Effect of acute injections of ethanol on lipid and protein-bound sialic acid in mice of different ages

Abstract

Mice of different age groups (weanling, young adult and aged) were tested for changes in brain lipid- and protein-bound sialic acid (SA) 2 h after ethanol (2 g/kg, i.p.), either as a single dose or after binge dosing of five repeated doses of ethanol spaced 2 h apart. The results clarify our earlier demonstrations that acute ethanol can reduce whole brain SA. Ethanol generally decreased SA of both gangliosidic and glycoprotein origin, with the effect varying with number of doses and mouse age. Single-dose ethanol decreased both lipid-bound and protein-bound SA in young adults and decreased lipid-bound SA in aged mice. There was no effect on lipid-bound SA in weanlings, but weanlings did have a 72% decline in protein-bound SA. Repeated injections in young adults did not cause the SA decrease seen with acute injection. In both weanling and aged mice, however, repeated injections did cause large decreases in both lipid- and protein-bound SA. Small, but statistically significant, changes also occurred in free SA. Ethanol increased free SA in singly-dosed young adults and in multiply-dosed aged adults, while causing a distinct decrease in singly-dosed weanlings.