A locally‐induced increase in intracellular Ca2+ propagates cell‐to‐cell in the presence of plasma membrane Ca2+ ATPase inhibitors in non‐excitable cells

Intercellular Ca2+ waves are commonly observed in many cell types. In non‐excitable cells, intercellular Ca2+ waves are mediated by gap junctional diffusion of a Ca2+ mobilizing messenger such as IP3. Since Ca2+ is heavily buffered in the cytosolic environment, it has been hypothesized that the contribution of the diffusion of Ca2+ to intercellular Ca2+ waves is limited. Here, we report that in the presence of plasma membrane Ca2+ ATPase inhibitors, locally‐released Ca2+ from the flash‐photolysis of caged‐Ca2+ appeared to induce further Ca2+ release and were propagated from one cell to another, indicating that Ca2+ was self‐amplified to mediate intercellular Ca2+ waves. Our findings support the notion that non‐excitable cells can establish a highly excitable medium to communicate local responses with distant cells.