Effect of ricin on acute phase response in rats.

Ricin, a highly toxic protein from castor beans was administered (ip) to rats in a dose of 1.25 micrograms/100 g to selectively deplete at least 60-70% of Kupffer cells. This dose spared hepatocytes. This rat model was used to study acute phase protein synthesis and the role of Kupffer cells in acute phase response (APR). Ricin itself induced an APR, similar in pattern but of lower magnitude, than that induced by turpentine. However, the effect of combination of ricin and turpentine on APR was not additive. Kupffer cells appear to play permissive role in APR through mediators like hepatocytes stimulating factors.