The role of changes in the cytoplasmic concentration of Ca2+ in dexamethasone-induced thymocyte death
Kotelevskaia, S.M.; Zinchenko, V.P.; Petruniaka, V.V.; Korystov, I.N.; Shaposhnikova, V.V.; Kruman, I.I.; Gukovskaia, A.S.
Tsitologiia 33(11): 166-171
1991
ISSN/ISBN: 0041-3771 PMID: 1819172 Document Number: 382195
The putative role of changes in cytosolic Ca2+ concentration ([Ca2+]i) in the dexamethasone (DM) induced thymocyte death was investigated. Incubation of rat thymocytes with 10(-7) M DM for different time intervals from 0.1 to 8 h did not change the basal [Ca2+]i level ca 100 nM as measured with Ca(2+)-fluorescent probe Quin-2. Ca2+ influx measured by the rate of 45Ca2+ uptake was also just the same in DM treated and control cells. At the same time a 6-8 h incubation of cell suspension with 10(-7) M DM results in significant increase in DNA fragmentation and pyknosis, and a 24 h incubation is associated with the decrease in the percentage of cells not staining with Trypan blue. Thus, the results obtained indicate that 10(-7) M DM induces thymocyte death without any significant and constant [Ca2+]i rise during the first 8 h after hormone application.