[Cellular energy metabolism in rats receiving diets contaminated with lindane].

Young male rats, Wistar CF strain, about 70 g body weight, were fed a well-balanced diet containing 0 (control), 60 or 240 ppm lindane. The day before the experiment, all the animals were fasted, and some of them placed in a restraint wheel forcing them to walk on during 18 hrs; another group was given an i.p. injection of 2.6 g/kg glucose 30 minutes before their sacrifice. The redox and energy potentials of liver and muscle tissues were estimated after the determination of the following compounds: lactate, pyruvate, beta-hydroxybutyrate, acetoacetate, ATP, ADP, AMP, inorganic phosphate, NADP and NADPH. No effect of lindane was observed on muscle metabolism and the 60 ppm dose was without significant effect on liver metabolism. At the 240 ppm dosage: a. Lindane ingestion increased the liver betaHOB/AcAc ratio and decreased the Lac/pyr ratio. The ATP/ADP ratio was not significantly lowered, although the ATP concentration was diminished and, conversely, the AMP and inorganic P ones were elevated; b. Whereas lindane lowered the glucose effect on the mitochondrial redox potential, it had no influence on the increasing of the ATP/ADP ratio by glucose, or on the antiketogenic effect of this sugar; c. In the animals fed the lindane-contaminated diet, muscular exercise increased the liver betaHOB/AcAc and NADPH/NADP ratios, while the lac/pyr and ATP/ADP ratios were unaltered. But blood pyruvate was increased. The following interpretation has been given. Lindane ingestion inhibits liver mitochondrial activity and increases ketogenesis. The glucose treatment results in a poor glucose utilization for energy needs in the contaminated animals and the forced muscular exercise shows that gluconeogenesis proceeds at a slower rate than in the controls. It is suggested that an increased demand in NADPH, as resulting from the induction of the microsomal enzymes by lindane, is one of the mechanisms by which the pesticide inhibits the activity of the tricarboxylic acid cycle.