Glial CellsCa2+ signaling regulated by an ATP-dependent autocrine mechanism in astrocytesShiga, Hatsuki; Tojima, Takuro; Ito, EtsuroCAAuthor Information Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan CACorresponding Author Received 2 May 2001; accepted 12 June 2001 Neuroreport: August 28th, 2001 - Volume 12 - Issue 12 - p 2619-2622 Buy SDC Abstract Although the mechanisms of Ca2+ wave propagation in astrocytes induced by mechanical stimulation have been well studied, it is still not known how the [Ca2+]i increases in the stimulated cells. Here, we have analyzed the mechanisms of [Ca2+]i increase in single, isolated astrocytes. Our results showed that there was an autocrine mechanism of Ca2+ regulation mediated by ATP in mechanically stimulated astrocytes. This autocrine mechanism induced the activation of phospholipase C via a G-protein, resulting in Ca2+ release from intracellular Ca2+ stores. A second pathway mediating a [Ca2+]i increase was via a Ca2+ influx from the extracellular space, which, interestingly, suppressed an intracellular Ca2+ oscillation. These two different Ca2+ cascades are involved in signal transduction and may function separately during intercellular communication. © 2001 Lippincott Williams & Wilkins, Inc.