Effects of Atrazine on Blood Indices and Histopathology of Grass Carp (Ctenopharhyngoden idella)

Atrazine is currently the most widely used herbicide in the south of Iran. The chronic toxicity effects of atrazine(herbicide) on blood indices and histopathology of the gill, liver and kidney in grass carp(Ctenopharhyngoden idella) were studied by exposing them to sublethal concentrations of atrazine to 0, 10, 100, 1 000, 10 000 g atrazine per liter of water for a period of 30 days. Up to 100 g·L-1, atrazine did not show significant toxicity.In contrast, atrazine in the concentration of 1 000 and 10 000 g·L-1significantly increased toxicity effects on studied parameters. The highest mortality rate(100%) was observed at 10 000 g·L-1on the day 10 and at 1 000 g·L-1on the day 20. Cytological analysis showed that haematocrit(Hct) increased significantly with the increase of atrazine concentration and days. White blood cells(WBC), red blood cells(RBC) and hemoglobin(Hb) were changed significantly(p < 0.05) in different treatments. Biochemical analysis indicated that plasma total protein, albumin, glucose, cholesterol and triglycerides levels decreased significantly(p < 0.05) with the increase of atrazine concentrations and exposure days. Histopathological studies showed hyperplasia, hyperemia, necrosis, mucosa secretion, shortness of filaments, lamellar fusion in gills; necrosis, anemia, bile stagnation in liver; and cell atrophy, hyperemia, hemorrhage and necrosis in kidney which were more severed at 1 000 and 10 000 g·L-1. Therefore, mentioned effects on studied histopathological and some blood parameters were both dose-and time-dependent. In sum, the atrazine exposure of grass carp at concentrations 1 000 and 10 000 g·L-1induced significant changes in blood indices and structural disruptions in gill, liver and kidney organs on days 20 and 10, respectively. The obtained results indicated the atrazine is toxic and could damage vital organs and blood of grass carp. Therefore, the use of atrazine should be imperative and carefully monitored.

Atrazine is currently the most widely used herbicide in the south of Iran. The chronic toxicity effects of atrazine （herbicide） on blood indices and histopathology of the gill, liver and kidney in grass carp （Ctenopha- rhyngoden idella） were studied by exposing them to sublethal concentrations of atrazine to 0, 10, 100, 1 000, 10 000 g atrazine per liter of water for a period of 30 days. Up to 100 g·L^-1, atrazine did not show significant toxicity. In contrast, atrazine in the concentration ofl 000 and 10 000 g·L^-1 significantly increased toxicity effects on stud- ied parameters. The highest mortality rate （100%）was observed at 10 000 g·L^-1 on the day 10and at 1 000 g·L^-1 on the day 20. Cytological analysis showed that haematocrit （Hct） increased significantly with the increase of at- razine concentration and days. White blood cells （WBC）, red blood cells （RBC） and hemoglobin （Hb） were changed significantly （p 〈0.05） in different treatments. Biochemical analysis indicated that plasma total protein, albumin, glucose, cholesterol and triglycerides levels decreased significantly （p 〈 0.05） with the increase of at- razine concentrations and exposure days. Histopathological studies showed hyperplasia, hyperemia, necrosis, mucosa secretion, shortness of filaments, lamellar fusion in gills; necrosis, anemia, bile stagnation in liver; and cell atrophy, hyperemia, hemorrhage and necrosis in kidney which were more severed at 1 000 and 10 000 g·L^-1. Therefore, mentioned effects on studied histopathological and some blood parameters were both dose - and time -dependent. In sum, the atrazine exposure of grass carp at concentrations 1 000 and 10 000 g·L^-1 induced signifi- cant changes in blood indices and structural disruptions in gill, liver and kidney organs on days 20 and 10, re- spectively. The obtained results indicated the atrazine is toxic and could damage vital organs and blood of grass carp. Therefore, the use of atrazine should be in-~erative and carefully monitored.