In the past 5 years there has been an enormous increase of evidence that the ion channels activated by mechanical force are common to a wide variety of cell types. Mechanosensitive (MS) ion channels form a small proportion of the total channel population. They are now found in more than 30 cell types from E. coli, yeast, to plant, invertebrate, and vertebrate cells, where they occur in virtually all types of cells from bone to smooth muscle, as well as neurons. The majority of MS channels are permeable to monovalent cations and are slightly selective for K+ over Na +. How 2 ever, there are...