Anti-ricin antibody protects against systemic toxicity without affecting suicide transport

Ricin is an effective suicide transport agent which reliably destroys sensory and motor neurons in anatomically selective fashion after peripheral nerve application. In the present study, we gave subcutaneous injections of commercially available antiricin antibody (ARA) at the time of ricin application to peripheral nerves. The ARA protected rats against systemic ricin poisoning without altering the suicide transport activity of ricin. This approach removes a significant barrier to the routine use of ricin and should prove useful when ricin is employed to ablate large peripheral nerves. However, antibody protection permits use of such large ricin doses that the toxin may diffuse within the CNS destroying neurons adjacent to those that project through the injected nerve. Consequently, antibody and ricin doses must be optimized for any particular experimental situation.