Lethal retrograde axoplasmic transport of doxorubicin (adriamycin) to motor neurons. A toxic motor neuronopathy.

Doxorubicin (Adriamycin) is an autofluorescent anthracycline antibiotic that acts as a DNA intercalator. Following intraneural microinjection of 3 micrograms of doxorubicin into rat tibial nerve, fluorescence microscopy indicated that it is transported retrogradely to anterior horn cell bodies. Subsequently, these motor neurons underwent a progressive subacute degeneration that occurred over a period of 35-39 days. Combined electrophysiological and neuropathological methods indicated that dorsal root ganglion cells were relatively unaffected by this dose of toxin. The selective motor neuron degeneration produced by this agent raises the possibility that abnormalities of nucleic acid metabolism may be involved in the aetiology of motor neuron diseases.