Cholecystokinin induced signaling in rat glioma C6 cells.

We investigated the effect of sulphated cholecystokinin octapeptide (CCK-8S) on free intracellular calcium concentration, phosphatidylinositol metabolism, and protein phosphorylation in C6 cells, a rat glioma cell line which was shown to express CCKB type receptors. Increase in [Ca2+]i by both influx across the cell membrane and release from internal stores was demonstrated by utilizing a laser confocal imaging system. Because CCK-8S produced a transient elevation of inositol triphosphate level participation of InsP3 in calcium signaling in C6 cells is very likely. Protein kinase C seems to be involved in CCK-8S induced signaling in rat glioma C6 cells as demonstrated by using in vivo phosphorylation experiments.