Evaluation of histological architecture, cellular apoptosis, dinitrophenyl protein and superoxide dismutase expressions in the gills of goldfish exposed to environmentally relevant pesticide mixtures: Potential mechanisms to disrupt osmoregulation

Pesticides are regularly used in agricultural production to increase crop yields and eliminate targeted pests. Unfortunately, these pesticides enter aquatic environments through surface runoff. In this study, we examined the effects of short-term exposure (one-week) to environmentally relevant pesticide mixtures (alconifen, atrazine, azinphos-methyl, isoproturon, linuron, metolachlor, pendimethalin, and tebucanazole) on gill architecture, oxidative stress biomarker, and cellular apoptosis in goldfish (Carassius auratus). Histological analysis revealed morphological alterations in the gills of fish exposed to both low- and high-dose pesticide mixtures. Immunohistological and real-time PCR results showed a significant upregulation of dinitrophenyl protein and superoxide dismutase mRNA expressions in the gills of fish exposed to pesticide mixtures. In situ TUNEL assay demonstrated a substantial increase in apoptotic nuclei in the gills of fish exposed to pesticide mixtures. Together, these results suggest that short-term exposure to environmentally relevant pesticide mixtures disrupts the morphology and cellular functions in the gills of teleost fishes.