Ricin consists of two hemagglutinins and two toxins. These toxins are dimers consisting of cytotoxic A chains and B chains which serve as transport peptides and bind to cellular membrane receptors. Ricin toxins are potent inhibitors of DNA replication and protein synthesis. Transmission has been by inhalation of organism during industrial operations. Also, transmitted through ingestion of castor bean meal.
Clinical features vary according to the route of intoxication and toxin dose.
Patients presented with acute onset of fever, chest tightness, cough, dyspnea, nausea, and arthralgias 4 to 8 hours after exposure. The onset of profuse sweating several hours later was the sign of termination of most of the symptoms. Ingestion results in necrosis of the GI epithelium, local hemorrhage, and hepatic, splenic, and renal necrosis. Intramuscular injection results in severe local muscle necrosis and visceral organ involvement. The University of Iowa.