Histopathology and Oxidative Stress in the Liver of Chalcalburnus Tarichi Living in Lake Van, Turkey

Abstract

To assess the environmental quality in the Lake Van, Chalcalburnus tarichi, the only vertebrate and an endemic carp species of this lake basin, samples were collected from the lake, and their livers were examined histologically for this purpose. Histological alterations were recorded and evaluated semi-quantitatively based on the liver lesion categories and their severities. According to the results, five of a total of forty samples displayed normal (healthy) liver architecture, but the others displayed various histopathological alterations, including hepatocyte vacuolization, fatty degeneration, increase in melanomacrophage centers, necrosis, infiltration, congestion, fibrosis, single cell necrosis, bile duct alterations, glycogen depletion and nuclear pleomorphism. Liver index values were calculated and found to be changed between 2 and 50 (≤4 for fish with normal livers (FwNL) and ≥8-50 for fish with histopathological livers (FwHL). We also investigated oxidative stress biomarkers, lipid peroxidation (LPO) and antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) in FwHL as compared with FwNL. LPO and CAT were found to be significantly higher in FwHL, indicating increased oxidative stress. The results revealed that the observed histological and biochemical alterations in the livers of C. tarichi reflect the effects of environmental stressors present in the lake water causing pollution.