ABSTRACT
Calcium is an essential regulatory element for cellular structures and functions, including those related to cell proliferation and cell differentiation. 1 An increase in intracellular concentration of free calcium ions, [Ca2+]i, caused by hormonal or electrical signals, can trigger in different cell types a diversity of responses, including contraction and secretion, as well as changes in metabolism and gene expression. 2 Calcium is involved in the regulation of intercellular communication through gap junctions and can trigger the terminal differentiation program of cells. It has an important role in the programmed cell death (apoptosis) of differentiated senescent or functionally superfluous cells that is required for the maintenance of body homeostasis. 3
