Tissue sections of senescence-accelerated mice (SAM) and of mice with normal aging characteristics (R series) were studied using a
peroxidase-antiperoxidase (PAP) method with specific
antisera against a unique
amyloid fibril protein (AS/SAM) and against murine
protein AA. Anti-
AS/SAM antisera reacted with
amyloid tissues of SAM and aged R series mice but not with normal tissues or
amyloid tissues containing
protein AA. Reactivity of this and serum could be abrogated by absorption with purified
AS/SAM.
Amyloid deposits in liver, kidney, spleen, gastrointestinal tract, lung, heart, gonads, pancreas, salivary glands, adrenal, thyroid, skin epineurium, and blood vessels were positive for
AS/SAM in both the SAM and R series. Brain and bone medulla, however, were not stained. The
amyloid deposited in gonads, papillary layer of dermis, and epineurium was exclusively
AS/SAM. The
amyloid observed in most of the P-1 series mice was
AS/SAM. In the
P-2 series and R series,
protein AA frequently coexisted with
AS/SAM as demonstrated using a double staining method. Each
amyloid localized preferentially in the liver, spleen, and gastrointestinal tract.