Disturbances of karyokinesis and its relation to the nuclear pattern

The main causes of mitotic disturbances of spindle formation and inadaequate development of the mitotic apparatus. Quantitatively of the greatest importance in both groups are collapse of the prophase and failure of cytokinesis, respectively. The division of polyploid nuclei is, in addition, complicated by alterations of multicentric spindles. Results of mitotic disturbances are changes in the degree of ploidy of cells or nuclei. In irreversible post-mitotic tissues these occur already in the growth phase, as is shown in the example of the heart. In reversible post-mitotic tissues these changes in the degree of ploidy modify the nuclelar pattern predominantly during the processes of ageing, reparation and regeneration, as is well documented in the liver.