Age-related alterations in the size of human hepatocytes

Summary

Age-related alterations in the size of human hepatocytes (both mononudear and binucieate forms), were studied in histological sections and in separated cells and nuclei using cytophotometrical and microspectro-photometrical methods. The following results were obtained : 1. The volume of nuclear DNA increased in proportion to nuclear size. The increase occurred in a group pattern reflecting nuclear polyploidization. 2. Cell size increased in proportion to nuclear size. Tetraploid cells (4C) were roughly two times greater than diploid cells (2C). 3. In most of the binucieate cells examined, the ploidy class of the two nuclei in a binucieate cell was observed to be equal. Heterogeneity of the ploidy class among the nuclei of a binucieate cell was present in less than 1% of total binucieate cells examined. The nuclear DNA volume of individual nuclei in binucieate cells appeared to be the same as that of mononuclear cells. 4. The cell size of binucieate cells corresponded with that of mononuclear cells whose ploidy class was the same as the sum of the ploidy classes of two nuclei of a binucieate cell. 5. The incidence of binucieate cells in the lobular periphery was about 4 to 6% in the third decade, and increased slightly with age up to 5 to 7% in the tenth decade. 6. The incidence of binucieate cells in the liver at different ages followed a similar pattern to that observed in mononudear cells whose ploidy class was half of the sum of ploidy classes of the two nuclei of the binucieate cell.