）。不同剂量的FP会抑制虹鳟鱼肝脏和g组织中的抗氧化酶活性，同时诱导氧化应激参数（MDA，MPO和8-OHdG）水平。同样，caspase-3活性在肝脏和腮组织中增加，但这种增加仅在腮组织中具有统计学意义（p <0.05）。考虑到研究结果，可以得出结论，不同剂量的FP杀虫剂会引起虹鳟鱼生理变化，所研究的参数可作为解释应激因素适应性反应的有用生物标记。