**22. Conclusion**

In conclusion, the present literature review shows that exposure to insecticides, firstly, caused an induction of antioxidant enzyme activities indicating the activation of the insecticides de‐ toxification pathways and the antioxidant defenses. However, acute to chronic insecticides treatment disrupted the behavioral response, alterations hematological, biochemical and im‐

**Figure 5.** Intestine of rainbow trout from the control group (A): Mucosal epithelium (ME), Lamia's propria (LP), Submucosa layer (SML), Muscularis layer (ML), Serosa layer (SL). Intestine of rainbow trout exposed to 0.01 mg/L diazinon (B): Desquamating of the mucosal epithelium; Intestine of rainbow trout exposed to 0.02 mg/L diazinon (C): Mucosal epithelial hyperplasia, severe necrosis in the mucous layer, loss of the intestine microvilli, disorganization in arrange‐ ment of circular and longitudinal muscles in muscularis layer, loss of muscle elasticity and flexibility of the intestine. Figures are representatives of three replicate experiments (magnification of the sections 400X).

The ovaries of *C. carpio* have shown significant changes on exposure to sub-lethal concentra‐ tion of diazinon. The oocyte with de-shaped yolk vesicles, vacuolated follicular epithelium and degenerative cytoplasm were reported in fish exposed to diazinon by Banaee et al., 2008.

**Figure 4.** Spleen of rainbow trout from the control group (A): With pulp (WP), Red Pulp (RP), Spleen of rainbow trout exposed to 0.01 mg/L diazinon (B): Melanomacrophage centers (MC), Ellipsoid cells (EC), Penicillus (P), Expansion of splenic red pulp and melano-macrophage centers, disorientation in ellipsoid cells; Spleen of rainbow trout exposed to 0.02 mg/L diazinon (C): Disorder in ellipsoid cells, the increase of number and size of melano-macrophage centers, and cloudy swelling in spleen tissue (CS). Figures are representatives of three replicate experiments (magnification of

In conclusion, the present literature review shows that exposure to insecticides, firstly, caused an induction of antioxidant enzyme activities indicating the activation of the insecticides de‐ toxification pathways and the antioxidant defenses. However, acute to chronic insecticides treatment disrupted the behavioral response, alterations hematological, biochemical and im‐

**22. Conclusion**

the sections 400X).

126 Insecticides - Development of Safer and More Effective Technologies

munological parameters. In addition, the histopathological analysis performed in gills, liver, spleen, kidney, gonads and intestine of fish exposed to different concentration of insecticides reported significant damage in all tissues indicating that it was a useful methodology for moni‐ toring the effects of insecticides on wild and cultured fish. These changes may be potentially disruptive for the survivability of fish in aquaculture farm and natural resources. This fact should be taken into consideration when this insecticide is used for pest control in agriculture fields surrounding surface water and ground water resources.
