The effect of pyrethroid pesticide deltamethrin on the liver histology and fatty acid composition of freshwater fish Oreochromis niloticus and the protecti ve effect of vitamin E

The aim of this study is to determine the alterations occuring in gill and liver histology and fatty acid composition in phospholipid fraction of gill, liver and muscle of Oreochromis niloticus exposed to deltamethrin and to examine the possible protective effects of usage of vitamin E on this subject.For experimental study 4 groups; Group-I (control group) containing the fish fed with normal diet without pesticide, Group-II containing the fish fed with vitamin E supplemented diet (100 mg 100 mg alpha-tocoperol/kg food), Group-III containing fish exposed to 10% concentration of deltamethrin and fed with normal diet and Group-IV containing fish exposed to 10% consentration of deltamethrin and fed with vitamin E supplemented diet, were chosen.In order to determine histopathological alterations, the gill and livers of fish which were taken from each groups at 10th, 20th and 30th days were examined. In the examinations it was observed that the most effected tissue was gill and then liver. In gill tissues of fish taken from Group-III and Group-IV which were exposed to deltamethrin, lessions such as epithelial hypertrophy, lamellar epithelial lifting, hypertrophy of mucus cells, mucus accumulation in secondary lamellae, epithelial hyperplasia and fusion of secondary lamellae were observed. From the group streated with pesticides, when Group-III and Group-IV were compared, all lessions observed in Group-III were also noticed in Group-IV,except pillar cell break age. In addition, aneurysm which was not noticed in Group-III was observed in Group-IV. The lessions which were determined in Group-III such as epithelial hyperplasia, fusion of secondary lamellae showed a slight recovery in Group-IV.In the liver tissues of pesticide treated Oreochromis niloticus alterations such as hypertrophy, vacuolar degeneration, pyknotic nuclei, focal necrosis and double-nuclei cells were detected. From the pesticide treated groups; when Group-III and Group-IV were compared, the great majority of lessions observed in Group-III showed a recovery in Group-IV.In order to determine the alterations occurring in fatty acid composition in phospholipid layer of gill, liver and muscle tissues of the fish exposed to deltamethrin, samples were taken at 10th, 20th and 30th days from each groups. In the comparisons of Group-II, Group-III and Group-IV with the control group Group-I, irregular incerases and decreases were determined in fatty acid percentages. Differences in various days in various rates were observed in the total saturated ?-9, ?-6 and ?-3 fatty acid percentages.