EFFECTS OF 6 WEEKS OF CHRONIC ETHANOL ADMINISTRATION ON LACTIC-ACID ACCUMULATION AND HIGH-ENERGY PHOSPHATE LEVELS AFTER EXPERIMENTAL BRAIN INJURY IN RATS

The effects of 6 weeks of chronic ethanol administration on the latera l fluid percussion (FP) brain injury-induced regional accumulation of lactate and on the levels of total high-energy phosphates were examine d in rats, In both the chronic ethanol diet (ethanol diet) and pair-fe d isocaloric sucrose control diet (control diet) groups, tissue concen trations of lactate were elevated in the cortices and hippocampi of bo th the ipsilateral and contralateral hemispheres at 5 min after brain injury. In both diet groups, concentrations of lactate were elevated o nly in the injured left cortex and the ipsilateral hippocampus at 20 m in after FP brain injury. No significant differences were found in the levels of lactate in the cortices and hippocampi of sham animals and brain-injured animals between the ethanol and control diet groups at 5 min and 20 min after injury. In the ethanol and control diet groups, tissue concentrations of total high-energy phosphates (ATP + PCr) were not affected in the cortices and hippocampi at 5 min and 20 min after lateral FP brain injury, No significant differences were found in the levels of total high-energy phosphates in the cortices and hippocampi of the sham and brain-injured animals between the ethanol and control diet groups at 5 min and 20 min after injury, Histologic studies reve aled a similar extent of damage in the cortex and in the CA3 region of the ipsilateral hippocampus in both diet groups at 14 days after late ral FP brain injury, These findings suggest that 6 weeks of chronic et hanol administration does not alter brain injury-induced accumulation of lactate, levels of total high energy phosphates, and extent of morp hological damage.