title: Delayed alteration of membrane fluidity in intact cultured B-16 melanoma cells affected by ultraviolet irradiation.
abstract: Lipid peroxidation in the plasma membrane has been reported to decrease membrane fluidity. We examined membrane fluidity in relation to lipid peroxidation processes after UV-B exposure of cultured B-16 melanoma cells. UV exposure promptly increased TBA-positive material(s), but alteration of membrane fluidity was delayed. Plasma membrane fluidity increased significantly 6 hours after exposure when the TBA-value(s) had become under the control level. To examine the direct effect of lipid peroxides on the fluidity, tert-butyl hydroperoxide was added to B-16 melanoma cells. Similar results were obtained with respect to membrane fluidity. These results suggest that lipid peroxidation at UV doses maintaining cell viability does not directly induce a significant alteration of membrane fluidity, but may influence the fluidity either during metabolizing processes of UV-induced lipid peroxides or during repair processes following oxidative cell membrane damage.
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D007700:Kinetics; D008545:Melanoma / Q000378:metabolism*; D008560:Membrane Fluidity / Q000187:drug effects*; D051379:Mice; D010545:Peroxides / Q000494:pharmacology; D013113:Spin Labels; D014466:Ultraviolet Rays; D020122:tert-Butylhydroperoxide
chemical_list: D003497:Cyclic N-Oxides; D010545:Peroxides; D013113:Spin Labels; C037404:12-doxylstearic acid; D020122:tert-Butylhydroperoxide