RESUMO
The present study was conducted to examine the biochemical and histopathological changes in liver of albino rats with oral sub-lethal (20 mg/kg) administration of chlorpyrifos as single, double and multiple doses with 48 hr intervals. Protease and glutamate dehydrogenase (GDH) enzyme activities increased in a dose and time dependent manner. Chlorpyrifos-induced histopathological changes included central venous congestion, sinusoidal haemorrhages, and focal necrotic areas in liver. Diffuse haemorrhagic areas were observed in the heart. Degenerative changes in the muscle layer, hypertrophy of goblet cells, and infiltration and hyperaemic changes in blood vessels were observed in the intestine. These results suggest that structural integrity of certain organ systems can be disrupted to a great extent from chlorpyrifos exposure.
RESUMO
This study reveals significant variations in dehydrogenase enzymes on administration of oral, sublethal (41mg/kg) doses of cypermethrin as single, double and multiple doses with 48hr intervals. Glucose-6-phosphate dehydrogenase (G-6-PDH) and lactate dehydrogenase (LDH) activities were increased, whereas succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) activities were significantly decreased in muscle and heart tissues of albino rats, in a dose and time dependent manner. G-6-PDH is a key enzyme of HMP pathway. This pathway serves to generate glycolytic intermediates for the production of energy to tolerate toxic stress. SDH is a vital enzyme of citric acid cycle, and catalyses the reversible oxidation of succinate to fumarate. LDH activity shows an increase during anaerobic conditions to meet the energy demands. MDH activity depends on fluctuations of oxidative metabolism, and also reflects the turnover of carbohydrates and energy output.