Acute alcohol decreases gangliosides in mouse brain.

We have reported that single doses of alcohol diminish total sialic acid in rat brain. Recent results indicate that this effect seems to be largely accounted for by alcohol-induced reduction in gangliosides. In these experiments, five replicate groups of mice were injected IP with a single dose of 20% alcohol and saline as control. At 1 hour postinjection, alcohol decreased total brain gangliosides (p less than 0.03) at 1 and 2 g/kg, but not at 3, 4, and 6 g/kg. Free whole-brain sialic acid was increased by 2 g/kg alcohol, which is consistent with the observed decrement in gangliosides at this dose. However, activity of sialidase on the endogenous substrates was not greatly affected by 2 g/kg of alcohol, indicating that ganglioside decrement is probably not attributable to activation of the catabolic enzyme. These results confirm and extend our earlier reports that incriminated gangliosides in the acute action of alcohol. The data also raise the possibility that the effect is due to the "excitatory," rather than the depressive actions of alcohol. Moreover, the action may involve an increased hydrolysis of membrane gangliosides by sialidase.