Effect of dieldrin on certain enzyme systems of rat liver.

The effect of a single oral dose of dieldrin (30 mg/kg body weight) on certain hepatic enzyme systems involved in carbohydrate metabolism and liver function has been investigated. Dieldrin inhibits the initial phosphorylation process of glucose by lowering the activities of glucokinase and hexokinase. The resultant inhibition of glycolysis together with the increase in the activities of hepatic lactate dehydrogenase and malate dehydrogenase argue in favour of a stimulation of gluconeogenesis by the insecticide. The aerobic metabolism of glucose is also affected, as indicated by the lowered activities of isocitrate dehydrogenase and succinate dehydrogenase. The insecticide mediated augmentation of hexose monophosphate shunt pathway suggests direct oxidation of glucose. The changes in the activities of hepatic alkaline phosphatase and adenosine triphosphatase are indicative of an impairment of liver function and altered mitochondrial morphology.