Effect of Chronic Hydrogen Peroxide Exposure on Ion Transport in Gills of Common Carp (Cyprinus carpio)

High environmental hydrogen peroxide (H2O2) has been demonstrated to be toxic for fish. However, the response mechanism of fish chronic H2O2 exposure is not yet well understood. Therefore, this study aimed investigate alteration in ion transport gills and analyzed potential after exposure. The common carps were exposed 0, 0.25, 0.50, 1.00 mM 14 days. histopathological evaluation results indicated that caused incomplete gill filament structure. In plasma, suppressed potassium (K+) concentration but increased sodium (Na+) concentration. gills, calcium (Ca2+) level was raised, K+ chlorine (Cl−) levels decreased After days exposure, prompted activities Ca2+/Mg2+-ATPase H+/K+-ATPase Na+/K+-ATPase activity gills. Gene transcription analysis showed ion-regulation-related genes including nkaa rhbg downregulated addition, upregulated mRNA cam camk II, indicating Ca2+ singling pathway activated. conclusion, our data altered structure disturbed transport, which further negatively affected equilibrium ions osmotic pressure.