Amyloid A proteins in different species.

Amyloid A (AA) proteins were purified from canine and bovine idiopathic amyloid and casein-induced hamster amyloid. The molecular weights of these proteins were in the same range (8,000-10,000) as those reported for AA proteins from man and other animal species. The amino acid compositions were comparable as well. Antisera against human, bovine, canine and hamster protein AA were tested with the indirect immunoperoxidase antiperoxidase (PAP) method and the indirect immunofluorescence technique on amyloid-containing human, bovine, canine and hamster tissue sections. Antihuman protein AA serum did not cross-react with hamster protein AA. In all the other combinations, cross-reactions were observed. Because of the high similarity of these different AA proteins, the amyloid diseases in the species mentioned can serve as interchangeable models to investigate the pathogenesis of AA amyloidosis.