The net content of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] was measured in bradykinin (BK)-stimulated NIH3T3 fibroblasts and neuroblastomaglioma hybrid cells (NG108-15). BK-mediated production of Ins(1,4,5)P3 was not affected by replacing the medium with Ca2+-free medium, but addition of EGTA(1mM) to Ca2+-free medium markedly prevented production of Ins(1,4,5)P3. Although perussis toxin (PT) treatment caused ADP-ribosylation in both N1H3T3 cells and NG108-15 cells, the BK-induced Ins(1,4,5)P3 formation was considerably reduced in the former cells but not in the latter cells, suggesting that PT-sensitive and PT-insensitive GTP-binding proteins are involved in phosphoinositide phospholipase C (PI-PLC) activation in fibroblasts and neuroblastoma cells, respectively. In NG108-15 cells down-regulated in protein kinase C (PKC) by long-term exposure to phorbol 12-myristate 13-acetate (PMA), BK-stimulated Ins(1,4,5)P3 accumulation was significantly enhanced compared to control cells.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Dec 30 1988|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology