Abstract
The effects of Copper Sulfate (CuSO4) on repaired the histopthological changes on liver of Cyprinus carpio exposed to
nano zinc oxide (N-ZnO) was determined in this study.Fish weight 150±10 g divided in to four groups.Fish in first group kept
in dechlorinated water while the fish in second group exposed to copper sulfate CuSO4 for 1 hour and in third group the fish
was exposed to sub lethal concentration of N-ZnO (30ppm) for 7 days while the fish in fourth group exposed to sub lethal
concentration of N-ZnO (30ppm) with CuSO4 (0.3mgL) for 1hour and then exposed continuously to N-ZnO for 7days. The
microscopic examination for the liver done through 24 hour and 7 days from the experiment, which revealed vacuolar
degeneration in hepatic cells in fish exposed to N-ZnO for 24 hour also there were dilatation of sinusoid and infiltration of
inflammatory cells in liver tissue of fish exposed to to N-ZnO with CuSO4 for 1 hour, there were slight hemorrhage in hepatic
tissue and enlargement of hepatic cell in both groups exposed to N-ZnO and CuSO4 for 1 and 24 hour, while the
microscopically examination of liver in fish exposed to N-ZnO for 7 days revealed sever pathological lesions characterized by
hyperatrophy and necrosis in pancreatic tissue. This study concluded that N-ZnO can cause oxidative stress and usage of
CuSO4 at 0.3 mg/L can decrease the toxic effects of N-ZnO liver tissue