Kopach O. Role of endoplasmic reticulum for the regulation of intracellular Са2+ signaling in acinar cells of rat submandibular salivary gland

Ca2+ release from the intracellular Ca2+ stores in acinar cells of rat submandibular salivary gland was investigated. It was shown that activation of m-cholinoreceptors led to the Ca2+-dependent changes in the secretion by acinar cells of submandibular salivary glad. We have elaborated experimental models for studying Са2+-dependent exocytosis and direct measurements of Ca2+ inside the ER in permeabilized cells. It was elucidated the presence of ІnsP3-dependent thapsigargin-sensitive and -insensitive Ca2+ stores in acinar cells and studied the characteristics and regulation of InsP3 receptor. We established a contribution of ryanodine receptors to the Са2+ signaling in acinar cells and postulated the co-localization of mitochondria, Ca2+-ATPase and ryanodine receptors. It was suggested that passive Ca2+ leak from the ER occurs via a translocon pore. We have analysed the amplitude and kinetic of store-operated Ca2+ entry and have found the role of mitochondria in support of Ca2+ entry in the acinar cells.