In vivo effect of monocrotophos on the carbohydrate metabolism of the freshwater snake head fish, Channa punctatus

Abstract

Alterations in the levels of some biochemical and enzymological parameters in blood, liver, and muscle of Channa punctatus exposed to LC 50 for 96 hr (10 ppm) and a sublethal concentration of the organophosphate pesticide monocrotophos 1 ppm for 15, 30, 60, and 120 days were studied. Fish exposed for 96 hr and 15 days were hypoglycemic and hypolactemic. A decrease was noted in the pyruvic acid level of blood and the activity of hexokinase in liver. In muscle, a decrease in the glycogen content and an increase in the lactic acid level indicate hyperactivity. After 30 days of exposure, hyperglycemia, hyperlactemia, a decrease in liver glycogen, and increase in the muscle glycogen and in the activity of hexokinase, and a decrease in the activities of malate dehydrogenase (MDH) and succinate dehydrogenase (SDH) indicate that anaerobic metabolism prevailed over aerobic metabolism. After 60 and 120 days of exposure, both aerobic and anaerobic pathways were impaired as evidenced by the hypoglycemia, the hypolactemia, the decrease in the pyruvic acid level of blood, the increase in the glycogen content of both liver and muscle, and the decrease in the activities of glucose-6-phosphatase, hexokinase, SDH, and MDH. The activities of glutamate-oxalacetate transaminase and glutamate-pyruvate transaminase increased in the liver, muscle, and blood in acute exposure and in all the stages of chronic exposure.