The use of anti-ricin antibodies to protect mice intoxicated with ricin.

Antibodies raised in rabbits to ricin or its constituent polypeptide chains are effective at rescuing mice from ricin intoxication if given soon enough after administration of the toxin. The maximum safe period for intravenous injection of 100 micrograms antibody is 40 min after intravenous injection of 1 microgram ricin, increasing to 640 min in the case of subcutaneously injected ricin. The antibodies raised against the isolated A and B chains are as effective as those against whole ricin. The antibody is as effective when administered intracerebrally as by the intravenous route; this result, combined with the very high toxicity for ricin administered intracerebrally suggests a neurotoxic role for the lectin.