Experimental treatment of neuromas in the rat by retrograde axoplasmic transport of ricin with selective destruction of ganglion cells.

In this experiment the toxic lectin, ricin, was injected into the terminal proximal segment of transected rat sciatic nerves to evaluate its effect on neuroma formation. The dosage of ricin injected ranged from 0.5 microgram to 1.5 micrograms. All animals survived and all treated nerves showed no evidence of neuroma formation and no evidence of viable nerve elements 1 month after treatment. The contralateral untreated nerves in the experimental groups, as well as those of the control group, all showed neuroma formation. This study demonstrates the effectiveness of small doses of ricin in preventing neuroma formation in rats. The mechanism of action of ricin, destruction of the parent ganglion cells of the treated peripheral nerves after its retrograde axoplasmic transport, is also demonstrated.