Characteristics of the ATP-Induced Ca²⁺-Entry Pathway in the t-BBEC 117 Cell Line Derived From Bovine Brain Endothelial Cells

Abstract

ATP-receptor (P2Y) stimulation induced sustained Ca²⁺-entry, which was essential for the enhanced cell-proliferation in t-BBEC117, an immortalized cell-line derived from bovine brain endothelial cells. Application of Ca²⁺ following store-depletion with thapsigargin in Ca²⁺-free solution induced Ca²⁺-entry through store-operated channels (SOCs). Ca²⁺-entry induced by ATP or 1-oleoyl-2-acetyl-sn-glycerol (OAG) together with Ca²⁺ was significantly larger than that by Ca²⁺ alone, suggesting the involvement of receptor-operated channels (ROCs) in the Ca²⁺-entry. Results obtained using pharmacological tools suggest that the contribution of Ca²⁺ sources to ATP-induced [Ca²⁺]_i rise in t-BBEC117 is estimated as approximately 2:1:2 for Ca²⁺-release and Ca²⁺-entry though SOCs and ROCs, respectively.