Antigen-triggered membrane potential changes in IgE-sensitized rat basophilic leukemia cells: evidence for a repolarizing response that is important in the stimulation of cellular degranulation.

摘要: We have studied Ag-induced membrane potential changes of rat basophilic leukemia cells by using the potential-sensitive dye, bis-(1,3-diethylthiobarbiturate)trimethineoxonol. A rapid depolarization is triggered a multivalent Ag, and it has bell-shaped dose dependence that parallels degranulation response but not extent cross-linking IgE-receptor complexes. As temperature reduced from 37 degrees C, this slows decreases in magnitude until complete inhibition observed at 15 similar to previously for Ag-stimulated rise cytoplasmic Ca2+ degranulation. The results imply highly temperature-dependent step subsequent Ag binding necessary response. partial return resting seen follow Ag. This repolarization process inhibited quinidine.HCl Ba2+ parallel with an Repolarization affected 4-aminopyridine or absence K+ external buffer. These data suggest caused uncharacterized channel.