Cytosolic Ca 2+ levels in CO25 myoblast cells bearing a human N-ras oncogene after stimulation by thap-sigargin and growth factors

Authors : Hülya ZEYTİNOĞLU

Pages : 159-168

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Publication Date : 1999-12-01

Article Type : Research Paper

Abstract :The levels of intracellular calcium [Ca 2+ ]i were examined in CO25 myoblast cells bearing a mutated human N-ras oncogene, after stimulation by thapsigargin insert ignore into journalissuearticles values(ThG);, bombesin and epidermal growth factor insert ignore into journalissuearticles values(EGF);. Thapsigargin induced a [Ca 2+ ]i rise mostly from intracellular calcium pools, and a small Ca 2+ entry into cytoplasm via the plasma membrane channel. In both ras-induced and differentiated CO25 cells, [Ca 2+ ]i increase showed a similar pattern of events after addition of ThG. The addition of EGF and bombesin to both ras-induced and differentiated cells did not induce Ca 2+ mobilization, suggesting that the cells may not have receptors for the ligands, or desensitization of the receptors may have occured by a different signalling pathway such as stimulation of protein kinase C activity.
Keywords : N ras, myoblast, Ca 2 i, thapsigargin, EGF, bombesin