CHRONIC ETHANOL INGESTION-INDUCED CHANGES IN OPEN-FIELD BEHAVIOR AND OXIDATIVE STRESS IN THE RAT

The effects of chronic ethanol intoxication on the open-field behavior , on antioxidant enzyme activities, and the degree of lipid peroxidati on were investigated. Rats consuming a liquid diet containing 7% ethan ol for 4, 7, 14, or 21 days exhibited a significantly decreased ambula tion activity, accompanied by a reduced frequency and duration of expl orative rearing in an open-field task 4, 7, and 14 days after chronic ethanol ingestion, whereas presumed adaptation to the neurologic effec ts of ethanol was observed on day 21. Changes in the activities of glu tathione peroxidase (GSH-Px), glutathione reductase (GSH-R), and catal ase, and in the content of reduced glutathione (GSH) in blood samples were determined by means of biochemical methods. The degree of lipid p eroxidation was measured via thiobarbituric acid assays. Chronic ethan ol ingestion elicited a significant. increase in GSH-Px activity (by a maximum of similar to 32% on day 14), whereas opposite alterations in GSH-R and catalase activities were recorded (49% of the control value on day 4 and 17% on day 21, respectively). Highly elevated contents o f thiobarbituric acid reactive substances reflected extensive lipid pe roxidation processes throughout the experiment. These changes indicate that ethanol toxicity induces profound changes in explorative behavio r, mediated, at least partly, by changes in the free radical metabolis m. (C) 1997 Elsevier Science Inc.