Cytosolic Ca²⁺ alteration mediates both ryanodine receptor and IP₃ receptor in TE671/RD cells

抄録

TE671/RD is a cell line obtained from the rhabdomyosarcoma cells. In the present study, we examined [Ca²⁺]_i alteration induced by acetylcholine (ACh) in TE671/RD cells with the special attention to ryanodine receptor (RyR) and inositol 1, 4, 5-trisphosphate receptor (IP₃R). The change of [Ca²⁺]_i was mediated by muscarinic type 3 (m3) AChR. Both phosphatidylinositol-specific phospholipase C blocker (U73122) and IP₃R blocker (2-APB) inhibited ACh-induced [Ca²⁺]_i elevation, suggesting that IP₃ pathway is involved in [Ca²⁺]_i alteration. Ryanodine and FK506 increased ACh-induced [Ca²⁺]_i elevation, which was decreased by RyR blocker (ruthenium red). These results suggest that RyR and FK506 binding protein 12 kDa (FKBP12) complex was involved in [Ca²⁺]_i change, and that TE671/RD cell line has a hybrid characteristic of smooth and skeletal muscles.