Early polyribosomal and lysosomal changes in the liver of rats poisoned with Amanita phalloides or phalloidin.

30 min after poisoning with Amanita phalloides extract or phalloidin, rat liver polyribosomes appear strongly dissociated, and a small increase of free phosphatase activity is evident. A cycloheximide pretreatment prevents the polyribosome dissociation, without protecting against the lysosomal change. This indicates that the polysomal derangement is not due to a hydrolytic breakdown of messenger RNA. Phalloidin, added in vitro either to a liver cell-free system, or to isolated hepatocytes, does not inhibit their amino acid incorporating activity. The polysome dissociation, therefore, is dependent on changes induced by phalloidin when the liver cell is "in situ".