Acute ethanol effects on focal cerebral ischemia in nonfasted rats

Focal cerebral ischemia was induced in a rat model of middle cerebral artery occlusion. Three groups of adult male Sprague-Dawley rats, given food and water ad libitum, were subjected to 4 hr of middle cerebral artery occlusion. All were given vehicle control and ethanol pretreatments intraperitoneally 1 hr before. Mean ipsilateral brain water content in the control, 2 g/kg ethanol, and 2 g/kg ethanol + insulin-treated groups showed: ischemia core: 81.1%, 82.5%, and 80.9%; intermediate zone: 81.0%, and 80.3%; and outer zone: 80.3%, 81.3%, and 80.1%, respectively. Brain Na+ and K4 content in these groups paralleled the water content. In addition to significantly (p < 0.05) more brain edema, the 2 g/kg ethanol-treated animal group also had significant hyperglycemia. In contrast, the 2 g/kg ethanol + insulin-treated animals were normoglycemic and had ischemic, intermediate, and outer zone Na+, K+, and Cl- levels comparable with the control group (p > 0.05). These results stress the importance of measuring and controlling plasma glucose levels in the in vivo studies of the neurotoxic effects of acute ethanol.