Acrylamide alters oxidative enzyme activity in rat motoneurons

Acrylamide (ACR) produces a central-peripheral distal axonopathy, via an unknown mechanism. We have investigated the effects of ACR on the activity of enzymes responsible for the oxidation of NADH (NADH-tetrazolium reductase activity, NADH-TR) with quantitative histochemical techniques. Chronic (5- or 10-day) injection of ACR (50 mg/kg/day) resulted in a significant decrease in enzyme activity in soleus motoneurons, which normally have high NADH-TR activity. The NADH-TR activity in motoneurons with low oxidative metabolism was not significantly affected. Retrograde labeling of motoneurons with horseradish peroxidase was diminished by the acrylamide treatment. These data demonstrate an acrylamide-induced change in the oxidative metabolism of certain motoneurons; further study will determine whether oxidative metabolism is the primary site of action of ACR in producing the distal axonopathy.