Nucleolar reorganization in liver cells of the aging rat

Journal of Morphology
F B Adamstone, A B Taylor

Abstract

The nucleoli of rat liver cells duplicate in great detail the life-long series of reorganizational changes encountered in kidney and intestinal epithelial cells. The ultrastructural components of the large, loosely organized polymorphous nucleoli, which are dominant in the rapidly multiplying stem cells of embryos, are readily accessible for chemical activities. Smaller, more compact amphinucleoli are dominant in more mature cells, which were characterized by Smetana ('70) as "idling" cells, showing slowly continuing ribosome formation and RNP synthesis. In older cells bipartite nucleoli become dominant and are reorganized in increasing numbers from the younger amphinucleoli. These, however, are not replaced in equal numbers from the shrinking pool of polymorphs of young cells which have greatly reduced mitotic potential. Paralleling the shifts in dominant nucleolar types, the high level of protein synthesis declines in older cells not only in the quantity of proteins synthesized but also in kinds of enzymes produced. These fail to meet the structural and functional requirements of aging cells leading ultimately to the onset of age-related degenerative changes. Again it is noted that separation of the karyosomal DNA from the pl...Continue Reading

References

Dec 1, 1977·Journal of Morphology·F B Adamstone, A B Taylor
Feb 1, 1972·Journal of Morphology·F B Adamstone, A B Taylor
Dec 1, 1972·The Australian Journal of Experimental Biology and Medical Science·H Harris
Oct 1, 1973·Experimental Gerontology·D E Buetow, P S Gandhi
Jan 1, 1970·International Review of Cytology·R Simard
Mar 1, 1972·Journal of Ultrastructure Research·J K Reddy, D J Svoboda
Apr 1, 1970·Journal of Gerontology·M A Gibas, D Harman
May 1, 1970·Experimental Cell Research·K SmetanaH Busch
Sep 1, 1970·Experimental Gerontology·M S KanungoK R Reddy
Sep 15, 1966·International Journal of Cancer. Journal International Du Cancer·R Simard, W Bernhard
Jan 1, 1962·The American Journal of Anatomy·W ANDREW
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Mar 1, 1948·The Anatomical Record·C P LEBLOND, C E STEVENS

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