Exposure to polychlorinated naphthalenes affects GABA-metabolizing enzymes in rat brain

Abstract

There is substantial evidence that polychlorinated naphthalenes (PCNs) are widespread global environmental pollutants, which accumulate in biota. The aim of our study was to characterize the effect of prolonged PCNs exposure on γ-aminobutyric acid (GABA) metabolism in rat brain regions with a high amount of GABAergic neurons (cerebellum, brain stem and basal ganglia). PCNs mixture was administered intragastrically for 7, 14 and 21 days in a dose 10 mg/kg of body weight daily, and next the activity of glutamate decarboxylase (GAD), GABA-aminotransferase (GABA-T), succinic semialdehyde dehydrogenase (SDH) and succinate dehydrogenase (SSA-DH) was assayed. PCNs administration altered all examined activities in the selected brain areas, except GAD in basal ganglia. The results suggest the correlation between PCNs action and disturbance in GABA metabolism in rat brain. Moreover, the chronic PCNs intoxication increased SDH-mediated activation of TCA cycle, and it may be a kind of protective mechanism developed in nervous tissue in response to administration of toxic compounds.