3-O-methyl-D-glucose and beta-alanine: rapid axoplasmic transport of metabolically inert low molecular weight substances.

The dynamics of the axoplasmic transport of free beta-alanine and 3-O-methyl-D-glucose were quantitatively characterized in vivo in the pike olfactory nerve following intranasal application of the tritiated substances. Both compounds were found to be taken up by the epithelium but not metabolized to a significant extent. Axoplasmic transport showed the same dynamics as rapid transport of protein and free leucine in this nerve. No synthesis or transport of carnosine was detectable. The results are in agreement with the view that rapid axoplasmic transport is capable of conveying free, low molecular weight molecules in a non-specific manner.