Acrylamide neuropathy: changes in the composition of proteins of fast axonal transport resemble those observed in regenerating axons.

Proteins conveyed by fast axonal transport along sensory and motor axons of rat sciatic nerve were labelled with L-[35S]methionine and characterized by one- and two-dimensional electrophoresis on polyacrylamide gels, followed by fluorography. Nerves from normal or bis-acrylamide-treated animals were compared with nerves from acrylamide-treated animals and nerves regenerating after a crush axotomy. In both sensory and motor axons significant changes in the pattern of labelled bands on one-dimensional gels occurred after 10 days of acrylamide treatment (50 mg/kg daily, i.p.). These changes resembled those seen in regenerating axons, but were less pronounced. No changes were detectable after shorter periods of treatment, even though the onset of the neuropathy, assessed by a behavioral test, occurred on days 4-6 of treatment. Two-dimensional separations of the labelled proteins revealed increased labelling of growth-associated protein 43 in acrylamide-treated animals, but again this was less pronounced than in regenerating nerves. Acrylamide treatment induces changes in composition of fast-transported protein that are qualitatively similar to those seen after axotomy. Since these changes are not detectable until the neuropathy is advanced, it is unlikely that they are causative factors. Instead, they are most likely a result of the cell body reaction previously observed in acrylamide intoxication, a reaction that resembles that produced by axotomy.