Release of Calcium from Intracellular Stores in Rat Basophilic Leukemia CellsMonitored with the Fluorescent Probe Chlortetracycline

摘要

Release of calcium from intracellular stores of rate basophilic leukemia cellswas monitored using the fluorescent probe chlortetracycline. The ability of chlortetracycline to indicate release from intracellular calcium stores was initially validated. The decrease of chlortetracycline fluorescence upon antigen-stimulation was not the result of secretion of granule-associated dye or of changes in the properties of the membranes. The chlortetracycline fluorescence signal was not influenced by Ca2+ influx across the plasma membrane. Results obtained from these chlortetracycline fluorescence measurements of release of calcium from stores. Chlortetracycline was used to examine the rate of antigen-induced release of calcium from stores, the depletion of intracellular calcium stores by EGTA, and the relationship between the antigen-simulated release of stored calcium and exocytosis. Chlortetracycline was shown to be a useful qualitative indicator for the release of intracellular calcium with a relatively rapid response time. Reprints. (JES)