Synthetic ion channels are of great interest in mimicking the biological functions of natural ion channels. Although many synthetic ion channels could selectively mediate ion transport across lipid bilayer membranes, the biological roles played by these synthetic channels in living systems remain essentially obscure. In this study, we report the application of a synthetic chloride (Cl-) channel as a powerful tool to perturb and regulate a series of biological processes related or coupled to the changes of cell membrane potentials. This is the first example in which an artificial ion channel can regulate natural voltage-gated calcium channels, intracellular calcium concentrations, and the contraction of smooth muscle cells via modulating cell membrane potentials in living cells and tissues. The present study on the ability of the synthetic chloride channel to perturb functions of natural ion channels may open new perspectives for the applications of other synthetic ion channels in biological systems.