AbstractThe constituent proteins of the fast (110–150 mm/day) and slow (1.5–2 mm/day) components of axonal transport in the retinal ganglion cells of the rabbit were investigated. The fast and slow components were labelled by intraocular injection of (3H)‐ and (14C)‐leucine, respectively.Subcellular fractionation of the optic nerve and tract and subsequent gel electrophoresis of the fractions showed that most of the soluble proteins moved with the slow phase of axonal transport, whereas only some of the soluble proteins were transported with the rapid phase.Extraction of the microsomal fraction with triton X‐100 resulted in the solubilization of highly labelled proteins belonging to the rapid phase. These proteins showed a relatively low electrophoretic