Acrylamide-induced Changes in the Neurofilament Protein of Rat Cerebrum Fractions

Acrylamide (ACR) is known to produce central-peripheral distal axonopathy, which is characterized by distal swellings and secondary degeneration both in experimental animals and human. Ultrastructurally, excessive accumulation of neurofilaments (NFs) in the distal swollen axon is a major pathological hallmark. However, the mechanisms of ACR axonopathy remain unknown. Twenty seven male Wistar rats were randomly divided into three groups. Lower and higher ACR groups were received 20 and 40 mg/kg ACR by i.p. injection respectively. The control group received physiological saline. All rats were sacrificed after 8 weeks of treatment and their cerebrums were dissected, homogenized and used for the determination of the NF proteins. In general, the levels of light NF (NF-L) and medium NF (NF-M) subunits increased consistently in the supernatant, whereas they decreased consistently in the pellet from rats treated with ACR. Compared to that of the control group, the levels of NF-L increased respectively by 104% and 45% (P<0.01) in the supernatant and decreased by 16% and 11% (P<0.01) in the pellet of rat cerebrums in lower and higher groups. The enhancement of NF-M was 76% and 147% (P<0.05, P<0.01) in supernatant, and the reduction was 26% and 36% (P<0.01) in pellet in lower and higher group respectively. The heavy NF (NF-H) level changed slightly. The present results suggested that the change of NF-L and NF-M levels in cerebrum might be relevant to the mechanisms of the neurofilamentous axonopathies induced by ACR.