Glycogenous hepatonuclear inclusions in the aged mouse--an electron microscopical study of the histogenesis of nuclear inclusions.

Fifty-three and 84 week old mice have been investigated for liver nuclear inclusions. Light microscopical investigations revealed a significantly higher incidence of intranuclear PAS-positive material in the 84 week old mice. Electron microscopical studies showed a continuous development of nuclear inclusions from invagination of the double nuclear membrane containing all cytoplasmic organelles in various conditions via isolation of the invaginated portion to intranuclear free glycogen as a visible final stage. During the whole process alpha-glycogen is degraded to beta- and gamma-particles. These nuclear changes are not accompanied by other pathological changes either in the cells concerned or in the surrounding liver parenchyma. These nuclear findings are attributed to specific metabolic conditions in the ageing mouse.