The Kupffer cell is the first target in ricin-induced hepatitis.

The first target of ricin in the liver appears to be the Kupffer cells which are heavily damaged as early as four hours after the intravenous inoculation of 6 LD100 into mice. At that time, the only endothelial cell damage is constituted by more or less extended interruptions of the fenestrated cytoplasm. Hepatocyte injury affects the endoplasmic reticulum, the glycogen, the mitochondria as well as the plasmic membrane; however, it never results in cytolysis or complete necrosis. The intravascular coagulation observed may be induced either by the endotoxins, which are no longer cleared by the Kupffer cells, or as a result of the loss of the sinusoidal lining with the ensuing platelet activation.