Effects of Acute Malathion Exposure on Liver Mitochondrial Respiratory Chain Enzymes in Rats

Abstract

Malathion is an organophosphorus insecticide widely used to control pests. Previous toxicological studies attributed to the ability of Malathion to effect on cellular metabolism. The main objective of present study was to find out what actually happens on the activities of key enzymes of the mitochondrial respiratory chain after acute exposure to Malathion. To design an acute toxicity study, all male Wistar rats were given Malathion at a single oral dose of 400 mg/kg. Activities of plasma acetylcholinesterase (AchE) and liver mitochondrial respiratory chain enzymes were measured after 24 h. Inhibition of AchE was accompanied by depressed nicotinamide adenine dinucleotide-ubiquinone oxidoreductase, and cytochrome C oxidase enzymes activity in the mitochondrial respiratory chain. On the other hand, Malathion did not significantly change succinate-ubiquinone oxidoreductase, and adenosine triphosphate synthase enzymes activity. It can be concluded that Malathion by extra energy demand in cholinergic storm phase reduced glycogen content of liver to supply glucose. On the other hand, inhibition of the mitochondrial respiratory chain key enzymes activity shift cellular glucose metabolism from mitochondrial respiration to anaerobic glycolysis pathway to provide demanded energy.