A study on regional brain calcium concentrations following acute and prolonged administration of ethanol in rats

Abstract

Regional brain calcium concentrations were assessed after acute and chronic ethanol administration. Prolonged exposure to ethanol was accomplished by a 10-day inhalation procedure. Acute administration of ethanol in doses of 1.0, 2.0, and 3.0 g/kg failed to alter calcium content in the cerebellum, cortex, hypothalamus, midbrain, and pons-medulla 30 min after injection. However, ethanol at 4.0 g/kg reduced brain content in the hypothalamus, midbrain, and pons-medulla. When a 90-min interval between ethanol administration (2.0 g/kg) and sacrifice was used, no change was found in the calcium concentration of the five regions examined. During the induction of physical dependence on ethanol, no alteration in the brain calcium content was observed when compared with controls. In the withdrawal phase, which followed 10 days of ethanol inhalation, regional brain calcium concentrations were similar to control values. These animals were monitored up to 7 days postexposure. In experiments which involved acute administration of reserpine (5 or 10 mg/kg), it was shown that the 10 mg/kg dose decreased calcium content only in the hypothalamus by 19.6%. Based on the data derived from this investigation it appears that calcium ions may have a limited role, if any, in the central actions of ethanol when steady-state calcium ion concentrations are considered.