Changes in membrane fluidity associated with lymphocyte stimulation by succinyl-concanavalin A.
Time-resolved fluorescence anisotropy studies of human peripheral blood lymphocytes labeled with 1,6-diphenyl-1,3,5-hexatriene were carried out at temperatures between 4 and 38 degrees C. For unstimulated freshly-isolated lymphocytes the calculated order parameters were found to be 0.62 at 4 degrees C and 0.44 at 37 degrees C. Mitogen-induced alterations in the order parameter were evident within minutes after addition of succinyl-concanavalin A to the cells, increasing to a value of 0.56 after 2 h at 37 degrees C. Both stimulated and unstimulated cells show a decrease in fluorescence anisotropy over the next 2-3 days of culture and after the third day the time-resolved fluorescence anisotropy decay profiles of the two populations of cells were indistinguishable. Our results indicate that there are both short- and long-term changes in the membranes of the cell upon stimulation by mitogen.
D000328:Adult; D002462:Cell Membrane / Q000187:drug effects; D003208:Concanavalin A / Q000031:analogs & derivatives* / Q000494:pharmacology; D004161:Diphenylhexatriene; D005454:Fluorescence Polarization; D006801:Humans; D007700:Kinetics; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000187:drug effects; D008560:Membrane Fluidity / Q000187:drug effects*; D013696:Temperature
D003208:Concanavalin A; D004161:Diphenylhexatriene; C019558:succinylconcanavalin A