Study effect of sub-lethal concentrations of diazinon on some serum enzymes of male brood stocks

    The effects sub-lethal concentrations of diazinon on some enzymes parameters of kutum (Rutilus frisii kutum, Kamensky, 1901) weighing 613.33 g ± 157.06 g were studied under static water quality conditions at 15 °C ± 2 ºC in winter and spring 2009. The first test was conducted to determine the effects of acute toxicity (LC5096 h) of the diazinon (emulsion 60%) on kutum male brood stocks. For this purpose, 4 treatments were used to test toxicity; each treatment was repeated in 3 tanks with 9 fish per treatment and with 180 litres water capacity. After obtaining the final results, the data were analysed statistically with Probit version 1.5, and we determined the LC10, LC50 and LC90 values at 24 hours, 48 hours, 72 hours and 96 hours; the maximum allowable concentration value (LC5096 h divided by 10); and the degree of toxicity. The second stage of testing consists of four treatments: LC0= 0 as experimental treatment, treatment A with a concentration of LC1= 0.107 mg/L, treatment B with concentration of LC5= 0.157 mg/L, treatment C with concentration of MAC value= 0.04 mg/L. Male brood stocks of kutum were treated with these concentrations for 45 days. Experiments were carried out under static conditions based on the standard TRC, 1984 method over 45 days. Our results showed that long-term exposure to diazinon causes a decrease in the lactate dehydrogenase (LDH) and cholinesterase (CHeS). In addition, diazinon also causes an increase in aspartate aminotransferase (AST) and alkaline phosphatase (ALP) (P<0.05). The results indicated that long-term exposure to low concentrations of diazinon causes changes in some serum enzymes of R. frisii male brood stocks.