Capacitative Ca2+ entry involves Ca2+ influx factor in rat glioma C6 cells.
Capacitative Ca2+ entry exists in rat glioma C6 cells; however, how the information of depletion of Ca2+ in intracellular stores transmits to the plasma membrane is unknown. In the present study, we examined whether Ca2+ influx factor (CIF) causes capacitative Ca2+ entry in C6 cells. CIF was extracted from non-treated (Non-CIF), bombesin-treated (BBS-CIF) and thapsigargin-treated (TG-CIF) C6 cells by a reverse-phase silica cartridge. The addition of BBS-CIF and TG-CIF gradually increased cytoplasmic Ca2+ concentration ([Ca2+]i) but Non-CIF did not increase [Ca2+]i. Neither BBS-CIF nor TG-CIF elevated [Ca2+]i in the absence of extracellular Ca2+. Gd3+ inhibited the increase in [Ca2+]i induced by BBS-CIF and TG-CIF. Genistein abolished an elevation of [Ca2+]i induced by BBS-CIF and TG-CIF. BBS-CIF and TG-CIF did not increase inositol 1,4,5-trisphosphate accumulation. The results suggest that capacitative Ca2+ entry is caused by CIF in rat glioma C6 cells.
Takemura
H
H
Department of Pharmacology, School of Medicine, Sapporo Medical University, Japan.
Ohshika
H
H
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000242:Cyclic AMP / Q000096:biosynthesis; D019833:Genistein / Q000494:pharmacology; D005910:Glioma / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000096:biosynthesis; D051381:Rats; D014407:Tumor Cells, Cultured
D015544:Inositol 1,4,5-Trisphosphate; D019833:Genistein; D000242:Cyclic AMP; D002118:Calcium