Assessment of histopathological and micronucleus test with genotoxic effects of hexavalent chromium on mirror carps (Cyprinus carpio)

In the present study, genotoxic effects was evaluated using the micronucleus frequency and histopathological changes analyzed using gill, muscle and hepatopancreas tissues under laboratory conditions in carp (Cyprinus carpio).Fish were exposed to sublethal concentrations of chromium (VI) during 14 days. Blood and other tissue samples were taken after 7 and 14 days of exposure.Following routine histological procedures of prepared tissue slides were stained with Hematoxylin-Eosin (H.E.) and mason trichrome then evaluated under a light microscope. Frequencies of erythrocytic nuclear abnormalities such as, micronuclei (MN) were investigated in peripheral blood of fish.A dose and time dependent histopathological changes: Increase in collagen between the muscle fibers, infiltration in mononuclear cells at connective tissue, atrophy of the muscle fibers, vacuolation and destruction; basal membrane thickening of the gill bar, epithelial hyperplasia, oedema, filament epithelium, hyperplasia of secondary lamellar cells, congestion of capillaries and peri capillary oedema, aneurism; degeneration of liver parenchymal cells, excessive accumulation of fat, vacuolation, pycknotic nucleus, necrotic and degenerative spaces, increase in kupffer cells, sinusoids congestion and dilatation observed. Micronucleus frequency increased depending on exposure time and concentration.These results indicated that chromium (VI) had histopathological and genotoxic effects on carp (Cyprinus carpio).