Biochemical investigations on monocrotophos exposed fish, Channa gachua (Ham.)

The freshwater fish, Channa gachua was exposed to sub-lethal concentrations of an organophosphorus pesticide, monocrotophos. The fish was exposed to acute toxicity of monocrotophos for 16, 24 and 48 hours while for chronic toxicity it was exposed for 15, 30 and 45 days. The monocrotophos was found to be toxic to the fish, which was found to be increasing with the increase of its concentration. Alterations in various biochemical parameters of fish were observed. The exposure of 0.072 ppm concentration of monocrotophos led to the addition in cholesterol, alkaline phosphatase in plasma, triglyceride in plasma, serum bilirubin, serum creatinine, SGPT and SGOT while reduction in plasma glucose, total protein and lipid peroxidation.


Collection of blood
After each exposure period, the blood was drawn from the dorsal aorta into plastic vials containing 0.1 ml of EDTA for biochemical tests.Then, the blood was gently mixed with the oxalate mixture to avoid coagulation.The biochemical tests were performed by using the kit procured from Merck.

Statistical analysis
The obtained data were subjected to students "t" test to find out the significance of the difference between control and treated values.

RESULTS
In the present study, attempts have been made to investigate the effect of sub-lethal concentrations of monocrotophos on various biochemical parameters.The exposure of 0.072 ppm concentration of monocrotophos led to the addition in cholesterol, alkaline phosphatase in plasma, triglyceride in plasma, serum bilirubin, serum creatinine, SGPT and SGOT while reduction in plasma glucose, total protein and lipid peroxidation in both acute and chronic studies.

Acute studies
In 16 hr exposed fishes, the recorded values of plasma glucose, cholesterol, alkaline phosphatase in plasma, triglyceride in plasma, total protein, serum bilirubin, serum creatinine, SGPT, SGOT and lipid peroxidation were 64.738 + 0.570 mg/dl, 157.Organophosphorus pesticides are generally much more acute toxic to vertebrates and other aquatic animals.Pesticides containing chlorinated hydrocarbons persist in the environment and are known to have drifted over thousands of kilometers in the water from Antarctic snow.Traces of chlorinated hydrocarbon pesticides in water may be accumulated in fishes up to the levels of more than 10,000 times, the concentration present in the surrounding water.Several pesticides including some, those were washed extensively in agriculture in the past and some, those are still used for the purpose of disease control, have been shown to produce tumors in animals.
Gopal et al., (1980) studied endosulphan induced hyperglycemia in the catfish, Clarias batrachus.Mukhopadhyay and Dahadrai (1980) observed a marked decline in liver glycogen and protein contents in the catfish with sublethal concentration of malathion.Sastry and Sharma (1981), and Singh and Shrivastava (1981) studied variations in various carbohydrate metabolites in Ophiocephalus punctatus and Heteropneustes fossilis treated to toxicants and a mixture of aldrin and formathion, respectively.Carbofuran induced alterations in the activities of alkaline and acid phosphatases.GOT and GPT have been studied in the air-breathing catfish, Clarias batrachus (Mukhopadhyay et al.,1982).Murthy and Devi (1982) reported decreased level of protein, glycogen and lipid concentration in liver, and increased level in brain of Channa punctatus treated with endosulphan.Hyperglycemia, hepatic and muscle glycogenolysis, hyperlactemia and enhanced pyruvate concentrations have been reported in Channa punctatus exposed to sevin (Sastry and Siddiqui, 1982).Mishra and Shrivastava (1983) have noticed hyperglycemia and muscle glycogenolysis in H. fossilis treated to malathion.Sastry and Siddiqui (1984)

Table - 2: Sub-lethal effect of Monocrotophos on certain biochemical parameters of Channa gachua (Ham.) Chronic studies (0.072 ppm/L) S. Parameters Treated Tested After 16 hrs. After 24 hrs. After 48 hrs.
found alterations in levels of plasma protein, glucose, glycogen and lactate concentrations in Channa punctatus exposed to sublethal concentration of quinolphos.Gluth and Hanke (1985) observed a consistent decrease in protein and cholesterol contents in Cyprinus carpio induced by sublethal concentrations of several pollutants.Ram and Sathyanesan (1987) studied the effect of cythion on the protein level in brain, liver and ovary of Channa punctatus.Joshi and Desai (1988) noticed biochemical changes in the liver of Tilapia mossambica during continuous exposure to monocrotophos.Alterations in blood glucose values have been reported in H. fossilis exposed to sublethal concentration of chlordane for 15,30, 50 and 70 days (Shrivastava and Shrivastava, 1988).Sub lethal concentrations of nuvan exhibited marked changes in the values of protein, carbohydrate and lipid reserves in blood, brain, liver, kidney, testis and ovaries of Channa punctatus (Ghosh and Chatterjee, 1989).Rani et al., (1989) noticed a significant decrease in the activities of lactate dehydrogenase and increase in glucose and lactate levels in Clarias batrachus exposed to trichlorfom and methyl parathion.Sastry and Dasgupta (1991) and Yasmeen et al., (1991) noticed significant alterations in blood glucose, lactic acid and protein in Clarias batrachus, Anguilla anguilla and Channa punctatus acutely or chronically exposed to aldrin, lindane and nuvacron.Baigh et al., (1991) noticed heptachlor induced changes in protein, glycogen and lactic acid contents in functionally different muscles of Channa punctatus.Singh and Shrivastava (1993) have noticed hyperglycemia in H. fossilis treated with sub-lethal concentrations of organochlorine and organophosphate insecticides.