Abstract
We have investigated the relationship between Ca 2+ mobilization and the cellular production of nitric oxide (NO) by using fura-2 and diaminofluorescein-2 (DAF-2), an NO-sensitive dye, in bovine aortic endothelial cells (BAEC). High concentrations of ATP (100 μM) or thapsigargin (1 μM) depleted intracellular Ca 2+ store sites with a single Ca 2+ transient, and induced an increase in DAF-2 fluorescence even in Ca 2+-free solution, thereby indicating that store depletion leads to NO production. The same level of increase in DAF-2 fluorescence was elicited by low concentrations of ATP (1 μM), which induced Ca 2+ oscillations but did not deplete store sites, only in the presence of extracellular Ca 2+. Furthermore, inhibition of ATP (1 μM)-induced Ca 2+ entry with La 3+ suppressed DAF-2 fluorescence. ATP (0.3 μM), applied in Ca 2+-free, Mn 2+-containing solution induced Mn 2+ entry-coupled fura-2 quenching, repeating shortly after each oscillation peak. These results indicate that NO is produced preferentially by entered Ca 2+, and that Ca 2+ oscillations, which are induced by low levels of stimulation, play a significant role in NO production by strongly modulating Ca 2+ entry.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
