title: Influence of ATP on Ehrlich ascites carcinoma cell free cytoplasmic calcium concentration in the course of tumor growth.
abstract: The changes in free cytoplasmic calcium concentration ([Ca2+](in)) and the effects of extracellular ATP on [Ca2+](in) have been studied in Ehrlich ascites carcinoma cells in the dynamics of their growth. The basal level of [Ca2+](in) and the effects of ATP on the ascites cells were determined by the stage of tumor growth and depended on the content of reactive oxygen species (ROS). The sharp increase in basal and ATP-induced elevation of [Ca2+](in) levels were observed at the 12th day of ascites cell growth. Inhibition of ROS formation by N-acetyl-L-cysteine decreased [Ca2+](in) and suppressed the cell reaction to ATP. We suggest that the increased sensitivity of the ascites cells to ATP observed on the 12th day may be also attributed to a decrease in ecto-ATPase activity.
authors.affiliation: Krasnoyarsk State University, Krasnoyarsk, 660041, Russia.
authors.forename: T N
authors.initials: TN
authors.lastname: Zamay
authors.forename: A S
authors.initials: AS
authors.lastname: Zamay
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism / Q000473:pathology; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism*; D004533:Egtazic Acid / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D017382:Reactive Oxygen Species; D004533:Egtazic Acid; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C027201:ectoATPase; D002118:Calcium; D000111:Acetylcysteine