Ultrastructural observations of non-selective effects of ricin treatment (RCA-120) in the rat dorsal root ganglion.

The effects of ricin (RCA-120) on non-injected dorsal root ganglion (DRG) cells, sharing the same DRG as the injected ones, were studied after ricin injections into the tibial nerve and B-HRP injections into the peroneal nerve. Numerous DRG cells containing B-HRP reaction product and exhibiting signs of advanced degeneration were observed. The findings suggest that ricin may be released from dying injected DRG neurons and taken up by adjacent non-injected DRG cells, which subsequently degenerate.