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.