In vivo binding of [(14)C]acrylamide to proteins in the mouse nervous system

The labeling of mouse brain and spinal cord proteins in vivo following the administration of 200 ?g/kg [(14)C]acrylamide (25 mCi/kg, i.p.) was measured by polyacrylamide gel electrophoresis and autoradiography. Several cytoskeletal proteins had the highest specific activity. These included the medium (130 kDa) and high (180 kDa) molecular weight neurofilament proteins and unknown proteins with molecular weights of 31, 33 and 57 kDa. About 0.05% of the neurofilament proteins were labeled with the dose employed. Although accurate assessments of the stoichiometry for acrylamide binding to 31, 33 and 57 kDa bands could not be made due to the low concentrations of these proteins, it is estimated that over 0.1% of these proteins bound acrylamide. There were significant amounts of acrylamide bound to proteins seven days after exposure, with labeling ranging from 15 to 60% of the levels observed one day after exposure. These results show that acrylamide binds to several major cytoskeletal proteins present in the mouse nervous system. The formation of these adducts may play a role in the neurotoxicity of acrylamide.