Amyloidosis in ageing obese-hyperglycemic mice and their lean litter-mates. A morphological study.

The occurrence of amyloidosis in obese-hyperglycemic mice (genotype obob) about 18 months old and their lean litter-mates was studied. Amyloidosis of varying degrees was found in 60 per cent of the mice and was equally common in both groups. Large amounts of amyloid were usually seen in the adrenal glands, liver, spleen and kidneys. In the kidneys, the amyloid was found mainly in the glomeruli, in the mesangial region. Electron microscopy of isolated amyloid fibrils showed that these consisted of two filaments about 40 A thick, twisted around each other. It is concluded that the distribution of the amyloidosis in these mice is similar to that seen in secondary or experimental murine amyloidosis.