NEUROLIGAND-TRIGGERED CALCIUM SIGNALING IN CULTURED HUMAN GLIOMA-CELLS

Cells from primary cultures of four glioblastomas (GB), three low-grad e astrocytomas (A), and four low-grade oligodendrogliomas (O) were tes ted for the presence of neuroligand receptors linked to Ca2+ signallin g by calcium imaging. Cells of days 3 to 21 in culture were incubated with 5 mu M fluo-3-acetomethylester in a bath solution and stimulated with 0.1 mM ATP, 0.01 mM angiotensin II, bradykinin, histamine, norepi nephrine, serotonin, and substance P for 15 a, with 0.01 mM glutamate and 50 mM K+ for 30 s. Changes in the Ca concentration were measured w ith a confocal laser scanning microscope. In all glioma subtypes, the majority of cells showed Ca responses after application of histamine ( 60% of cells tested in GB, 67% in A, 86% in O), bradykinin (66% in GB, 29% in A, 55% in O) and ATP (48% in GB, 70% in A, 47% in O). The othe r stimuli induced Ca2+ transients in a smaller proportion (between 33% and 2%) of the cells. Our study demonstrates that histamine, bradykin in and ATP are potent inducers of [Ca2+](i) signals in gliomas. (C) 19 97 Elsevier Science Ireland Ltd.