title: Alteration of enzymes in ageing human fibroblasts in culture. III. Modification of superoxide dismutase as an environmental and reversible process.
abstract: The alteration of superoxide dismutase (SOD) defined as the change occurring in its thermostability and observed in ageing cells, concerned the cytoplasmic but not the mitochondrial enzymes. Altered SOD disappeared if it was incubated in a supernatant from the young cells whereas supernatants from the old cells induced the alteration. The alteration induced on purified SOD was found to be associated with the appearance of thermolabile tetramers. Cytoplasmic SOD tetramers were also observed in the supernatants of the old cells. The addition of NADPH into the incubation medium could reverse this alteration; also when cultivated in the presence of vincamine the alteration, normally present in the old cells, disappears. The alteration of SOD is therefore associated with the formation of tetramers; it is a reversible process influenced by the cytoplasmic composition of the old cells.
mesh_terms: D000375:Aging; D002470:Cell Survival; D002478:Cells, Cultured; D055598:Chemical Phenomena; D002621:Chemistry; D004777:Environment; D005347:Fibroblasts / Q000201:enzymology*; D006801:Humans; D013482:Superoxide Dismutase / Q000378:metabolism*; D014749:Vincamine / Q000494:pharmacology
chemical_list: D014749:Vincamine; D013482:Superoxide Dismutase