The Toxicology of Ricin and Abrin Toxins - Studies on Immunisation Against Abrin Toxicity
Abstract
The toxicology of ricin and abrin toxins has been examined in rats by head only exposure to a range of concentrations, generated from solution as aerosols of mmad 0.9 micrometers. The approximate LCt(50)s were determined for each toxin and found to be very similar (LCt(50 ricin 4.54-5.96, abrin 4.54 mg. min.m-3). In both cases pathology was found to be restricted to the lung and included necrosis of lower airway epithelium, degeneration of type I pneumocytes accompanied by severe interstitial and intra-alveolar oedema; this feature, accompanied by hypoxia, was the cause of death. The recovery phase was typified by hyperplasia of type II epithelial cells (particularly florid for abrin) and gradual disappearance of protein-rich alveolar oedema fluid. From studies performed in vitro using bovine pulmonary endothelial cells, inhibition of protein synthesis occurred from 30 minutes incubation with abrin or ricin (LC(70) concentrations) while decrease in viability did not occur until. between 15 and 24 hours under the same conditions. Given this information, the time frame for therapeutic intervention is likely to be small and therefore immunisation would appear to be the best option for protection against abrin or ricin toxicity. We have examined the efficacy of immunisation with abrin toxoid in the rat in terms of immune-status and effect of subsequent challenge with multiple LCt(50)s of the native toxin.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 13, 1993
- Accession Number
- ADP008895
Entities
People
- Christopher D. Lindsay
- David G. Upshall
- Gareth D. Griffiths
- Paul Rice