Senile amyloidosis and neuron binding antibody in the aging Syrian hamster

The effects of age, sex, and irradiation on the genesis of amyloidosis, neuron-binding antibody (NBA), and the concomitant appearance of these two phenomena were studied in a colony of Syrian hamsters. In nonirradiated controls amyloidosis increased in prevalence with age after 12 months, and prevalence was higher in females than in males. Irradiation had the effect of advancing the appearance of amyloidosis to the 7-12 months group but did not intensify the amyloidotic process. IgG binding to the nucleus or cytoplasm of neurons was rare, and, despite the fact that IgM and IgA binding to these structures was present in about one-third of the animals, there was neither an aging nor an irradiation effect. The only statistically significant findings with respect to the concomitant occurrence of amyloid and NBA were negative correlations between nuclear IgM and IgA binding and amyloidosis. Of the various species thus far studied, the hamster is the first in which there has been no aging effect in respect to NBA.