ABSTRACT

This chapter focuses on the role of chloride (Cl-) channels in smooth muscle. The membrane potential of smooth muscle cells is modulated by the patency of different ion channels positioned in the cell membrane. To understand the role of Cl- in smooth muscle it is important to know how it is distributed within the intra- and extracellular spaces. Intracellular Cl- concentrations in smooth muscle are higher than expected if Cl- ions were passively distributed. Furthermore, hyperpolarization of the membrane potential, and relaxation of aortic smooth muscle were caused by a furosemide-induced reduction in intracellular Cl-. cystic fibrosis transmembrane conductance regulator, studied extensively in epithelial cells, has also been found in cardiac myocytes as well as vascular and non-vascular smooth muscle. Consistent with the studies of CACCs in smooth muscle, TMEM16A is implicated in the development of contraction in a variety of smooth muscle types, vascular in particular.