Alcohol acutely depresses myo-inositol 1-phosphate levels in the male rat cerebral cortex.

The effects of acute alcohol administration on myo-inositol and myo-inositol 1-phosphate levels in the male rat cerebral cortex were examined. At a dose of 3 g/kg, alcohol reduced myo-inositol 1-phosphate levels in the cortex by 60% within 30 min after its injection. A significant depression in myo-inositol 1-phosphate was found 5 min after the injection of alcohol, and maximal levels of depression occurred at 30 min. Levels of myo-inositol 1-phosphate remained significantly depressed for 6 hr and then gradually recovered, reaching normal values of 24 hr after the initial injection. There was an excellent inverse correlation (rxy = 0.96) between myo-inositol 1-phosphate levels and blood alcohol levels at all time intervals examined. Dose-response analyses indicated that the half-maximal (ED50) decrease in myo-inositol 1-phosphate levels occurred at a dose of 1.6 g/kg of alcohol. In contrast to these effects, myo-inositol levels were not significantly altered by any dose of alcohol at any time interval examined. Because of the rapidity of changes in myo-inositol 1-phosphate after acute alcohol administration and the excellent negative correlation between blood alcohol levels and changes in myo-inositol 1-phosphate, alcohol-induced alterations in myo-inositol 1-phosphate appear to be the direct effect of alcohol per se and may participate in the acute pharmacological effects of the drug.