Characterization of amyloid of ageing obese-hyperglycaemic mice and their lean littermates.

Amyloid fibrils, isolated from 18-month-old obese-hyperglycaemic mice and their lean littermates, were characterized immunologically and chemically. The main amyloid fibril subunit protein was protein AA, which cross-reacted completely with an antiserum against amyloid from mice with experimentally induced amyloidosis and had an amino acid composition and N-terminal amino acid sequence identical to that protein. These results indicate that the spontaneously occurring amyloidosis in obese-hyperglycaemic mice and their lean littermates corresponds to human, secondary amyloidosis and may serve as a model for that disease.