PHOTODYNAMIC-ACTION OF MEROCYANINE-540 ON PLASMA-MEMBRANE OF GLIOBLASTOMA CELLS

Structural modifications in plasma membrane of human glioblastoma cell s induced by photodynamic action of merocyanine 540 (MC540) were inves tigated using lipid and protein specific fluorescent probes. Photoirra diation of MC540 treated cells caused a decrease in the steady state a nisotropy, decay time,limiting anisotropy and order parameter with an increase in the cone angle and rotational relaxation time of trimethyl ammonium 1,6-diphenyl-1,3,5-hexatriene (TMA-DPH). Increase in the lipi d peroxidation, loss of SH groups, increase in the relaxation time of N-(1-Pyrene)-maleimide (PM) and cross linking of proteins were also ob served on photosensitization of cells. These results suggest that phot osensitization alters the structural organization of plasma membrane o f glioblastoma cells. Copyright (C) 1997 Elsevier Science Ltd.