Fluorescent lipid probes 12-AS and TMA-DPH report on selective, purinergically induced fluidity changes in plasma membranes of lymphoid cells.

摘要: The effect of extracellular ATP (ATPex) on the anisotropy 1-[4-(trimethylamino) phenyl]-6-phenyl-hexa-3,5 triene (TMA-DPH) and 12-anthroyloxi-stearic acid (12-AS) fluorescence was investigated in Balb/C mouse thymocytes JY human lymphoblasts. These cells have been shown recently to be sensitive resistant ATPex, respectively, terms cellular responses. Extracellular (1 mM) induced a time-dependent elevation emission both probes (indicating an increased lipid packing density) plasma membrane thymocytes. maximal effect, at 37 degrees C, observed between 20 60 min after ATPex administration, followed by gradual decrease longer times (60-180 min). did not change fluidity below phase transition temperature (at 18 C). Oxidized (oATP), selective antagonist P2z purinoreceptors, blocked ATPex-induced fluidity. Low concentrations (100-300 microM)--which are known induce distinct signals (changes potential intracellular Ph)--slightly fluidized This partially quinine, blocker Ca(2+)-activated K+ channels. Neither 12-AS nor TMA-DPH showed any their upon ATPex-treatment lymphoblast cells. No other signalling event (membrane change, Ca2+ response) is elicited this cell line. data suggest that changes likely consequences specific, purinoreceptor-mediated events, such as hyper-or depolarization or influx. may conformation lateral organization proteins, perturbing protein-lipid interactions, well.