In vitro study of histopathological effects of Pyrene oil composition on some vital organs of carp(Cyprinus carpio)

The effects of pyrene on gill, liver and kidney of common carp (Cyprinus carpio) were examined by exposing 30 fish (140 ±10 g to pyrene at sublethal concentrations of 10, 50 and 100 µg/l for 35 days. Samples were taken from the organs and fixed in bouin fixative; then, dehydrated, cleared, parafinated and cut by microtome according to the standard method. Afterwards, all sections were studied by light microscope. In gill tissue, lamella hyperemia, hyperplasia, S shaped, and clubbing were observed, while lamella fusion and necrosis were observed in higher concentration of pyrene. Hepatocytes vacculation, congestion of sinusoids, macrophages loaded with hemosiderin were seen in the liver, while in higher concentrations of pyrene, picnotic and kariolized nuclei, and tissue necrosis were seen. Tubule casts, hyperemia, degenerating tubules were seen in kidney exposed to lower concentrations of pyrene, while hemosiderin-laden macrophages, degenerating tubules with greater intensity as well as necrosis was observed in higher concentrations. The results indicated that pyrene may have negative effects on homeostasis, fish health and vital organs in short time exposure due to histological changes, while it could have greater impacts in long term exposure and higher concentrations.