ABSTRACT
In the present study, an organophosphorus compound Coroban (active ingredient chlorpyrifos E.C. 20%) was used. In short-term exposure the fish were subjected to 0.8 of 96h LC50 value of chlorpyrifos (1.76 mg L-1) for 96h. In long-term exposure the experiment was performed for 28 days by using 0.2 of 96h LC50 value of chlorpyrifos (0.44 mg L-1). Fish were killed on each time intervals from control and experimental (chlorpyrifos) groups after 24, 48, 72, and 96h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood samples were collected and sera were analyzed for calcium. Pituitary glands were fixed for histological studies and stained with Herlant tetrachrome and Heidenhain's azan techniques. Short-term exposure of chlorpyrifos caused decrease in the serum calcium levels. No change was noticed in the prolactin cells of chlorpyrifos treated fish. Long-term treatment with chlorpyrifos provoked hypocalcemia. The prolactin cells of treated fish exhibited slight degranulation after 21 days whereas the nuclear volume remained unchanged. After 28 days, the prolactin cells exhibited further degranulation and the nuclear volume recorded an increase. Cytolysis and vacuolization were also visible.
No estudo presente, o composto organofosforo Coroban (ingrediente ativo clorpirifo E.C. 20%) foi usado. Na exposição a curto prazo os peixes foram submetido a 0,8 de valor LC50 de 96h de clorpirifo (1,76 mg L-1) durante 96h. Na exposição a longo prazo o experimento foi executado durante 28 dias usando 0,2 de valor LC50 de 96h de clorpirifos (0,44 mg L-1). Os peixes foram mortos a cada intervalo dos grupos controle e experimental (clorpirifos) após 24, 48, 72, e 96h em exposição a curto prazo e após 7, 14, 21, e 28 dias no experimento a longo prazo. As amostras de sangue foram colhidas e o soro foi analisado para cálcio. As glândulas pituitárias foram fixadas para estudos histológicos e colorido por tetracromo de Herlant e por técnicas de azan do Heidenhain. A exposição a curto prazo do clorpirifo diminuiu os níveis de cálcio no soro. Nenhuma mudança foi observada nas células de prolactina nos peixes tratados com clorpirifo. O tratamento a longo prazo com clorpirifo causou hipocalcemia. As células de prolactina dos peixes tratados mostraram uma leve degranulação após 21 dias ao passo que o volume nuclear permaneceu inalterado. Depois de 28 dias, as células de prolactina mostraram mais degranulação e o volume nuclear registrou um aumento. Citólise e vacuolização também eram visíveis.
Subject(s)
Animals , Organophosphates , Prolactin , Catfishes , Chlorpyrifos , Fresh WaterABSTRACT
In the present study, an organophosphorus compound Coroban (active ingredient chlorpyrifos E.C. 20%) was used. In short-term exposure the fish were subjected to 0.8 of 96h LC50 value of chlorpyrifos (1.76 mg L-1) for 96h. In long-term exposure the experiment was performed for 28 days by using 0.2 of 96h LC50 value of chlorpyrifos (0.44 mg L-1). Fish were killed on each time intervals from control and experimental (chlorpyrifos) groups after 24, 48, 72, and 96h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood samples were collected and sera were analyzed for calcium. Pituitary glands were fixed for histological studies and stained with Herlant tetrachrome and Heidenhains azan techniques. Short-term exposure of chlorpyrifos caused decrease in the serum calcium levels. No change was noticed in the prolactin cells of chlorpyrifos treated fish. Long-term treatment with chlorpyrifos provoked hypocalcemia. The prolactin cells of treated fish exhibited slight degranulation after 21 days whereas the nuclear volume remained unchanged. After 28 days, the prolactin cells exhibited further degranulation and the nuclear volume recorded an increase. Cytolysis and vacuolization were also visible.