Intraventricularly applied D-galactosamine inhibits the incorporation of [(3)H]-fucose into rat brain glycoproteins.
In the rat, intraventricularly applied D-galactosamine (GalN) (10 or 20 mumoles) inhibited [(3)H]-fucose incoporation into hippocampal and subcortical glycoproteins by appr. 50% of the controls. The inhibitory effect occurred within 40 min after GalN administration and did not reach normal values even 16 h upon GalN injection. During the first hours upon GalN administration the inhibition of fucose incorporation involved predominanatly water-soluble and Triton-soluble glycoproteins, whereas the Triton-resistant fraction showed a delayed suppression. The results suggest that GalN suppresses the formaton of membrane glycoproteins (because only 15% of fucose radioactivity remained in water-soluble fraction) which are believed to play an essential role in formation of long-term memory. Under these aspects, the amnesic effect of GalN on the retention of a brightness discrimination and the abolishment by uridine treatment, as observed in our laboratory, may be interpreted as a further support to the particular role of glycoproteins in the consolidation of a memory trace.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D005643:Fucose / Q000378:metabolism*; D005688:Galactosamine / Q000494:pharmacology*; D006023:Glycoproteins / Q000096:biosynthesis*; D006624:Hippocampus / Q000378:metabolism; D007276:Injections, Intraventricular; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis; D051381:Rats; D013788:Thalamus / Q000378:metabolism; D014018:Tissue Distribution
D006023:Glycoproteins; D008565:Membrane Proteins; D005643:Fucose; D005688:Galactosamine