Alterations in rat brain polyphosphoinositide metabolism due to acute ethanol administration.

The effects of acute ethanol administration on the polyphosphoinositide metabolism of rat brain cerebral cortex were examined. Intracerebral injections of [gamma-32P]ATP proved to be an effective in vivo method to prelabel brain phospholipids, especially the polyphosphoinositides. High acute doses of ethanol (8 or 6 g/kg b.wt.) administered by gavage significantly inhibited the breakdown of polyphosphoinositides as judged by an elevation in the concentration as well as the labeling of these compounds. Concomitantly, there was a significant reduction in the level of diacylglycerols. Low acute doses of ethanol (2 g/kg b.wt.) did not seem to have any effects on the basal levels or labeling of these compounds. The changes in polyphosphoinositide labeling due to ethanol intoxication were reverted to near control values when animals regained their righting reflex (approximately 4 hr). These studies demonstrate that, under normal conditions, polyphosphoinositides and diacylglycerols are maintained in a dynamic equilibrium and that acute doses of ethanol can suppress the signal transduction process and disturb this equilibrium.