title: Morphological changes in aging cell lines of Paramecium aurella. I. Alterations in the cytoplasm.
abstract: Electron microscopical examination of aging P. aurelia revealed that definitive changes occur in the cytoplasm of old cells. There was an increase in the number of mitochondria and lysosomal bodies as well as the appearance of large dense bodies and autophagous vacuoles. The mitochondria were altered morphologically and many appeared to be coalesced with lysosome-like bodies and were also observed to be degenerating within autophagous vacuoles. The large dense bodies were considered to be similar to the lipofuscin or age pigments reported in other aging cells. The relationship of the large dense bodies to the lipofuscin pigments and their probable origin are discussed as is the involvement of the cytoplasm in the aging death process in P. aurelia.
mesh_terms: D000375:Aging; D000818:Animals; D002460:Cell Line; D003593:Cytoplasm / Q000502:physiology / Q000648:ultrastructure*; D008062:Lipofuscin; D008247:Lysosomes / Q000502:physiology / Q000648:ultrastructure; D008928:Mitochondria / Q000502:physiology / Q000648:ultrastructure; D010247:Paramecium / Q000502:physiology / Q000648:ultrastructure*; D010860:Pigments, Biological
chemical_list: D008062:Lipofuscin; D010860:Pigments, Biological