title: Alterations in superoxide dismutase, glutathione, and peroxides in the plasmodial slime mold Physarum polycephalum during differentiation.
abstract: Changes in the level of antioxidant defenses and the concentration of free radical by-products were examined in differentiating (M3cVII and LU897 X LU863), non-differentiating (LU887 X LU897), and heterokaryon microplasmodia of the slime mold Physarum polycephalum during spherulation in salts-only medium. As differentiation proceeded, superoxide dismutase activity increased by as much as 46 fold; glutathione concentration and the rate of oxygen consumption decreased; cyanide-resistant respiration, hydrogen peroxide, and organic peroxide concentrations increased. The non-differentiating culture failed to exhibit any of these changes. A heterokaryon obtained by the fusion of differentiating and non-differentiating strains was observed to differentiate at a very retarded rate and to exhibit the changes observed in the spherulating strains at a correspondingly slower rate. These observations suggest that a free radical mechanism may be involved in the differentiation of Physarum microplasmodia into spherules.
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D003470:Culture Media; D005978:Glutathione / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008054:Lipid Peroxides / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D010804:Physarum / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D011190:Potassium Cyanide / Q000494:pharmacology; D012492:Salts / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D003470:Culture Media; D008054:Lipid Peroxides; D012492:Salts; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D005978:Glutathione; D011190:Potassium Cyanide